In other articles we've discussed how pre-and post-exercise consumption of whey protein hydrolysate combined with carbohydrate helps to optimise glycogen levels as part of endurance exercise1, 2. The studies cited in these articles involved the one-off use of whey protein hydrolysate and carbs. But this model of consumption does not exemplify how the average endurance athlete uses protein supplements.
Long-Term Benefits of Whey Protein Hydrolysate
Most athletes purchase a tub of protein, which with regular use might last them a month or so. So an important question to pose is what benefits are there (if any) from regular use of whey protein hydrolysates combined with carbohydrate over one-off use. For instance does the regular consumption of whey protein hydrolysate and carbs lead to improvements in the way an endurance athlete stores and utilises glycogen? Or in more general terms, can regular consumption of whey protein hydrolysate and carbs lead to improvements in endurance?
Effects of Whey Protein Hydrolysate on Endurance and Glycogen
These are questions that researchers from Japan were hoping to answer when they took a group of mice and divided them in four groups: sedentary, sedentary with whey protein hydrolysate, exercise and exercise with whey protein hydrolysate. Mice in the exercise groups performed treadmill running five times per week for 4 weeks3. Quite funny when one tries to picture it. As part of the study, scientists profiled the expression of key proteins involved in endurance and glycogen synthesis, while also measuring endurance performance and the glycogen content of the gastrocnemius muscle3.
Improved Endurance and Glycogen Synthesis Confirmed by Protein Expression
After the training period, the endurance of mice fed the whey protein hydrolysate diet was improved compared with that of mice fed the control diet. In addition, as expected, weekly endurance training resulted in a significant increase in muscle glycogen content in both exercising groups. However, the group ingesting whey protein hydrolysate had a further increase in glycogen. In terms of the possible modifications in protein synthesis underlying the observed changes, the researchers were able to show that only the whey protein hydrolysate plus exercise group exhibited altered expression patterns for three proteins. The researchers concluded that these three proteins may be potential biomarkers of improved endurance and glycogen resynthesis and part of the mechanism that mediates the benefits of whey protein hydrolysate consumption on endurance exercise performance3.
Regular Use of Whey Protein Hydrolysate for Endurance Athletes
While this study was only performed in mice, the findings are hard to ignore and it’s not unreasonable to expect that similar findings would result in humans. As is the nature with science and research, it will probably only be a short while until a study like this is replicated in humans. Until such time, however, on the weight of current evidence, it is still reasonable to advise endurance athletes to consume whey protein hydrolysate as a regular part of their training regime. The studies cited in this short series together with existing research on the use of whey protein hydrolysate in strength athletes provide a sound scientific platform for its regular use by endurance athletes to improve performance.
1. Morifuji M, et al. Post-exercise carbohydrate plus whey protein hydrolysates supplementation increases skeletal muscle glycogen level in rats. Amino Acids. 2010;38(4):1109-1115.
2. Morifuji M, et al. Preexercise ingestion of carbohydrate plus whey protein hydrolysates attenuates skeletal muscle glycogen depletion during exercise in rats. Nutrition. 2011;27(7-8):833-837.
3. Aoi W, et al. Dietary whey hydrolysate with exercise alters the plasma protein profile: A comprehensive protein analysis. Nutrition. 2011;27(6):687-692.