Image 1: Rookie (top) or veteran (bottom, Jack Lalanne), their hormonal response to push-ups is different, but does not explain the different outcomes of strength training.
If you are a regular, here at the SuppVersity, you will have hear me lament the fact that in many of the mainstream studies on the effects of exercise on body composition, endocrine parameters and so on, the study participants are either sickly, obese or both... admittedly, whenever measures of muscle hypertrophy are involved, the subjects are usually healthy rookies, which is by no means better, as you all know from your first weeks in the gym that, despite doing everything wrong, your strength and size gains were tremendous. Now, the obvious question is, are the endocrine adaptations / responses distinct, as well? According to the results of a recent study by Rasani Ranjbar et al. they are (Hasani-Ranjbar. 2011) - surprisingly, though, on paper, the endocrine milieu of the veterans appears more conducive to strength and size gains than that of the rookies... but let's take a look at the actual results, before we even start discussing their implications.
The Iranian scientists recruited 15 previously strength trained and 19 untrained male (how else could it be in this lovely country?) students at the Tarbiat Moallem University, divided them in an experimental (trained) and a control group and took blood samples at 10am (pre-test) after the students, who had arrived at the lab at 7am, had been served identical breakfasts (at 7:30-8:00am). Subsequently, the training groups (E1 = previous strength training experience; E2 = rookies) performed a resistance training protocol at 70-80% of their maximum strength in the 10-12rep range (i.e. a classical "hypertrophy training"), consisting of 4 sets of chest presses, stretch wires [I have no clue what kind of Iranian specialty that is], leg extensions and leg curlsto failure with rest times of 2 minutes in between sets and 4 minutes between exercises.
Figure 1: Training induced changes in growth hormone (GH) compared to untrained control (Hasani-Ranjbar. 2011).
Blood was drawn at four timepoints: pre-test (T1), immediately after cessation of the exercise session and before lunch was served (T2), five hours post training (T3) and seven hours post training (T3). The samples were analyzed for growth hormone (GH), insulin, insulin-like-growth-factor 1 (IGF1), IGF1 binding protein 1 and 3 (IGFBP1 & IGFBP2). I have plotted the relevant data (i.e. data where you see meaningful changes) in figures 1 & 2.
Figure 2: Training induced changes in insulin and IGF1 compared to untrained control (Hasani-Ranjbar. 2011).
Now, what do we make of these results? Obviously the immediate GH response to resistance training is more profound in the veteran group, it is yet more sustained in the rookies, whose insulin levels interestingly skyrocket in the late post exercise period, yet in the absence of any significant increases in IGF1 levels (the same was true for the binding proteins) over the untrained control group.
Figure 1: Absolute IGF1 levels (in ng/ml) in trained and untrained rookies and veterans (Hasani-Ranjbar. 2011).
I don't know which data the Iranian scientists analyzed, but despite the fact that there is as they state a steady decline in IGF1 this probably isn't a result of the strength training regimen (as the Iranians would have it) but simply related to the lack of food intake in the 5-7h post lunch, which was ingested right after the post blood draw, i.e. exactly 5 hours before the 5h post blood was drawn....
Be that as it may, the more relevant result is that there may be differences in the endocrine response to exercise, but those are exactly contrary to what we would have to see, if the highly marketable GH increase, you are supposed to spike with all sorts of supplements had any effect on your gains in the gym. After all, you bet that if any of the two groups had had measurable strength or size increases at a subsequent training session / body composition measurement, it would have been the rookie group. That being said, this study further supports the position of the Phillips group from McMaster University (cf. Arms Don't Grow Faster with Prior Leg Training), who maintain that the exercise induced GH increase has absolutely no effect on strength or size gains... in other words, spending money on respective supps or focusing on training techniques that have been shown to increase GH (and have not been shown to be productive in terms of size and strength gains) is not advisable.
Actually, it would make as much sense to split this part of the SuppVersity EMG Series in two, if not three individual analyses, as it would to split your leg workout over two if not three days. In practice, however, most trainees go through the grueling torture of the dreaded "leg day", just once a week and thus I will mirror this practice by writing a similarly gruelingly long blogpost on the best exercises for the major
Image 1: The major muscle groups of your legs. Quadriceps, adductors, abductors, gluteus, hamstrings, gastrocnemius & soleus
the quadriceps (red) - powerful extensors of the knee joint;crucial in walking, running, jumping and squatting; strongest and leanest muscle in the human body
the gluteus (yellow) - three muscles that make up the buttocks: the gluteus maximus muscle, gluteus medius muscle and gluteus minimus muscle;
the hamstrings (blue) - comprises the semitendinosus, semimembranosusand the short and long head of the biceps femoris, of which the former extend the hip when the trunk is fixed, flex the knee and medially (inwardly) rotate the lower leg, when the knee is bent, while the latter extend the hip (e.g when we begin to walk), flex the knee and laterally (outwardly) rotate the lower leg when the knee is bent
as well as the "minor" muscle groups of your legs
the adductors (cyan) & abductors (magenta) at the inside and outside of the tighs, and
the gastromenicus (light green) & soleus (highlighter green), the major muscles of your calves
In the end it is the the muscular development of all of them that eventually distinguishes the men from the boys. And by the way, playing football or, here in Germany, soccer, is no excuse for not training your legs!
Chest
Biceps
Back
Core
Legs
Triceps
Shoulders
Navigate the SuppVersity EMG Series - Click on the desired body part to see the optimal exercises.
In view of the sheer amount of information this part of the EMG Series is going to contain, I will, without further elaborations, go right into an analysis of the most effective exercises, as measured by electromyography (10 male resistance-trained subjects, mean age 22y, mean body-fat 13%; data from Boeckh-Behrens & Buskies. 2000) for all the major and supposedly minor muscle groups of your legs. I. The best exercises for the four heads of the quadriceps Those of you who have read any of the previous parts of this series will already be familiar with the idea of "isolation" being more of a shift in which part of a muscle takes the greatest hit and not so much about training a single strain of a complex muscle such as the quadriceps with its (who would have guessed) four heads. If I am talking about "best exercises for the inner, outer or whatever part" of any given muscle - and this goes for the whole EMG series - what is meant by that is a relative increase in intensity in a given part of a muscle over the rest. Always keep that in mind.
