N Yuza1, K Ishida, M Miyamura. 1. Junior College Division of Chukyo Women's University, Obu, Aichi, Japan. yuza@chujo-u.ac.jp
Abstract
BACKGROUND: To clarify 1) how the cross-transfer effect, obtained in a contralateral untrained forearm through a 4-week ipsilateral endurance training regimen, is changed during detraining; and 2) how blood flow to the untrained limb is related to the transfer effect of muscular endurance during training and detraining periods. METHODS: Training regimen: hand-grip training by means of a hand-ergometer with a work-load of 1/3 of the maximum handgrip strength 5 times a week for 4 weeks. Blood flow: a mercury-in-rubber strain-gauge for venous occlusion plethysmography. MEASURES: 1) maximal number of contractions to determine the muscular endurance; 2) reactive hyperaemic blood flow response (RHBF3) to determine whether maximal vasodilatory capacity would be changed in both the forearms post-training and detraining; and 3) maximal work-related blood flow. RESULTS: We found significant increments both in the muscle endurance and the maximal work-related blood flow not only in the trained (+125%, +30%) but also in the untrained (+40%, +19%) forearms. During detraining, we found decreases both in the muscle endurance and the maximal work-related blood flow (-22%, p<0.01; -16%, p=0.053) of the trained forearm. However, in the untrained arm (-3%, NS) the cross-transfer effect of muscular endurance remained unchanged despite a drop in the maximal work-related blood flow (-17%, p<0.05). The RHBF3 did not change in either of the forearms during the whole periods. CONCLUSIONS: These findings suggest that the maintenance of the cross transfer effect of muscle endurance during detraining cannot be explained on the basis of changes in forearm blood flow.
BACKGROUND: To clarify 1) how the cross-transfer effect, obtained in a contralateral untrained forearm through a 4-week ipsilateral endurance training regimen, is changed during detraining; and 2) how blood flow to the untrained limb is related to the transfer effect of muscular endurance during training and detraining periods. METHODS: Training regimen: hand-grip training by means of a hand-ergometer with a work-load of 1/3 of the maximum handgrip strength 5 times a week for 4 weeks. Blood flow: a mercury-in-rubber strain-gauge for venous occlusion plethysmography. MEASURES: 1) maximal number of contractions to determine the muscular endurance; 2) reactive hyperaemic blood flow response (RHBF3) to determine whether maximal vasodilatory capacity would be changed in both the forearms post-training and detraining; and 3) maximal work-related blood flow. RESULTS: We found significant increments both in the muscle endurance and the maximal work-related blood flow not only in the trained (+125%, +30%) but also in the untrained (+40%, +19%) forearms. During detraining, we found decreases both in the muscle endurance and the maximal work-related blood flow (-22%, p<0.01; -16%, p=0.053) of the trained forearm. However, in the untrained arm (-3%, NS) the cross-transfer effect of muscular endurance remained unchanged despite a drop in the maximal work-related blood flow (-17%, p<0.05). The RHBF3 did not change in either of the forearms during the whole periods. CONCLUSIONS: These findings suggest that the maintenance of the cross transfer effect of muscle endurance during detraining cannot be explained on the basis of changes in forearm blood flow.
Authors: Lars L Andersen; Christoffer H Andersen; Jørgen H Skotte; Charlotte Suetta; Karen Søgaard; Bengt Saltin; Gisela Sjøgaard Journal: Biomed Res Int Date: 2014-02-23 Impact factor: 3.411