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