Image 2: Turns out the hack squat is the most effective exercise. In that, going deep (50° knee angle) is only slightly more taxing on the quads than the standard and much safer 90° knee angle.
The most effective exercises with standard equipment:
Hack squats, lying on machine, 50° knee angle
Hack squats, lying on machine, 90° knee angle
Squats, barbell, 70° knee angle
45° leg press, 90° knee angle
Squats, barbell, 90° knee angle
Squats, barbell, 40° knee angle
If you take a look at the results in detail (figure 1), you will notice that the differences between the most (hack squats down to a knee angle of 50°) and the least effective exercise (leg extensions) are far from being earth-shattering.
Figure 1: Relative EMG activity of all four heads of the quadriceps during hack squat, leg press, squat and leg extension variations in comparison to barbell squatting to parallel (knee angle 75°); data adapted from Boeckh-Behrens & Buskies. 2000
What I consider of particular importance is that both in the case of the hack- as well as in the case of the "standard" barbell squat, going beyond parallel (knee angle <70°) is not worth the increased risk of injury (cf. figure 2).
Figure 2: Shear and compressive forces during squat exercise measured at different knee angles; expressed as percentage of the sum of body weight + load (data adapted from a compilation in Escamilla. 2000)
While the EMG activity of the quads may be marginally improved in the case of the hack squat (+0.38%), doing one's squats "ass to the ground", as some people like to call it, actually reduces the quad activity by -10.34%.
Image 3: 45° leg press with a hip angle of 85°; the smaller hip angle (compared to the hack squat) translates into a -16% lower activity of the quadriceps femoris (image everkinetic.com)
Did you know that the smaller the angle of your hip joint (this is in most cases equivalent to the more upright you are sitting or lying on a machine), the smaller is the EMG activity of the quadriceps femoris. During the hack squat exercise, for example the angle of your hip joint is ~100°, the 45° leg press facilitates an angle of ~85° and on the seated leg press the angle is only ~50°. While this does not lead to an 1:1 reduction in EMG activity, the latter is in fact, -16% and -22,5% smaller for the 85° and 50° hip joint angles on the respective exercises.
Training the inner and outer part of the quads Now, if you are a bodybuilder, you will probably be trying to build those "teardrops" (for all real experts who have no clue what those gym-bros refer to as "teardrops", this is the m. vastus medialis, cf. image 3), which actually does not so much look like a tear drop, as it sometimes takes shedding a few tears to get it growing. With respect to the m. vastus medialis Boeckh-Behrens and Buskies have to say that
[the inner part of the quadriceps] is maximally activated via variants of the horizontal leg presses / hack squats - either deep [knee angle <70°] with less weight or not deep [knee angle >70°] with more weight - variations in weight and knee angle tend to be equivalent.
So after all, even your "tear drops" benefits most if you just keep doing those exercises that hammer the quads, i.e. all four heads, as a whole. A slightly narrower stance, however, may be advantageous, while the positioning of the feet, i.e. parallel or with your feet pointing outward at a 30° angle seems to be negligible (+/- 0.25%).
Figure 3: Relative EMG activity of the outer part of the quadriceps (m. vastus lateralis) during barbell squat and single legged squat variations in comparison to barbell squatting to 90° knee angle; data adapted from Boeckh-Behrens & Buskies. 2000
Image 4: Inner (vastus medialis), medial (vastus intermedius & rectus femoris) and outer (vastus lateralis) parts of the "quads"
As you can see in figure 3, things are quite different, when it comes to the outer part of the "quads". Whereas the standard squat with high loads provides maximal muscle stimulation of the m. vastus lateralis, even if you do not even go down parallel to the floor (knee angle 70°), doing the "full squat" down to 40° with an appropriately lighter weight takes away -18% of the stimulus. Similar results can be seen for the isolation exercise single legged squats, where likewise the principle for maximal muscle stimulation reads more weight, greater knee angles (not going past parallel) - a principle, which can also help you keep injury free, as long as you do not wrench it as long as it say more weight and a smaller knee angle, in which case it is a safe bet that you would hurt yourself - probably sooner, than later. Training the medial part of the quads In view of what has been said before with regards to the maximal activation of the fashionable "teardrop" muscle, it is not really surprising that the usual suspects, i.e. the hack squat and the leg press are among the most effective exercises for the medial part of the quads, i.e. the m. vastus intermedius and the m. rectus femoris, as well.
Figure 4: Relative EMG activity of the medial part of the quadriceps (vastus intermedius & rectus femoris) during selected exercises in comparison to hack squats to a 50° knee angle; data adapted from Boeckh-Behrens & Buskies. 2000
Figure 4 does yet go to show you that there is one relatively unknown "special exercise" for soccer players, as Boeckh-Behrens and Buskies like to call it, that outperforms even the hack squat. It's basically the leg kick you see the ladies do with those straps attached to their ankles in order to build one of those J'Lo-ish behinds, but in this case you do it the other way around, or, as the authors suggest, "think of kicking a ball". The +19% higher EMG activity compared to the hack squat (similar results have been found for the standard leg extensions vs. squats by scientists from the Marquette University in Milwaukee, Wisconsin; Ebben, 2009), suddenly makes, what you probably regarded as one of those ridicolously girly exercises, look like a worthwile addition to your regimen... well, at least, in case you are one of those rare exceptions who have an underdeveloped rectus femoris ;-)
Speaking of girly exercises... while it certainly is manly to squat 500lbs, it is not advisable to do so on a daily base. Even the strongest men in the world regard their training sessions asexactly that, the "process of developing the bodily vigour and endurance by systematic diet and exercise, so as to fit for some athletic feat" (Oxford English Dictionary, "training"), or, in other words, as the means to an end. Remember: King-size egos rarely built king-size quads.
II. The Best Exercises for The Gluteus maximus
Image 5: Atlantic Fitness' interpretation of what Boeckh-Behrens & Buskies call a "hip pendulum"
If you have already taken a look at the data in figure 5, you are probably now asking yourself what this strange leg curl variety that is supposed to activate the glutes ~2.3x as effective as a deadlift is all about. Those of you who read the core-episode of this series and the information about the best exercises for the erector spinae, in particular, will be familiar with its name, however. In essence, this is a standard leg curl, but instead of pushing your ties into the pad you are lying on, you try to lift them up, i.e. to curl your hips back, and forcefully contract the muscles of your lower back, your gluteus maximus and your hamstrings. If that's too complicated for you or just doesn't feel right, you can still look out for what Boeckh-Behrens & Buskies call a "hip pendulum" (cf. image 5) and use that instead.
