Faster Muscle Hypertrophy, Lower Visceral & Liver Fat, Trig & Glucose Levels W/ Fish vs. Casein | Plus: Shift From Slow to Fast Twitch Muscle Interesting for Strength Athletes

If casein protein is good for slow and fish protein is good for fast twitch muscle, "fish and cheese" would be the perfect muscle food, no? Read the whole article and find out if that's the case.

As a SuppVersity reader you've read about the "wonders" of fish protein before. If I am not completely mistaken, though, the study at hand which is about to be published in the peer-reviewed journal Bioscience, Biotechnology, and Biochemistry very soon, is the "fish protein study" with the most impressive results.

So impressive, in fact, that I am willing to write about it, although the study was conducted with "hairy" athletes aka rodents. So, let's not make it too exciting and start with the main results, right away: Fuminori Kawabata and his Japanese colleagues found that fish protein intake increases fast-twitch muscle weight, reduces liver triglycerides and serum glucose levels in rats, compared with a casein diet.

You can learn more about protein intake at the SuppVersity

Are You Protein Wheysting?

Cod protein for recovery

Salmon Hydro. > Whey?

High EAA protein for fat loss

Fast vs. slow protein

Phys. response to Cod protein

As you can see in Figure 1, the improvements in lipid management were significant specifically for the triglycerides in the blood and liver of the rodents who were fed iso-caloric diets containing either casein or fish protein for 8 weeks.

Figure 1: Changes in serum and liver lipids; * indicates statistical significance (Kawabata. 2014)

In view of the close relationship between triglyceride and glucose management (remember the TRIG has a carbohydrate backbone), it's not really surprising that there was a small, but statistically significant improved (=lower) glucose response to the oral glucose tolerance test, as well (see Figure 2).

Figure 2: Improved glucose clearance during oral glucose tolerance test at the end of the 8 week study period in the fish vs. casein protein groups (Kawabata. 2014)

If we look at the underlying mechanisms, we'd have to name the following findings as potential mechanistic causes of these effects:

• an increase in muscle mass in the fish vs. casein fed rodents (9.5% soleus muscle, 9.7% gastrocnemius, 10% extensor digitorum longus muscle)
• reductions in white fat (-3% total; -11% visceral) and non significant increases in brown fat (+1%)
• increases in muscle GLUT-4 expression (+39%)

With the latter, i.e. the upregulation of genes involved in the fast-twitch muscle and glucose uptake, probably being the most significant change in terms of blood glucose management.

Will you see the same results with eating fish? I doubt they will be identical to the consumption of faster-absorbing fish protein powders (which taste like crap, by the way), but the study at hand should certainly be an incentive to up your fish intake... you won't regret it, although it's not going to make you big and ripped instantaneously. Even if you're planning to have a baby, scientists from the University of Washington have calculated that the benefits in terms of reduced myocardial infarction risk outweigh any potential issues with increased mercury intake from fish (Ponce. 2000) | Learn more about the healthiest fish and "Make the Right Fish Choices"!

In addition, Kawabata et al. found that the consumption of fish vs. casein protein led to a small but significant relative increase of type II (fast twitch; resistance training; see Figure 3 at the bottom) vs. type I (slow twitch; endurance training) fibers:

"Since there were no reported protein sources that affect musclefiber-type changes, and overall, very few foods change muscle fiber type from slow to fast, the possibility of switch to fast-twitch muscle caused by fish protein observed in the present study is thought to be a significant phenomenon in thefield of skeletal muscle physiology." (Kawabata. 2014)

Now, the obvious question is: "We see changes, but what's so different about fish vs. sodium caseinate - is it the amino acid composition?

Table 1: Amino acid component and nutritional analysis of protein sources (Kawabata. 2014).

Table 1 shows the amino acid composition of the fish and casein protein that was added the rodent diets. Among the things that could maybe explain the differences are taurine (no taurine in casein, ~0.5% in fish protein), glycine (+2.4%), cystine (+0.7%), and arginine (+2.58%).

All of the aforementioned amino acids have previously been linked to improvement in blood glucose and / or blood lipid management, but it's hard to believe that the small inter-protein differences could explain the significant differences.

Furthermore, casein protein contains a higher amount of BCAAs which would stand in contrast to its inferior muscle building effects in the non-exercised Sprague Dawley rats in the study at hand.

