Long-term creatine intake is beneficial to muscle performance during resistance training

Abstract

The effects of oral creatine supplementation on muscle phosphocreatine (PCr) concentration, muscle strength, and body composition were investigated in young female volunteers (n = 19) during 10 wk of resistance training (3 h/wk). Compared with placebo, 4 days of high-dose creatine intake (20 g/day) increased (P < 0.05) muscle PCr concentration by 6%. Thereafter, this increase was maintained during 10 wk of training associated with low-dose creatine intake (5 g/day). Compared with placebo, maximal strength of the muscle groups trained, maximal intermittent exercise capacity of the arm flexors, and fat-free mass were increased 20-25, 10-25, and 60% more (P < 0. 05), respectively, during creatine supplementation. Muscle PCr and strength, intermittent exercise capacity, and fat-free mass subsequently remained at a higher level in the creatine group than in the placebo group during 10 wk of detraining while low-dose creatine was continued. Finally, on cessation of creatine intake, muscle PCr in the creatine group returned to normal within 4 wk. It is concluded that long-term creatine supplementation enhances the progress of muscle strength during resistance training in sedentary females.

Influence of creatine supplementation on 800 m wheelchair performance: a pilot study

“…Most studies investigated the influence of creatine supplementation on leg muscle performance. [1][2][3][4][5][6]8,9,16,[24][25][26] Since arm muscles contain more type II fibres than leg muscles and since type II fibres have initially a higher phosphocreatine content than type I fibres, 15 it could be hypothesised that creatine supplementation would be less efficient for arm exercise, an assumption that is supported by our findings. However, this hypotesis has to be investigated in further studies, as one cannot conclude definitely if an initially higher phosphocreatine content of arm muscles limits the effectiveness of a creatine supplementation in this muscle group.…”

“…16,[22][23][24][25][26] Interestingly, in most of the studies showing no ergogenic effect on exercise performance after creatine supplementation, a time or distance trial was performed, [22][23][24][25][26] whereas in studies with a positive effect the time to exhaustion at a given workload was determined. 3,8,9,21 This type of exercise test depends mainly on metabolism and remaining energy stores, whereas during time trials higher movement frequencies are required to improve test results. This is also a neuromuscular problem that not only depends on energy sources.…”

“…1,7,23,30 Interestingly, one study with women only found a small, nonsignificant increase in body mass compared to placebo. 31 This could possibly be due to their smaller muscle mass. This assumption is supported by other investigations in older men, where only a small or no increase in body mass was reported after creatine supplementation.…”

“…[1][2][3][4][5][6][7][8][9] In general, enhanced performance was found in repetitive, high-intensity, short-term exercise tasks. Furthermore, creatine was successfully used also in patients with chronic heart failure, mitochondrial cytopathies and neuromuscular disease.…”

Protective effects of oral creatine supplementation on spinal cord injury in rats

“…From human studies it is known that with a relatively high dosage of creatine (20 grams of creatine monohydrate per day for an adult person of approximately 70 kg, given in intervals of 465 grams) the maximal level of creatine is increased by 10 ± 15% depending on the individual, with the pool being saturated after 7 ± 10 days. 29 Following this loading phase, the maximal pool size can be maintained by a lower maintenance dosage of 2 ± 5 grams per day. It has been shown in rat and other animal species that a creatine supplementation period of 2 ± 4 weeks at the dosage used in this study is necessary and su cient to signi®cantly augment the creatine pool to its maximal size.…”