Figure 5: Relative EMG activity of the m. gluteus maximus during selected exercises in comparison to deadlifts using a weight that matches your own body weight; data adapted from Boeckh-Behrens & Buskies. 2000
Of the exercises without additional weight, only leg kick variations, particularly if they are done with peak contractions and/or ankle weights, provide appreciable muscle stimuli, the intensity of which is about equal to to the leg kicks on the hip pendulum (cf. figure 4). III. The Best Exercises for the Hamstrings For the hamstrings the good old lying leg curls are what biceps curl are for the two-headed muscle of your upper arm. And, in fact, the results of the EMG measurements by Boeckh-Behrens & Buskies confirm that generations of trainees cannot be wrong. Similar to the concentration curls in the case of the biceps, only the use of intensity techniques, i.e. partials in the stretch position or peak contractions elevates the already phenomenal EMG values of the standard variety of the lying leg curls to 134% and 112% of the activity measured on the reference exercise (cf. figure 5)
Figure 6: Relative EMG activity of the muscles of the hamstrings during selected exercises in comparison to standard lying leg cursl; data adapted from Boeckh-Behrens & Buskies. 2000
Done correctly, i.e. with a leg angle of 100°, the leg or hip lift is the only body-weight exercise that can compete. With <50% of the muscle activity of the standard lying leg curls, hyperextensions, on the other hand, will do little for your hamstring development.
Did you know that doing partials and peak contractions is particularly effective eccentric exercises? On concentric exercises such as the squat, on the other hand, they increase your chance of getting injured and contribute little to the efficiacy of your training. Tip: If you are talking to your gym partner or, god-behold, your clients about these intensity techniques, you better not call them "X-reps "- otherwise you could be charged by some clever business men who know how to relable training techniques that have been around ever since the early days of physical culture in order to monetize on these "revolutionary new training techniques".
Image 6: An adductor machine, as you probably know it from your gym, as well.
IV. The Best Exercises for Adductors and Abductors
As you probably have expected, the adductor and abductor machines that are mostly operated by the female gym members, are the reference exercises to train the muscles on the inner and outer sides of your tighs. Unfortunately the build of these machines varies from one manufacturer to another, so that you can hardly be sure whether or not your adductor machine will produce the same muscular activation as the ones used in the study. The same holds true for the funky hip pendulum machine, the use of which as an adductor or abductor trainer is pretty tricky, anyways.
Figure 7: Relative EMG activity of the adductors and abductors during selected exercises in comparison to the respective machines (since the exact value for the abductor machine was not given by the authors, the latter is an estimation based on the rank of the exercise); data adapted from Boeckh-Behrens & Buskies. 2000
Viable alternatives for these machine based exercises are the cable adduction(moving leg pulled in before the stabilizing leg) and, probably to the surprise of those among you who refrain from doing body weight exercises completely, the side bridge with hip abduction.When you are squatting, on the other hand, only the adductors are significantly involved in stabilizing the movement. To further increase their activity, you can do your hack squats with a wider stance and your toes facing slightly outward (30°), which will increase the load on your adductors and intensify the exercise by +3%. V. The Best Exercises for the Calves While chicken legs are no exception especially in many of the fitness oriented gyms, toothpick calves are becoming more and more the rule, especially among those trainees who love to do their endless cardio sessions on an elliptical. At the same time few people want to spend an adequate amount of time in training their calves. It is thus all the more important to know which exercises are effective and which are not.
Figure 8: Relative EMG activity of the calf muscles during selected exercises in comparison to the standing calf raises; data adapted from Boeckh-Behrens & Buskies. 2000
As you can see, you cannot avoid doing any variety of calf raises unless you are satisfied with a >65% reduction in muscle activity of the calves when you are doing your lying leg curls for your hamstrings. That being said, there are a few tweaks that make the exercises even more effective. The first, thing you can always incorporate are peak contractions and forced contractions in the stretched position. Moreover, it is imperative that you do not actively bend the knees during the seated calf raise (no bouncing!), if you do not want to reduce the muscle activity by -11%. And in a similar vein, you also do not want to mess with foot position, because (surprisingly?) the parallel foot position is the one that activates the inner, as well as the outer part of the m. gastrocnemius maximally (cf. figure 8)!
Figure 9: Relative EMG activity of the m. gastrocnemius with different foot positions; data adapted from Boeckh-Behrens & Buskies. 2000
In that, it is worth mentioning that the overall activation of the calves is maximized during standing and bent-over (donkey) calf raises, while the m. soleus activity is highest when you do seated calf raises.
A rule of thumb with regards to the activation of m. gastrocnemius vs. m. soleus is "maximize knee angle (as in standing calf raises or donkey calf raises) to maximize gastrocnemius, minimize knee angle (as in seated calf raises) to maximize soleus activity". Note: It is nonetheless imperative (especially if you are using higher loads) not to forcefully lockout your knees, in order to avoid injury.
Image 7: "Real men" ain't ashamed of doing donkey calf-raises like Dave Draper and Arnold used to do it ;o)
Last but not least, a short note on the "high reps for calves"-myth. While I do not question that many trainees just don't feel their calves working, if they do not go into the 50+ rep range, this is not due to the anatomy, the fiber type or whatever crazy anomaly of the calf muscle, but simply due to a faulty execution of the respective exercises. Bouncing, not utilizing the full range of motion and insufficient time under tension (1 sec up, 1-2 sec hold, 3 sec down, would be an appropriate way to go), the by far commonest mistake I see in the gym is turning your calf into a toe exercise by not pushing from the balls of your feet, but from the toes. Now guess what, it takes some time until your toes are finally fatigued and your calves get some work to do ... what would you say, maybe 20-30 reps? Hmm... that would mean that of your 50 reps of calf raises 30 are toe raises and the last 20 actually train your calves - does not sound particularly effective, does it? V. Conclusion: Too Much Work for a Single Day! Now, that you have arrived at the end of this concise and yet super-long write-up on leg training, you should actually ask yourself how and why you have hitherto packed all that stuff into a single workout. Well, I guess, after all, this is a very reasonable question. Nevertheless, fitness competitors and body builders alike have demonstrated time and again that a single "leg day" per week can suffice to build spectacular legs. Is this all genetics or are those guys (and, of course girls) spending the whole day in the gym?
