Investigating factors associated with variation of muscle hypertrophy response: focusing on protein intake

2022 Fiscal Year Final Research Report

• Project/Area Number: 20K23312
• Research Category: Grant-in-Aid for Research Activity Start-up
• Allocation Type: Multi-year Fund
• Review Section: 0909:Sports sciences, physical education, health sciences, and related fields
• Research Institution: National Agency for the Advancement of Sports and Health
• Principal Investigator: Yasuda Jun 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, スポーツメディカルセンター, 契約研究員 (90878224)
• Project Period (FY): 2020-09-11 – 2023-03-31
• Keywords: たんぱく質 / 筋肉 / 朝食 / レジスタンストレーニング

Outline of Final Research Achievements

This study investigated the relationship between muscle hypertrophy response and protein intake at breakfast in adult men and women undergoing resistance training (RT). The subjects were 31 healthy adult men and women (45% female). Subject characteristics, nutrient intake, and sleep and physical activity status were assessed using a wearable device. Biceps RT was performed twice a week for 12 weeks at 70% of maximal lifting weight. Muscle mass index was assessed as muscle cross-sectional area of the biceps brachii muscle using MRI technique. After 12 weeks of intervention, muscle hypertrophy was 14.2 ± 8.3% in the biceps brachii. Using multiple regression analysis and adjusting for the effects of confounding factors, only breakfast protein intake per kg body weight was significantly associated with muscle hypertrophy rate.

Free Research Field

栄養学

Academic Significance and Societal Importance of the Research Achievements

本研究によって、自由生活下における筋肥大の説明因子およびその貢献度が明らかになることで、今後の筋肥大に対する運動や栄養介入の効果の正確性および問題抽出に寄与できる。
そして、本研究は健康維持・向上に重要な筋肥大および汎用性の高い「食事」に着目している点から、幅広い集団に対して貢献可能なエビデンスになると期待される。