Effects of rapid weight loss on body water and electrolyte control, and oxidative stress for weight class athletes

2019 Fiscal Year Final Research Report

• Project/Area Number: 16K21685
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Sports science; Developmental mechanisms and the body works
• Research Institution: National Agency for the Advancement of Sports and Health
• Principal Investigator: Nishimaki Mio 独立行政法人日本スポーツ振興センター国立スポーツ科学センター, スポーツ科学部, 契約職員 (20757538)
• Project Period (FY): 2016-04-01 – 2020-03-31
• Keywords: 減量 / 脱水 / 酸化ストレス / 減量期間

Outline of Final Research Achievements

Many reports have been published on the negative health effects of rapid weight loss (RWL) in　wrestlers. This study aim was the effects of different periods of RWL on dehydration state and oxidative stress.Participants were nine male collegiate wrestlers who reduce their body mass by 5% within short period in randomized order using the same methods. They have experienced 1-day, 3-days and 7-days) weight loss separated by more than 4 weeks. All participants reduced 5% of their body mass in all trials. Following the weight loss, they tried to regain all of their lost weight with an ad libitum diet for 14 h. Body composition and biochemical variables were measured at baseline and immediately after weight loss and weight regain.For plasma aldosterone concentrations and plasma d-ROMs concentrations, two-way analysis of variance revealed the main effect of time (p<0.05). RWL is surmised to have increased oxidative stress via dehydration and elevated levels of aldosterone.

Free Research Field

スポーツ医学

Academic Significance and Societal Importance of the Research Achievements

急速減量は極端な食事摂取制限により身体を負のエネルギーバランスにならないよう恒常性を保つ．成人であっても急速減量は脱水，低血糖，体温調節機能低下，免疫機能低下などを引き起こすが，成長期ではさらに大きな影響が予想される。成長期にある高校生年代は骨格や筋肉の発達途上にあり、負のエネルギーバランスの状態は発育・発達やホルモンバランスの乱れにつながる．成長期における急速減量は一時的なパフォーマンスだけでなく，骨格や筋肉の発達を阻害し，その後の長期的なパフォーマンスにまで影響する可能性がある．本研究の発展に伴い減量の方法に関する年代別及び性別の基準を設定することが可能になる．