Video 1: Arnold leg training compilation; only the strong will survive ;-)
Did you know that Arnold Schwarzenegger, as a teenager took a barbell into the woods, where he and his friends squatted till they couldn't stand. This does not go to say that this would be the way to go for anyone - especially not the drug free weekend warrior who just wants to keep in shape, but leg-day or not, whenever you train your legs you should take a look at your toothsticks and ask yourself "How many sets have I done for chest, biceps and triceps this week?" If you did more for those than your did for your legs, you better add another set of squats.
Well, I guess some of the "pros" actually spend the whole day in the gym, but a lot of dedication aside, most of them also use an array of "special equipment" to make those workouts extra productive. My personal experience, on the other hand, tells me that legs can in fact sustain much more volume than many trainees claim from themselves (cf. "Did you know...", above). Yet, while I would think that it was possible to do at least a single working set of all "optimal" exercises, the "EMG-optimized routine" I am going to suggest below deliberately shifts the focus from those "optimal" isolation exercises to the optimal varieties of those compound movements that have built such incredible powerful 38"+ tighs on which Tom Platz and some other old school bodybuilders were walking through the gym.
Did you know that compound exercises such as squats and deadlifts have been found to increase the hormonal response to strength training? Well, I guess you did. What may however be news to you is that these temporary increments are hardly going to exhibit those steroid-like effects some trainees seem to be expecting. This does not mean that the value of these exercises is overrated (on the contrary!), but rather that the increase in GH or testosterone after an intense squatting workout is corollary to, not causative of the efficiacy of these exercises.
The reason for that is quite simple: While a set of barbell squats may not activate your glutes like the strange hip pendulum, your quads like the Beckham-ish leg kicks and your adductors like the girly adductor machine, it will nevertheless build adequate power and mass in all three of these muscles, fortify your core, your calves, your upper back and even help with conditioning and fat loss. In other word, as gruelling as they may seem compared to some of the machine based isolation stuff, compound exercises will still give you the most bang, in this case muscle and strength gains, for your bucks, i.e. the time you spent and the energy you invest in the gym.
Image 8: As long as you are injury free, there is noo way to get around squatting - one way or another (image everkinetic)
If you cannot do squats use leg press machines instead.
As a beginner always have a qualified trainer show you how to squat.
An EMG-optimized routine There is of course a myriad of ways of combining the individual exercises, my personal recommendation for overall leg development (based on EMG measures) would yet be as follows*:
Squats - to parallel (70°), 6-10 reps
Hack squats - to 90°, 8-12 reps
Leg curls - peak contract. or partials, 10-12 reps Superset:
Donkey calf raise - peak contract., 12 reps
Seated calf raise - partials, 12 reps Optional
Adductor machine - 12-15 reps
Abductor machine - 12-15 reps
You may notice that I do not make volume (i.e. set) recommendations. This is due to the fact that I found that everyone has to find what works best for him / her in terms of optimal volume and training frequency. This may also change over time / according to lifestyle factors / nutrition and supplementation.
Finally, a study (Roschel. 2011) related not only to nutrition and supplementation for exercise, but to exercise itself! The respective paper was published in the Applied Physiology, Nutrition, and Metabolism on April, 13th, and reports the results of a study on the effects of exercise velocity on markers of muscle hypertrophy, specifically, Akt/mTOR/p70s6k.
Roschel, et al. had 20 subjects, "not enrolled in any form of strength training for at least 6 months prior to the study and without any history of musculoskeletal disorders" perform 5 sets of 8 repetitions of an eccentric knee extension exercise at either a slow (20°·s–1; ES) or fast execution speed (210°·s–1; EF). After the workout, biopsies were taken from vastus lateralis at three timepoints: baseline (B), immediately after (T1), and 2 h after (T2). The results did not confirm the scientists' working hypothesis that execution velocity (and thus muscle tension) would have a direct influence on Akt, mTOR, and p70S6K expression in the trained muscles:
Akt, mTOR, and p70S6K total protein were similar between groups, and did not change postintervention. Further, Akt and p70S6Kprotein phosphorylation were higher at T2 than at B for ES and EF. MGF messenger RNA was similar between groups, and only significantly higher at T2 than at B in ES.
So, with respect to the measured variables and in the confounding case of eccentric exercises, it does not matter whether you whack your reps out at maximum speed (assuming you still maintain adequate form) or try to slow the movement down deliberately. I guess this, aside from their (ab-)use certain "supplements", is why Coleman and Co. grew monstrous muscles despite training with the worst form you could probably think of.
Remember though, the results could be completely different for concentric exercises, like pressing movements or for equal times under tension, meaning 10x more repetitions in the EF group to make up for the total time difference. Results from previous studies, such as Farthing and Chilibeck (2003) and Shepstone et al., for example suggest that compared to slow training a faster (yet still controlled) exercise execution is linked to greater hypertrophy of the elbow flexor, in general, and the biceps' type IIa (+16%) and type IIx (+18%), in particular. I guess future studies will further elucidate the exact mechanisms and guess what: the SuppVersity is where you will read about them, first!
I guess you will be remembering last week's post on the superior growth effects of full vs. partial squats, hah? Now, the results of the Bloomquist study certainly raise the question, whether the same or similar effects must be observe with different exercises or even different body parts, as well. After all, it would be bro-science at its best to generalize the result "full squat = full quad development" to "partial ROM = partial strength and hypertrophy response" without the least hint of evidence that this hypothesis is more than just the "proposition or principle put forth or stated (without any reference to its correspondence with fact) merely as a basis for reasoning or argument" ("hypothesis, n.". OED) the word "hypothesis" implies - right?
The good news is that it appears as someone has heard my lamentations about the scarcity of respective research, or - what's in this case more probably - feel the same about the necessity to generate data that would be necessary to base our workout protocols on more than just "hearsay", hypothesis and "N=1 experiences" and a single study.
