Creatine-dextrose and protein-dextrose induce similar strength gains during training

Background: Creatine supplementation during resistance exercise training ha s been reported to induce greater increases in fat-free mass (FFM). muscle fiber area, and strength when compared with a placebo. We have recently sho wn that timing of nutrient delivery in the postexercise period can have pos itive effects on whole boby protein turnover (B. D, Roy et al.. Med Sti Spo rts Exerc. 32(8):1412-1418. 2000).Purpose: We tested the hypothesis that a postexercise protein-carbohydrate supplement would result in similar increa ses in FFM. muscle fiber area. and strength us compared with creatine monoh ydrate (CM). during a supervised 2-month resistance exercise training progr am in untrained men. Methods: Young healthy male subjects were randomized t o receive either CM and glucose (N = 11: CM 10 g + glucose 75 g [CR-CHO] (C ELL-Tech((R)))) or protein and glucose (N = 8: casein 10 g + glucose 75 g [ CRO+CHO], using double-blinded allocation, Participants performed 8 wk of w hole body split-routine straight set weight training, 1 h.d(-1), 6 d.wk(-1) . Measurements. pre-and post-training were made of fat-free mass (FFM: DEXA ), total bode mass, muscle fiber area, isokinetic knee extension strength ( 45 and 240 degrees .s(-1)), and 1 repetition maximal ( I RM) strength for 1 6 weight training exercises. Results: Total body mass increased more for CR -CHO (+ 4.3 kg, 5.4%) as compared with PRO-CHO (+ 1.9 kg. 2.4%) (P < 0.05 f or interaction) and FFM increased after training, (P < 0.01) but was not si gnificantly different between the groups (CR-CHO = +4.0 kg 6.4%: PRO-CHO = +2.6 kg.4.1%) (P = 0.11 for interaction). Muscle fiber area increased simil arly after training for both groups 20%: P < 0.05), Training resulted in an increase in IRM for each of the 16 activities (range = 14.2-39.9%) (P < 0. 001), isokinetic knee extension torque (P < 0.01). with no treatment effect s upon any of the variables. Conclusions: we concluded that postexercise su pplementation with PRO-CHO resulted in similar increases in strength after a resistance exercise training program as compared with CR-CHO. However. th e greater gains in total mass for the CR-CHO group may have implications fo r sport-specific performance.