We examined changes in muscle buffer capacity (beta m(in vitro)), VO2peak and the lactate threshold (LT) after 5 weeks of high-intensity interval training (INT) above the LT or moderate-intensity continuous training (CON) just below the LT. Prior to and immediately after training, 16 female subjects performed a graded exercise test to determine VO2peak and the LT, followed 2 days later by a resting muscle biopsy from the vastus lateralis muscle to determine beta m(in vitro). Following baseline testing, the subjects were randomly placed into the INT (n=8) or CON training group (n=8). Subjects then performed 5 weeks of cycle training (3 days per week), performing either high-intensity INT (6-10x2 min at 120-140\% LT with 1 min rest) or moderate-intensity CON (80-95\% LT) training. Total training volume was matched between the two groups. After the training period, both groups had significant improvements in VO2peak (12-14\%; P<0.05) and the LT (7-10\%; P<0.05), with no significant differences between groups. The INT group, however, had significantly greater improvements in beta m(in vitro) (25\%; 123+/-5-153+/-7 micromol H+ x g muscle dm(-1) x pH(-1); P<0.05) than the CON group (2\%; 130+/-12-133+/-7 micromol H+ x g muscle dm(-1) x pH(-1), P>0.05). Our results show that when matched for training volume, high-intensity interval training above the LT results in similar improvements in VO2peak and the LT, but greater improvements in beta m(in vitro) than moderate-intensity continuous training below the LT. This suggests that training intensity is an important determinant of changes to beta m(in vitro).

The effects of training intensity on muscle buffer capacity in females

BISHOP, DAVID JOHN;
2006-01-01

Abstract

We examined changes in muscle buffer capacity (beta m(in vitro)), VO2peak and the lactate threshold (LT) after 5 weeks of high-intensity interval training (INT) above the LT or moderate-intensity continuous training (CON) just below the LT. Prior to and immediately after training, 16 female subjects performed a graded exercise test to determine VO2peak and the LT, followed 2 days later by a resting muscle biopsy from the vastus lateralis muscle to determine beta m(in vitro). Following baseline testing, the subjects were randomly placed into the INT (n=8) or CON training group (n=8). Subjects then performed 5 weeks of cycle training (3 days per week), performing either high-intensity INT (6-10x2 min at 120-140\% LT with 1 min rest) or moderate-intensity CON (80-95\% LT) training. Total training volume was matched between the two groups. After the training period, both groups had significant improvements in VO2peak (12-14\%; P<0.05) and the LT (7-10\%; P<0.05), with no significant differences between groups. The INT group, however, had significantly greater improvements in beta m(in vitro) (25\%; 123+/-5-153+/-7 micromol H+ x g muscle dm(-1) x pH(-1); P<0.05) than the CON group (2\%; 130+/-12-133+/-7 micromol H+ x g muscle dm(-1) x pH(-1), P>0.05). Our results show that when matched for training volume, high-intensity interval training above the LT results in similar improvements in VO2peak and the LT, but greater improvements in beta m(in vitro) than moderate-intensity continuous training below the LT. This suggests that training intensity is an important determinant of changes to beta m(in vitro).
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11562/314901
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