Ok, enough kiddin' around let's get to the facts
Table 1: McMahon's interpretation of an "ecologically valid resistance training program"; * denotes static holds for time in s, DL = double, SL = single legged (McMahon. 2013)
Despite the fact that the study I tried to make tempting to you in the introduction is again build around a leg training routine, it has two major advantages compared to the Bloomquist study: (1) The participants performed a complex, multi-exercise leg-training protocol, (2) the study used the vastus lateralis as yardstick for the size gains, (3) the effect of full vs. short ROM (range of motion) on strength, muscle structure and body fat were also measured and (4) the study had an active training part (8 weeks on the protocol outlined in table 1) and - and this is pretty unique - a subsequent 4-week follow-up in which the subjects did not train (detraining) that allow us to determine whether the persistency of the gains will also depend on whether you achieved the training with a limited 50° vs. a "full" 90° specific angle of knee flexion (McMahon. 2013).
With the the specified angle being defined as the "position at which the training load is held isometrically for two seconds",
the 50° regimen involved a shorter ROM (SR) in the dynamic phase of the exercise and thus a shorter ‘average muscle length’, whereas
the 90° regimen involved a longer ROM (LR) in the dynamic phase of the exercise and thus a longer ‘average muscle length’
*you will learn more about the importance of muscle lengthening later this week, so stay tuned!
McMahon & Onambélé-Pearson hypothesized that the group training "at longer muscle length" (90°) would undergo a greater amount of skeletal muscle hypertrophy and concomittant strength development and that these differences would be "due to increased physiological stress and stretch on sarcomeres compared to the group training at 50°" (McMahon. 2013) and that these effects would be evident even during / after the deloading phase.
Figure 1: Cross sectional area (CSA) of the vastus lateralis measured at 25, 50 and 75% of the femur length for the full range (LR), partial range (SR) and a non-exercised control group (McMahon. 2013)
If we take a peak at changes in muscle cross sectional area (CSA) in figure 1 this hypothesis appears to be roughly accurate. There are however significant differences in the growth response the scientists measured at 25%, 50% and 75% of total femur length (VL25-75), with a statistically non significant advantage for the high(er) load, short-ROM approach (the higher load is a natural consequence of the RM prescription) and a highly significant advantage for the low(er) load, full-ROM approach, when it comes to that part of the muscle you want to shine, as it contributes to that massive "tear-drop look".
"CSA increased significantly (p<0.05) relative to baseline following training at all sites in both training groups. The significant training effect remained during the whole detraining period in both training groups at both 50% and 75%, but was not evident at 25% of femur length after week 10. There was a trend for LR to exhibit greater relative gains in a CSA compared to SR at all sites, which was significant at week 8 at 75% of femur length. It was found that there was not only a main training effect (p<0.05) but a main group effect after week 8 (p<0.05) with LR exhibiting a 59±15% compared to SR showing 16±10% increment in VL CSA." (McMohan. 2013)
To the surprise of the researchers, the "following the first two weeks of detraining the group effect was no longer evident (p=0.07)" (McMohan. 2012). In the end, the existing advantage of training over the full-ROM, as pronounced as it may be at the CSA75 site, is thus short lived in this group of previously non-resistance-traind 26 volunteers (14 males and 12 females). The fasicle length, which increased by 23±5%, 19±4%, 16±4% at weeks 8, 10 and 12 in the LR and by only 10±2%, 6±2% and 2±2% in the SR group (data not shown), on the other hand, were persistent - yet only in the full range (LR) group.
"And body fat? What about the body fat"
Crossfit doesn't fit well with everyone. In fact, you have to be pretty fit already if you intend to benefit - specifically if you don't have someone who tailors the workouts to your specific needs. If you the shed 8% of your already low 16% body fat in 10 weeks workout routine I wrote about in February, chance is you'll just get injured or burned out (learn more)
The local reduction in subcutaneous fat that was likewise assessed based on the ultra-sound images the scientists used to evaluate the structural changes and CSA increases did not show significant group effects at 25%. The relative changes of 5% in the partial (SR) and 22% at the 50% measuring mark in the full ROM (LR) groups, clearly suggest that "going all the way" would still be the way to go if you don't want to look hypermuscular, but lean (ladies?). The latter is particularly true in view of the facts that the ...
"[...] main effect of group remained during weeks 10 and 12, as SR regressed toward baseline by week 12, whereas LR still possessed significant losses at this phase (-10±6%)" (McMahon. 2013)
and that there was a similar trend seen at 75% where a main effect of both group and training existed at week 8 (p<0.05) - even if the latter vanished in the course of the 4-week detraining period 7±3% SL and 9±1% LR).
Regional growth and angle-specific strength gains Contrary to all previously reported values, which were - if they were group specific at all - regionally different, the changes in strength showed - as you would expect it - an angular specificity. While both groups did increase their strength, there were more than just minute differences between the partial (SR) an the full ROM (LR) groups:
at the end-ranges, the maximal volunary contractive force increased 5±10 for SR at 50° and 30±5% for LR at 90°, respectively
there was evidence of angular specificity of training in both groups with SR significantly (p>0.05) increasing MVCs at 50, 60, 65, and 70° , only, wheres the participants in the LR increased their MVCs values over the entire angular range.
What's remarkable, yet non necessarily beneficial, is the fact that the angle of peak torque which had been 75° at the beginning of the training intervention decreased to 70° within 8 weeks of training over the short ROM (SR) and remained there for the duration of the detraining (i.e. the change was at least persistent, if not permanent). No such effect was observed in the LR group.
"By week 10, both groups displayed an average 6±2% strength reduction (relative to the post-training strength values), with SR not significantly above baseline (0±2%) in contrast to LR remaining significantly above both baseline (p<0.05) and SR (p=0.027) at weeks 10 and 12."
Overall, the changes in contractile force and the angle at which they were elicited reflect the structural changes that were brought about by the more pronounced muscle lengthening that's a prerogative of training over the full range of motion (ROM).
