Muscle Strength and Energetics at Baseline and Changes on Study.

Data are mean (SD). The mean differences and the 95% confidence intervals between treatment groups of the changes from baseline at weeks 2 and 14 were determined by unpaired t-tests. Asterisks (*) are used to indicate within-group changes from baseline that are statistically significant by paired t-test (P<0.05).
Strength was measured as the 1 repetition maximum (1RM) for each muscle group (in pounds) except for the rectus abdominus, in which strength was assessed as the number of sit-ups completed in 30 seconds; and maximum voluntary contraction (MVC, in Newtons) of the tibialis anterior muscle, which was assessed during dorsiflexion of the right foot. Muscle function was evaluated using two exercise protocols that were performed inside a 1.9T magnet. The first protocol consisted of a 15-second maximum voluntary contraction (MVC) that was used to assess the rate of PCr recovery (an index of oxidative capacity). The second protocol consisted of 36 consecutive MVCs, one every 10 seconds, with cycles of 6 seconds of contraction and 4 seconds of relaxation. This latter protocol was used to assess muscle fatigue.
Abbreviations: Rep, Repetitions; PCr, phosphocreatine; Pi, inorganic phosphate; PCr recovery (t ½), time needed to recover half of the baseline PCr value.