Effects of low-dose creatine monohydrate on muscle strength and endurance

Abstract

To investigate the effect of low-dose supplementation of creatine monohydrate without the use of the saturation phase, 36 male university students engaged in resistance training (age 22.5 ± 4.3 years, height 1.76 ± 0.08 m, weight 77.0 ± 11.0 kg, and body mass index 24.6 ± 2.5 kg/m2) were randomly divided into three groups: group placebo (GP), group supplemented with creatine 3 g/day (3G), and group supplemented with 5 g/day creatine (5G). The subjects were tested for maximum muscle strength (1RM), upper body muscle endurance (MPU), and abdominal muscle endurance (MSU) before and after 7, 14, 21, 28, and 35 days of creatine supplementation or placebo and performing standardized resistance training. After 35 days of supplementation and training, all groups showed a significant improvement in the 1RM test; however, the percentages of strength increase were significantly higher (P < 0.05) in the groups supplemented with creatine (G3, ∆% 1RM = 20.0 ± 4.0; G5, ∆% 1RM = 19.9 ± 1.5) than in the placebo group (GP, ∆% 1RM = 10.3 ± 1.9). Upper limb muscle endurance showed a significant improvement only in 5G, ranging from 39.9 ± 7.9 MPU/min to 50.7 ± 11.0 MPU/min after 35 days of supplementation. Interestingly, abdominal muscle endurance showed no increase in any of the groups (GP, P > 0.528; G3, P > 0.076; G5, P > 0.148). These results support a number of earlier studies that demonstrated that creatine supplementation at low doses and without the use of the loading phase are effective for increasing maximal strength and endurance of upper limbs.