To ensure that all participants conducted the complex exercises at the correct knee angle a goniometer was attached to their knees (photo velamed.com)
Bottom line: As far as the practical implications of his findings are concerned McMahon and Onambélé-Pearson reemphasizes that the specific muscle mechanics are of paramount importance, "when choosing a range of motion for a resistance training protocol." (McMahon. 2013)
With resistance training protocols that enforce a full range of motion having the ability to influence force and power production to a greater extent than protocols where the range of motion is not as extensive, he is therefore right to point out that it would be a mistake to allow your ROM to be compromised "in order to accommodate a greater absolute external load, in an attempt to increase the stress of mechanical loading" and advises coaches to "reinforce a more complete ROM, even when absolute load maybe reduced, in order to provide a greater internal stress and more potent stimulus for adaptation" (McMahon. 2013).
Aside from the fact that this advice is obviously as relevant for trainees, like yourself. The one thing I would like to add to McMahon's "bottom line" is a reference to the structural changes and their importance in view of maintaining the strength gains you achieved. Moreover, it is, as you will be learning in an article I am still working on, likely that the extend of the observed and accompanying, but not evaluated changes in muscle structure facilitate future muscle gains. Therefore, you would in fact be ill-advised not to "leave your ego at the door" if you want persistent size gains and increases in strength over the full range of motion that do not vanish, when you are taking 2 weeks off.
Handpicked suggested reads:
The Jack-of-All-Traits Leg Workout from the Sáez de Villarreal study I discussed on July 15, 2012, would also be something you may want to look into if you need some inspiration for your own routine.
You Want Maximal Performance & Size Gains + Complete Thigh Development? Then Full Squats are For You! (read more)
SuppVersity EMG Series - Gluteus maximus, Quadriceps femoris, Gastrocnemius, Soleus & More: The Very Best Exercises for Tree-Trunk Legs and Herculean Calves (read more)
The Step-By-Step to Your Own Workout Routine Guide (read it)
All posts leg training at the SuppVersity (read them)
References:
"hypothesis, n.". OED Online. March 2013. Oxford University Press. 6 May 2013 <http://www.oed.com/view/Entry/90588?redirectedFrom=hypothesis>.
Eugene McMahon G, Onambélé-Pearson G. Impact of range-of-motion during ecologically valid resistance training protocols, on muscle size, subcutaneous fat and strength. J Strength Cond Res. 2013 Apr 26.[Epub ahead of print]
Image 1: Is it not testosterone that makes the difference?
It is an open secret that women are having a much harder time building muscle than men, and it is another instance of (bro-)scientific wisdom that the obvious lack of testosterone in female strength athletes would be the underlying reason. Right from Stuart M. Phillips lab at the Department of Kinesiology of the McMaster University in Hamilton, Ontario, Canada, comes a new study (West. 2012) which puts yet another questionmark behind the anabolic prowess of testosterone (if you still believe that a transient increase in testosterone will help you build muscle, I suggest you read up on "The Big T" in the Intermittent Thoughts on Building Muscle).
Women are different, but it's not about protein synthesis
In the recently conducted trial Daniel W.D. West, who has also been the lead author of the "Never Sip Your Whey" study, I covered back in November 2011, undertook another attempt to identify the intricate endo- and paracrine mechanisms of skeletal muscle hypertrophy and its sex-specific variability. To this ends, West et al. recruited 5 male and 5 female subjects, who "who were habitually engaging in two to five sessions of physical activity per week including", yet did not train legs more than twice a week.
Image 1: In this case, testosterone took a backseat, as well. With synthol, protein synthesis is yet unnecessary anyway.
Note: The selection of advanced trainees as study participants is the first huge plus of this study. After all, we all know that the exercise induced hypertrophy response diminishes with training and those of you who read the whole Intermittent Thoughts on Building Muscle series will also be aware that the protein synthetic response is limited by the maximal domain size. Further growth thusly requires restructuring / the recruitment of satellite cells and installment of new myonuclei (cf. "Growing Beyond Temporary Physiological Limits"), a time-consuming and complex process which is probably one of the underlying reason for the "growth difference" between beginners and advanced strength athletes.
On the day of the experiment, the study participants, who had consumed a standardized diet containing 15% fat, 30% protein and 55% carbohydrates (the macronutrient ratio was adapted to their habitual diets) on the previous day, reported to the lab at 6am. After the infusion of the tracer that is necessary to evaluate the protein flux and an initial biopsy, all subjects performed a bout of intense, high-volume lower body exercise consisting of
5 sets of 10 repetitions of leg press at ~90% of their individual 10RM, and
3 super-sets of 12 repetitions of leg extension/leg curl at ~90% of 12 RM
The rest intervals between the sets were 60s, so that the whole workout should not have lasted longer than max. 20min. Directly thereafter, the subjects consumed the "obligatory" (for Phillips lab this has in fact become obligatory ;-) 25g of whey protein from the usual New Zelandian source, Phillips et al. used in all their previous study (as ridiculous as this may sound but this is a nice means of standardization ;-) and rested in a supine position for the rest of the trial. Biopsies were taken and the subjects who were sent home with a launch packet consisting of their standardized meals had to report back to the lab on the following morning for another three biopsies 24h, 26h and 28h after the test workout (the subjects remained fasted and received another 25g of whey 26h post, i.e. before the last four blood samples were drawn and the last biopsy at 28h post was performed).
Figure 1: Serum testosterone levels (in nM) and myofibrillar fractional protein synthesis rate (in %/h) before and after the resistance workout, as well as on the morning and at noon of the 2nd day (data adapted from West. 2012)
As the data in figure 1 shows, the (expected) huge difference in both basal as well as exercise induced increases in circulating androgen levels (45-fold in men vs. women) had no (not even a statistically non-significant) beneficial impact on the exercise induced increase in protein synthesis in the 28h window of opportunity (cf. "Opening the 'Anabolic Barn Door' with the Key of Science").
