Written by Anssi Manninen
05 March 2007
It's well established that serious athletes need more protein than sedentary people. However, it's unclear whether a very high protein intake offers advantages over a moderately high protein intake. So, a recent study at the College of New Jersey examined the effects of varying daily protein intakes on strength, body composition and endocrine changes (e.g., testosterone, cortisol, IGF-1) during a 12-week resistance-training program. In this study, 23 collegiate strength-power athletes were stratified into three separate categories of daily protein consumption: below recommended levels (1-1.4 grams/kilogram/day), recommended levels (1.6-1.8 grams/kilogram/day) and above recommended levels (more than 2 grams/kilogram/day).

Since the results indicated no statistically significant differences in strength, body composition or hormone levels between the groups, the authors concluded, "The results of this study do not provide support for protein intakes greater than recommended levels in collegiate strength/power athletes for body composition improvements or alterations in resting hormonal concentrations."

It should be noted, however, that lean body mass was increased by 1.1 ± 2.2 kilograms in a very high protein group and 0.8 ± 1.5 kilograms in a moderately high protein group, whereas no change was observed in a lower protein group. Furthermore, a 35 percent and 42 percent greater improvement in bench press maximum was seen by a very high protein group in comparison to a lower protein group and a moderately high protein group, respectively. Also, improvements in squat maximum were 63 percent and 22 percent greater for a very high protein group compared to a lower protein group and a moderately high protein group, respectively. Thus, it appears that a very high protein intake offers some advantages during resistance training.

 

Reference: Hoffman JR et al. Effect of protein intake on strength, body composition and endocrine changes in strength/power athletes. J Int Soc Sports Nutr, 3(2):12-18, 2006.