Figure 3: The effect offish protein on myosin heavy chain gene expressions in the soleus and extensor digitorum longus muscles

Bottom line: I am afraid, I cannot tell you why fish protein favors type II muscle growth. What I can tell you, though, is that this is not the first study to observe that fish vs. casein protein leads to increased muscle gains in type II muscle fibers. The fact that the inter-group differences in this study compared to a previous 4 weeks study by Mizushige et al. were significantly more pronounced do also suggest that the beneficial effects of fish protein on skeletal muscle weight are enhanced by extending the fish protein feeding period (Mizushige. 2010).

A possible explanation for the general increase in fiber size would be a reduction in atrophy-related ubiquitin ligases the scientists observed in the study at hand.

The general change from fat utilization (lipoprotein lipase, an enzyme that breaks down triglycerides, was sign. reduced in the fish oil group) to carbohydrate utilization (GLUT-4 & co were increasd), on the other hand, could explain the improvements in glucose management and reductions in triglycerides. Still, "[f]urther investigations are needed to elucidate whether fish protein intake shifts muscle fiber type from slow to fast." Comment on Facebook!

References:

• Kawabata, Fuminori, et al. "Fish protein intake induces fast-muscle hypertrophy and reduces liver lipids and serum glucose levels in rats." Bioscience, biotechnology, and biochemistry ahead-of-print (2014): 1-8. 
• Mizushige, Takafumi, et al. "Fast-twitch muscle hypertrophy partly induces lipid accumulation inhibition with Alaska pollack protein intake in rats." Biomedical Research 31.6 (2010): 347-352.
• Ponce, Rafael A., et al. "Use of Quality‐Adjusted Life Year Weights with Dose‐Response Models for Public Health Decisions: A Case Study of the Risks and Benefits of Fish Consumption." Risk Analysis 20.4 (2000): 529-542.

Revisiting Caffeine + Lactate - In Combination They May be Powerful Muscle Builders Which Boost Satellite Cell Activity + Anabolic Signalling And Trigger Muscle Hypertrophy

High intensity training builds muscle and maximizes lactate build up. Caffeine helps you to train at maximal intensities. Correct, but there appears to be a more direct link between lactate accumulation, caffeine supplementation and skeletal muscle hypertrophy.

No, you are not mistaken: The headline says and means that caffeine and lactate are powerful agents that may promote skeletal muscle hypertrophy by boosting satellite cell activity and anabolic signalling in favor of muscle hypertrophy.

After a thorough review of the existing literature discussing the individual effects of caffeine and lactate on skeletal muscle metabolism and anabolism, Yoshimi Oishi and colleagues from the Ritsumeikan University hypothesized that "a lactate-based supplement containing caffeine, an activator of intracellular calcium signals, could elicit proliferation and differentiation of satellite cells, activate anabolic signals in skeletal muscle, and thereby increase muscle mass when combined with low-intensity exercise training."

Are you looking for other muscle building tips?

Tri- or Multi-Set Training for Body Recomp.?

Alternating Squat & Blood Pressure - Productive?

Pre-Exhaustion Exhausts Your Growth Potential

Full ROM ➯ Full Gains - Form Counts!

Battle the Rope to Get Ripped & Strong

Study Indicates Cut the Volume Make the Gains!

Well, you already know that they were able to proof their hypothesis, right? Let's still take a look at how they did that - at least briefly:

"To assess this hypothesis, we initially examined whether lactate and/or lactate-caffeine treatment could elicit proliferation and differentiation of satellite cells or activate anabolic signals in C2C12 skeletal muscle cells. Furthermore, we examined whether the administration of a mixed lactate and caffeine compound (LC compound), concomitant with endurance exercise training, could effectively increase muscle mass via activated satellite cells and/or anabolic signals in rat skeletal muscle" (Oishi. 2015)

I know, the human study is missing, but if you think about the intensity dependent increase in lactate production it appears logical to assume that increasing lactate levels which as previously been shown to...

• upregulate the expression of MCT1 and genes coding for other components of the mitochondrial reticulum in skeletal muscle (Brooks. 2009)
• increase myogenin (the satellite cell activator) mRNA in skeletal muscle cells in the petri dish (Hashimoto. 2007)

Now, this raises the question how calcium comes into play. According to Oishi et al. its beneficial effects are related the ability of caffeine supplements to increase the amount of intracellular calcium (Lu. 2007), which activates calcineurin, which will in turn induce slow and fast fiber hypertrophy (Talmadge. 2008) - unfortunately, this effect appears to favor type I (=endurance fiber) over type II hypetrophy, but this may well depend on the trigger that's used, i.e. endurance training as it was the case in a rodent study by Talmadge et al. or your strength workouts.