Akt Ser473 phosphorylation increased at 1h ( P < 0.001, main effect for time) and to a greater extent in men(sex × time interaction, P = 0.018). Phosphorylation of mTOR Ser2448 was increased at 1, 3 and 5 h (P < 0.001; Figure 4B); there was a main effect for sex (men > women, P = 0.003). Phosphorylation of mTOR Ser2448 was elevated similarly between sexes after next-day protein feeding, approximately 26 h after the exercise bout (sex × time interaction, P = 0.49; main effect for time, 28 > 26 h, P = 0.006). Phosphorylation of p70S6K1 Thr389 increased at 1, 3 and 5 h (all P < 0.001; sex × tim e interaction, P = 0.13) and there was a significant interaction with next-day feeding (28 > 26 h in women only, sex × time interaction, P = 0.016; data not shown). Androgen receptor content was greater overall in men (P = 0.049) but there was no significant interaction ( P = 0.47).
The greater increase in mTOR and Akt (both hitherto regarded as the "gas pedals" of the skeletal muscle protein synthetic machinery) are not only less pronounced, than one would expect if there was a direct interaction with testosterone levels, they also lack real world significance. After all, the area under the myofibrillar protein synthesis curve (a measure for the total protein synthetic response to exercise) was identical in the 1-5h period right after the exercise and - although West et al. did not include the respective data in their article - I would suspect that the data from the subsequent day (cf. figure 1, right) would even suggest that it must have been slightly greater in the female participants.
Testosterone useless and mTOR and Akt unreliable indicators at best?
Now, which conclusions shall be drawn from these results? Is testosterone useless? Does it not contribute to the overall greater muscle mass in men compared to women? It stands to reason that this conclusion would be about as flawed as the notion that testosterone alone would suffice to build muscle. Rather than its "inefficiency" in building muscle, this study only shows that its importance in relation to the exercise-induced increase in protein synthesis is probably way overrated.
A similar point could be made for mTOR and Akt, as well, though. Or as West et al. put it in their discussion of the results and the respective implications for future studies:
In light of this disconnect, it is worth recognizing that the phosphorylation of signalling proteins is a temporal snapshot of the propagated signal for translation initiation. It is also unclear if there is a minimum threshold signal required to initiate and completely activate or ‘turn on’ translation. If there is such a threshold then it seems plausible that greater phosphorylation above such a threshold would be unlikely to further amplify the signal/lead to increased rates of translation.
For a physicist or anybody who knows a thing about "energy levels" the existence of "threshold" levels in processes taking place at a molecular level should not come as a surprise.
I suspect, we are still missing the boat with our focus on protein synthesis alone
Another question, I have been hinting at in many of my previous blogposts on the insightful studies from Stuart Phillips lab at the McMaster University, is yet whether or not the acute increase in protein synthesis (alone) is actually an acceptable predictor of skeletal muscle hypertrophy, a process which, as I have explained in detail in the Intermittent Thoughts on Building Muscle is only partly mediated by the simple accrual of amino acid chains (=proteins) within existing myofibrillar domains.
Figure 2: Graphical illustration of the processes and their respective triggers which contribute to the exercise induced increase in skeletal muscle mass (click here for detailed elaborations).
If you take another look at the complex network of endo- and paracrine signalling cascades and the number of factors which contribute to a process that is generally reffered to as "skeletal muscle hypertrophy" (cf. figure 2) and is, at least in my mind, falsely reduced to the influx of amino acids into the muscle, it should be clear that testosterone does play a central role in the actual exercise induced growth response. That the latter is less pronounced than bro-science would have it (esp. when we are talking about physiological levels, cf. "Quantifying the Big T") and that testosterone itself and its metabolites, DHT and estrogen are probably of greater importance in the "restructuring" process, which in turn facilitate the accrual of even more protein within the muscle, does after all not imply that the huge differences in androgen levels are not the reason for the differential hypertrophy response in men and women - and I guess, I don't have to tell you that you just have to take a glimpse at the female IFBB (International Federation of Bodybuilding and Fitness) competitors to know that androgens can make a difference ;-)
What's the best you can do after a brutal leg workout? Cardio! At least if size and not strength is your goal...
It is one of those never ending debates: "Cardio!? To do it, or not to do it!? That's the question" - especially for those of us whose main goal is to become big and buffed ... now, you know that my take on this is simple: We are not created as "either or" animals, but have the outstanding ability to make use of both our strength and endurance (just as we can eat both meat and vegetables).
If we discard these philosophical considerations and take a more scientific stance towards the topic, the question still remains: Isn't doing cardio going to interfere with your success on the bench and vice versa? I mean you can't be a marathon running, bodybuilding powerlifter, can you? Hmm... no I don't think so, at least you would be pretty bad in each of the sports - a typical Jack of All Traits, Master of None, so to say ;-)
The "big and bulky" vs. the "sinewy and weak" effect
Not to long ago, the question of "interference" was something only meatheads would ponder. In these days, in which even women's magazines begin to incorporate the latest scientific insights into the importance of muscle mass and strength into their "shaping" and "fitness" routines, it is yet becoming increasingly interesting for "the public" and that makes it easier for scientists to get funding and get published - sometimes (yet not in today's case) even outside of the Journal of Strength and Conditioning Research.
Only a couple of weeks ago, Jacob A. Wilson and colleagues published a detailed meta-review of the interference between strength and endurance work, in which they did confirm that the often-touted interference effect between endurance and strength training exists, and that the extend of the latter latter depends on the amount, type, frequency and intensity of aerobic activity a trainee is trying to pack into his workout routine (click here for the latest on how to combine both into one routine):
Effect sizes for combined training depending on the duration of the endurance component (Wilson. 2012)
"The mean ES for power development for strength training only was 0.91; for endurance training, it was 0.11; and for concurrent training, it was 0.55. Significant differences were found between all the 3 groups. For moderator variables, resistance training concurrently with running, but not cycling, resulted in significant decrements in both hypertrophy and strength. Correlational analysis identified significant negative relationships between frequency (−0.26 to −0.35) and duration (−0.29 to −0.75) of endurance training for hypertrophy, strength, and power." (Wilson. 2012)
I would guess that the timespan between the publication of Wilson's paper in the Journal of Strength and Conditioning Research and the study by Thomas W. Jones et al. the results of which are the topic of today's SuppVersity article probably is too short to call it a "follow up" of some sort. The intention of the researchers, i.e.
"to investigate the strength, limb girth and neuromuscular responses to a variety of concurrent strength and endurance training ratios, with incremental loads in an isolated limb model." (Jones. 2013)
would yet qualify the Jones study as a follow up that could either confute of confirm the statistically derived results Wilson and his colleagues presented in their August 2012 paper.
