Discussion
a reduced number, muscle soreness, fatigue
The main finding of the present study was that protein supplementation––whether administered before sleep or earlier in the day––does not seem to induce beneficial effects on markers of recovery, body composition, or performance compared to an isoenergetic carbohydrate placebo during a short-term period of strenuous training loads in professional cyclists who naturally consume a high-protein diet (>2.5 g/kg/day on average in our participants), as previously documented and corroborated here [The acute increase in training loads usually imposed by strenuous situations such as training camps or multistage races represents a physiological challenge for endurance athletes. In this effect, training loads increased approximately two-fold during the six-day training camp compared with the preceding month, which resulted in an increased perceived fatigue, muscle soreness, and a reduced performance in all the study participants. In this effect, protein supplementation might potentially help to accelerate muscle remodeling and recovery during strenuous training [Some evidence supports a beneficial effect of protein supplementation in situations of strenuous endurance training. Huang et al. [Another major finding of the present study was the lack of beneficial effects of pre-sleep protein supplementation when compared not only with the same protein supplement provided earlier in the day but also with an isoenergetic non-protein placebo. Pre-sleep protein supplementation has received attention in recent years due to its potential to enhance recovery and promote training-induced adaptations [One of the factors that could explain the lack of benefits observed with protein supplementation in the present study is the high daily protein intake of cyclists––Some limitations of the present study should be acknowledged. We analyzed a reduced number of participants due to the inherent difficulties of conducting research with high-performance athletes such as those assessed here. Moreover, we used a parallel-group design, but a crossover design could have reduced the potential confounding effect of between-individual variability. Some of the outcome assessment methods used here could also be optimized. Notably, nutritional intake was registered with a self-reported food diary, and we did not use more accurate indicators of body compositions such as dual-energy X-ray absorptiometry. On the other hand, the high protein intake of the participants might have confounded our results, and it is possible to hypothesize that protein supplementation could have been beneficial if dietary protein intake had been restricted (