TY - JOUR
T1 - Adverse effects of energy restriction on myogenic enzymes in judoists
AU - Umeda, Takashi
AU - Nakaji, Shigeyuki
AU - Shimoyama, Tadashi
AU - Yamamoto, Youske
AU - Totsuka, Manabu
AU - Sugawara, Kazuo
PY - 2004/4
Y1 - 2004/4
N2 - In this study, we examined the effects of weight reduction by restricting energy intake on muscle function and serum concentrations of myogenic enzymes in judoists. Twenty-seven male judoists aged 19.3 ± 0.6 years (mean±s) were divided into three groups based on the extent of body weight reduction: high weight reduction (height 1.70 ± 0.05 m, body mass 78.5 ± 13.6 kg), low weight reduction (height 1.70 ± 0.05 m, body mass 80.7 ± 13.1 kg) and a group that maintained body weight while continuing to perform exercise training (height 1.78 ± 0.07 m, body mass 78.7 ± 8.8 kg). Body composition, blood biochemistry, energy intake and anaerobic power were assessed on four occasions: 20 days (baseline data), 4 days and 1 day before and 7 days after competition. Compared with baseline, body mass and fat-free mass were significantly lower 1 day before competition in the high and low weight reduction groups (both P < 0.01); these changes persisted for 7 days after competition in the high weight reduction group. Serum creatine kinase was significantly elevated 1 day before competition in all groups (all P <0.05), and remained higher 7 days after competition in both the high and low weight reduction groups. Compared with baseline, maximal anaerobic power was significantly lower 1 day before competition only in the high weight reduction group (P < 0.01). Our results suggest that energy restriction in addition to intense exercise training before major competition has an adverse effect on anaerobic power and elevates serum creatine kinase concentration, leading to an impairment of muscular function and an increased susceptibility of muscle tissue to injury.
AB - In this study, we examined the effects of weight reduction by restricting energy intake on muscle function and serum concentrations of myogenic enzymes in judoists. Twenty-seven male judoists aged 19.3 ± 0.6 years (mean±s) were divided into three groups based on the extent of body weight reduction: high weight reduction (height 1.70 ± 0.05 m, body mass 78.5 ± 13.6 kg), low weight reduction (height 1.70 ± 0.05 m, body mass 80.7 ± 13.1 kg) and a group that maintained body weight while continuing to perform exercise training (height 1.78 ± 0.07 m, body mass 78.7 ± 8.8 kg). Body composition, blood biochemistry, energy intake and anaerobic power were assessed on four occasions: 20 days (baseline data), 4 days and 1 day before and 7 days after competition. Compared with baseline, body mass and fat-free mass were significantly lower 1 day before competition in the high and low weight reduction groups (both P < 0.01); these changes persisted for 7 days after competition in the high weight reduction group. Serum creatine kinase was significantly elevated 1 day before competition in all groups (all P <0.05), and remained higher 7 days after competition in both the high and low weight reduction groups. Compared with baseline, maximal anaerobic power was significantly lower 1 day before competition only in the high weight reduction group (P < 0.01). Our results suggest that energy restriction in addition to intense exercise training before major competition has an adverse effect on anaerobic power and elevates serum creatine kinase concentration, leading to an impairment of muscular function and an increased susceptibility of muscle tissue to injury.
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U2 - 10.1080/0264041031000140446
DO - 10.1080/0264041031000140446
M3 - Article
C2 - 15161106
AN - SCOPUS:1842688069
SN - 0264-0414
VL - 22
SP - 329
EP - 338
JO - Journal of Sports Sciences
JF - Journal of Sports Sciences
IS - 4
ER -