What did the scientists do and what did they find?
Jones et al. used a balanced, randomized, between-group study design. The participants, 24 healthy recreationally resistance-trained men (25 ± 3 yrs; 82.3 ± 10.0 kg; 179 ± 7 cm; 214.2 ± 42.3 Nm; >2y of strength training experience) were randomly assigned to one of the following experimental conditions:
True or False? "Training your legs will make your arms grow faster" (read more)
strength training, only (ST)
3:1 ratio strength & endurance training (CT3)
1:1 ratio of strength & endurance training (CT1)
no training (CON)
All strength and endurance training was conducted in an isolated limb model and focused on the quadriceps muscle, with the exact protocols looking like this:
strength training alone on all scheduled training sessions (ST)
strength training on every scheduled session with every third session immediately followed by an endurance training (CT3)
strength training immediately followed by endurance training at every scheduled session (CT1)
no strength or endurance training (CON)
The total duration of the intervention period was 6 weeks and all trainees, except those who had been randomized to the lazy control group, worked out three times per week with ~48h of rest in-between the sessions.
"30min of leg extensions = cardio!?"
While the resistance training consisted of 5 sets of 6 repetitions (reps) at 80±5% of unilateral leg extensions (weight was increased progressively to keep the intensity), the endurance training protocol consisted of 30 min of repeated isokinetic unilateral leg extensions at 30±5% individual maximally voluntary contraction. The frequency was set at 1s per muscle action and the tempo was standardized via electronic metronome throughout the trial. This is obviously not a realistic "cardio" program, but it has the advantage of really isolating the targeted muscle group, which would not be the case if the scientists had had their participants cycle on a classic ergometer.
Figure 1: Effects of strength only (ST), strength + "cardio" at 3:1 (CT3) and 1:1 ratio (CT1) and not training at all (CON) on maximal voluntary contraction (strength), limb girth (size) and time to exhaustion (conditioning) - focus on the colors(!) not the figures with their hilariously large standard deviations (Jones. 2013)
As a brief peak at the data in figure 1 is going to tell you (due to the huge standard deviations, you better rely on the colors instead of the figures ;-) the researchers from the Northumbria University in Newcastle upon Tyne (UK) and the North West University in Potchefstroom (SA), the scientists did, just as they had expected, a whole host of statistically significant differences:
"Following training, ST and CT3 conditions elicited greater MVC increases than CT1 and CON conditions (P ≤ 0.05). ST resulted in significantly greater increases in limb girth than both CT1 and CON conditions (P = 0.05 and 0.004 respectively). CT3 induced significantly greater limb girth adaptations than CON condition (P = 0.04). No effect of time or intervention was observed for EMG (P > 0.05)" (Jones. 2013)
What remains to be seen, though is in how far a "saner" endurance training protocol would have produced a similarly pronounced negative effect on the training induced increases in limb girth (size) and strength (MVC), while still yielding at least some of the beneficial effects on time to exhaustion (TTE).
There may be something to higher volume for legs (learn more)
If this is not your first visit to the SuppVersity you may yet remember a couple of previous posts on leg training, all of which clearly suggested that the legs need to be hammered to grow. At first the results of the study at hand seem to contradict this assumption, but if we are honest, "a little more hammering" is not exactly doing 30 min of continuous leg extensions.
The latter takes us back to the previously mentioned methodological shortcomings of this study. In as much as the 30-min of 30% MVC leg extensions may be suitable to really isolate the muscle, they have little to nothing to do with the classic endurance protocols most people are thinking about, when the hear the term "concomitant training".
We do, on the other hand, know from previous studies, such as the Psilander study, I covered in some detail in a previous blogpost that additional cycling before a leg workout can potentially boost the growth response to a subsequent workout (learn more). Whether this means of training is sustainable over time, would obviously be a different question.
Bottom line: Due to the specific design of the "cardio" part of the study, and the exclusive focus on the quadriceps muscles, it is difficult to say something definitive about the practically more important question whether 30min of classic low to medium intensity cardio training (e.g. on a cycle ergometer) would actually hamper your gains in such a profound fashion - regardless of whether you perform it before or after your workout.
Effect of strength vs. endurance only vs. combined training on body fat loss and changes in VO2Max, power, strength and size; data expressed rel. to avg. effect sizes for each parameter (Wilson. 2012)
If I am yet looking back at the results Wilson et al. presented in their meta-review, it would seem that low-intensity, low frequency cardio training is not the no-go the study from the study at hand would suggest it was. HIIT training, obviously a whole different animal and not necessarily something you would want to perform after a strenuous leg workout, for example does provide an anabolic stimulus of its own (learn more). HIIT vs. steady state is yet only one of the any parameters that will ultimately determine, whether or not an additional aerobic component is going to hamper your strength performance. Another interesting observation Wilson et al. made was that the equipment the subjects used (and thus probably the effective metabolic demand) had an affect on the effectiveness of the strength training, as well.
Specifically, Wilson and his colleagues were able to show that the lack of weight support during treadmill running / jogging vs. cycling increased the detrimental effects on strength, power and size gains in the 21 studies the meta-analysis was based on. More than three cardio sessions per week, and high(er) intensity aerobic activity in general were likewise associated with practically relevant reductions in effect size.
On the other hand, some of these effects can be mitigated by doing cardio on separate days, so that you can still benefit from the concomittant (or endurance only) exclusive improvements in conditioning and avoid the VO2Max loss the scientists observed in the strength only groups. Skipping endurance work altogether is thus probably not the ideal method for the average physical culturist.
In the end, you will yet have to answer this question for yourself. Personally, I feel a baseline of 3x30min of various forms of "cardio" training (in the broadest sense) has always served me well.
References:
Jones TW, Howatson G, Russell M, French DN. Performance And Neuromuscular Adaptations Following Differing Ratios Of Concurrent Strength And Endurance Training. J Strength Cond Res. 2013 Mar 21.
Wilson JM, Marin PJ, Rhea MR, Wilson SM, Loenneke JP, Anderson JC. Concurrent training: a meta-analysis examining interference of aerobic and resistance exercises. J Strength Cond Res. 2012 Aug;26(8):2293-307.
