Effect of resistance exercise with slow movement, and elucidation of the mechanism

2006 Fiscal Year Final Research Report Summary

• Project/Area Number: 17300202
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Sports science
• Research Institution: University of Thukuba
• Principal Investigator: TAKAMATSU Kaoru University of Thukuba, Graduate school of comprehensive human sciences, Professor, 大学院人間総合科学研究科, 教授 (90015727)
• Co-Investigator(Kenkyū-buntansha): ISHII Naokata University of Tokyo, Department of life Sciences, Professor, 大学院総合文化研究科, 教授 (20151326) ; KIZUKA Tomohiro University of Thukuba, Graduate school of comprehensive human sciences, Associate Professor, 大学院人間総合科学研究科, 助教授 (30323281)
• Project Period (FY): 2005 – 2006
• Keywords: resistance exercise / slow lift / noradrenaline / free testosterone

Research Abstract

This study examined the effects of different exercise duration of concentric and eccentric actions during resistance exercise with slow movement on hormonal responses. Nine adult men performed following four trials on separate days.
・Low-intensity resistance exercise with slow movement (5s for lifting action, 1 s for lowering action; 5-1 trial)
・Low-intensity resistance exercise with slow movement (Is for lifting action, 5 s for lowering action, 1-5 trial)
・Low-intensity resistance exercise with slow movement (3s for lifting action, 3 s for lowering action, 3-3 trial)
High-intensity resistance exercise with normal movement (Is for lifting action, Is for lowering action, 1-1 trial)
Resistance exercise consisted of 4 sets of bilateral knee extension. Blood samples were collected to determine blood hormone concentrations. Oxygen uptake and heart rate were also measured during each set of exercise and rest periods between sets.
The results showed that total work volume throughout four sets of exercise was significantly greater in the 1-1 trial than other three trials. Among the trials using slow lifting, 1-5 trial showed a highest work volume, with significant difference between 1-5 and 5-1 trials. Blood lactate concentration after exercise showed significantly greater values in the 1-1 and 5-1 trials than in the 1-5 trial No significant difference was observed in the exercise-induced increases in hormone concentrations among the trials, but 1-5 trial showed smaller responses of noradrenalin and free testosterone. In addition, 1-1 and 5-1 trials showed greater values of oxygen uptake and heart rate. The exercise-induced strength loss showed no significant difference among the trials.
These results indicate that slow-lifting exercise with longer duration of concentric phase augments exercise-induced metabolic stress. Alternatively, the exercise with longer duration of eccentric phase shows smaller secretions of noradrenalin and free testosterone, and respiratory responses.