Effect of two different creatine supplementation products on muscular strength and power

Abstract

To compare different types of creatine supplements on indices of strength and endurance, 48 males (22.3 ± 0.6 y) participated in a 21d study. Subjects consumed creatine in a powder (CRp), in a solid form of gelled candy (CRs) or a carbohydrate placebo was taken in a solid, gelled candy (PLBs) or in powder form (PLBp). All supplements and placebo were fed in a double blind regime at a dose of 20 g/day for 5 days followed by lOg/day for 16 days. Pre‐testing on day 1 included body composition (hydrostatic weighing) and 5, 10‐s sprints on a Monark cycle ergometer. Subjects pedaled against an opposing force of 0.834 N per kg body mass (0.085 kp • kg−1) with a 40‐s rest between each sprint (SPR). On day 2, subjects performed a 1 repetition maximum (1RM) lift on a leg press and 5 sets of 30 maximal voluntary contractions (total = extension + flexion) on a Kin Com Isokinetic Dynamometer at 180°/s with a 45‐s rest between each bout. Statistical analysis showed that CRp and CRs group supplementation resulted in a significant increase in group mean total body weight (1.5 ±0.2 and 1.6 ±0.3 kg), respectively and fat free mass (FFM) (2.3 ± 0.5 and 2.7 ± 0.6 kg), respectively. PLBp resulted in a group mean increase in FFM (1.3 ± 0.6 kg) but not in body weight (0.6 ± 0.3 kg). There was no change in the PLBs group mean weight (0.1 ± 0.3 kg) or FFM (0.1 ± 0.3 kg). Supplementation for 21 d resulted in a significant increase in the 1RM of the leg press for CRp (63.1 ± 6.7 kg), and CRs (52.9 ± 11.9 kg). There was no change in the group mean 1RM for each of the placebo groups (PLBp: 32.3 ± 12.4 kg; PLBs: 30.6 ± 6.7 kg). The peak power and fatigue index were not significantly different between groups in the post anaerobic sprints, however, mean power output was higher in CRp and CRs compared with PLBs and PLBp. Isokinetic tests revealed no significant difference in total peak torque among the four groups as a result of supplementation. Total work was significantly greater in CRs and CRp compared with PLBc. There was no difference in CRp, CRs and PLBp. The percent decline in force were significantly lower in CRs and CRp compared with PLBp and PLBs, indicating less fatigue during the 30 contractions. These results indicate that subjects supplemented with CR whether in powder or solid form showed a significantly greater gain in FFM and indices of strength compared with subjects fed a placebo.