Consuming a protein supplement, specifically protein hydrolysate, during carbohydrate-restricted training was helpful for improving training intensity in women, but not in men, researchers have stated recently. The findings were part of a presentation at The Physiological Society’s Annual Conference Physiology 2021 last month.

Most nutrition guidelines for athletes are based on research in men only, said the authors. The study, by Dr Tanja Oosthuyse and her colleagues, emphasises that this shouldn’t be the case, because nutritional research findings in men don’t always apply to women, said Dr Oosthuyse.

While the protein supplement helped training intensity in women, it did not improve training intensity and instead resulted in a modest negative effect in men. It made exercise feel harder for them because their bodies were working harder to break down the supplement, as compared to when they were drinking just plain water. The conclusion from the research is that women should ingest protein supplements during fasted carbohydrate-restricted exercise, while men should be aware that it will increase their perception of effort.

Future studies need to determine whether ingesting protein hydrolysate supplements during carbohydrate-restricted training over a longer time frame of weeks or months will be beneficial, added the authors. In this study, the researchers did not consider menstrual phase. Follow-up studies are needed to determine whether the improved training intensity when ingesting a protein hydrolysate compared with placebo-water is specific to menstrual phase, they said.

Commenting on the study, Dr Oosthuyse said: “The application of the findings from our study are purely for the specialised training tactic of overnight fasted carbohydrate-restricted exercise, which is done to enhance training.
“Racing nutrition, however, is very different and at the moment, guidelines are standard for both men and women. We need to specify potential differences so that both men and women can train and race at the highest possible calibre.”