Figure 1: Graphical illustration of the mechanism by which caffeine and lactate may increase your gains.

Too complicated? Well, check out my graphical summary in Figure 1. I guess this should explain the basic mechanism: Lactate up = increase satellite cell proliferation = hotbed for muscle hypertrophy + calcium up = increased calcineurin = trigger for increased hypertrophy.

Bicarbonate supplementation buffers the decline in muscle pH and allows for 15% greater increases in lactate levels while still increasing training performance on a high volume, high intensity leg workout | read more

High intensity = high lactate, high intensity + bicarbonate = even higher lactate: The study at hand used lactate + caffeine supplementation and low intensity exercise. With high intensity exercise the increase the usefulness of additional lactate supplements may be significantly reduced, because higher intensity equals higher lactate accumulation anyway. As a previously discussed study on high intensity high volume leg training indicates, this effect can be augmented by sodium bicarbonate supplementation which allows for increased lactate levels in the absence of the debilitating effects of skeletal muscle acidosis (read more).

In the study at hand, the researchers quantified the effects on skeletal muscle hypertrophy by weighing the gastrocnemius and tibialis muscle of the rodents after 4 weeks of treadmill training and the effects on muscle restructuring via incorporation of new muscle nuclei (learn more) by measuring the increase in DNA content from exercise training alone and exercise training in conjunction with lactate + caffeine supplementation.

Figure 2: Exercise and exercise + supplementation induced changes in muscle weight and DNA content of skeletal muscle in mice exposed to four weeks of low intensity treadmill running (Oishi. 2015).

As the data in Figure 2 indicates, both muscle hypertrophy and the exercise induced increase in satellite cell activity were further augmented by the addition of lactate and caffeine in dosages of 1g/kg sodium-lactate and 36mg/kg caffeine.

In conjunction with the likewise observed increases in myogenin and follistatin expression of the fast twitch (that's what you use for lifting weights) gastrocnemius muscle relative to the exercise alone, the results of the study at hand clearly warrant the scientists conclusion that the administration of sodium lactate and caffeine "can effectively increase muscle mass concomitant with elevated numbers of myonuclei, even with low-intensity exercise training, via activated satellite cells and anabolicsignals" (Oishi. 2015).

So, what does this mean in practice? Assuming the same effects would occur in human beings the effective dosages of sodium lactate and caffeine would be 81mg/kg and 2.9mg/kg, respectively. Practically speaking you would have to take ~6.5g of sodium lactate and 232mg of caffeine.

Remember? Study suggests, significant increases in mitochondrial builder PGC1-a with HIIT + sodium bicarbonate | read more

That's quite a reasonable amount and should not have nasty side effects. Whether the sodium lactate offers additional benefits to trainees who work out far beyond the lactate threshold (remember: the rodents did only "light exercise"), remains questionable. The same goes for the question whether the addition of sodium bicarbonate would elicit similar beneficial effects on the lactate induced increase in satellite activity. In view of the fact that previous studies show that it does potentiate the beneficial effects on another albeit not directly related marker of mitochondrial changes in muscle structure, namely PGC-alpha (see previous SuppVersity article), I personally believe this would be worth investigating | Comment on Facebook!

References:

• Brooks, George A. "Cell–cell and intracellular lactate shuttles." The Journal of physiology 587.23 (2009): 5591-5600.
• Hashimoto, Takeshi, et al. "Lactate sensitive transcription factor network in L6 cells: activation of MCT1 and mitochondrial biogenesis." The FASEB Journal 21.10 (2007): 2602-2612.
• Lu, Ying-Mei, et al. "Imbalance between CaM kinase II and calcineurin activities impairs caffeine-induced calcium release in hypertrophic cardiomyocytes." Biochemical pharmacology 74.12 (2007): 1727-1737. 
• Oishi, Yoshimi, et al. "Mixed lactate and caffeine compound increases satellite cell activity and anabolic signals for muscle hypertrophy." Journal of Applied Physiology (2015): jap-00054.
• Talmadge, Robert J., et al. "Calcineurin activation influences muscle phenotype in a muscle-specific fashion." BMC cell biology 5.1 (2004): 28.