We investigated the effects of high-intensity intermittent cross-training(HIICT)on maximal oxygen uptake(VO_(2)max).The HIICT consisted of alternating intermittent 20-s treadmill running(1^(st),3^(rd),5^(th),and 7^(th...We investigated the effects of high-intensity intermittent cross-training(HIICT)on maximal oxygen uptake(VO_(2)max).The HIICT consisted of alternating intermittent 20-s treadmill running(1^(st),3^(rd),5^(th),and 7^(th) bouts)and 20-s bicycle exercise(2^(nd),4^(th),and 6^(th) bouts)with a 10-s rest period.Each intensity for running and bicycling of the HIICT corresponded to an oxygen demand of~160% and~170%of the VO_(2)max,respectively.Fifteen healthy young males(aged[24±1]yrs)were randomly assigned to training(TG,n?8)and non-training control(CG,n?7)groups.The TG completed this HIICT daily 4 days/week for 6 weeks.Significant group×time interactions were observed for both the running and bicycling VO_(2)max(p<0.001 each).After the training,the VO_(2)max for both running([57.4±4.8]mL·kg^(-1)·min^(-1))and bicycling([50.6±3.7]mL·kg^(-1)·min^(-1))in the TG were significantly higher than those for running([50.1±3.1]mL·kg^(-1)·min^(-1))and bicycling([43.7±3.6]mL·kg^(-1)·min^(-1))in the CG,respectively(p<0.01 each).Post-hoc tests revealed a significant increase in VO_(2)max for running and bicycling in the TG after the HIICT(p<0.001 each)but no significant difference in the CG.These results demonstrated that the newly developed HIICT increases the VO_(2)max for both running and bicycling.展开更多
Oxygen uptake(V O_(2))was measured during a non-exhaustive high-intensity intermittent cross-exercise(HIICE)protocol consisting of four alternating bouts of 20 s running(R)and three bouts of bicycle exercise(BE)at~160...Oxygen uptake(V O_(2))was measured during a non-exhaustive high-intensity intermittent cross-exercise(HIICE)protocol consisting of four alternating bouts of 20 s running(R)and three bouts of bicycle exercise(BE)at~160%and~170%maximal oxygen uptake(V O_(2)max),respectively,with 10 s between-bout rests(sequence R-BE-R-BER-BE-R).The V O_(2) during the last BE([52.2±5.0]mL⋅kg^(-1)⋅min^(-1))was significantly higher than the V O_(2)max of the BE([48.0±5.4]mL⋅kg^(-1)⋅min^(-1),n=30)and similar to that of running.For clarifying the underlying mechanisms,a corresponding HIICE-protocol with BE and arm cranking ergometer exercise(AC)was used(sequence AC-AC-BE-AC-BE-AC-AC-BE).In some experiments,thigh blood flow was occluded by a cuff around the upper thigh.Without occlusion,the V O_(2) during the AC([39.2±7.1]mL⋅kg^(-1)⋅min^(-1)[6th bout])was significantly higher than the V O_(2)max of AC([30.2±4.4]mL⋅kg^(-1)⋅min^(-1),n=7).With occlusion,the corresponding V O_(2)([29.8±3.9]mL⋅kg^(-1)⋅min^(-1))was reduced to that of the V O_(2)max of AC and significantly less than the V O_(2) without occlusion.These findings suggest that during the last bouts of HIICE may exceed the of the specific exercise,probably because it is a summation of the V O_(2) for the ongoing exercise plus excess post-oxygen consumption(EPOC)produced by the previous exercise with a higher V O_(2)max.展开更多
基金supported in part by a Grant-in-Aid for Scientific Research(C)(no.24K14417)from the Japan Society for the Promotion of Sciences(JSPS)KAKENHI.
文摘We investigated the effects of high-intensity intermittent cross-training(HIICT)on maximal oxygen uptake(VO_(2)max).The HIICT consisted of alternating intermittent 20-s treadmill running(1^(st),3^(rd),5^(th),and 7^(th) bouts)and 20-s bicycle exercise(2^(nd),4^(th),and 6^(th) bouts)with a 10-s rest period.Each intensity for running and bicycling of the HIICT corresponded to an oxygen demand of~160% and~170%of the VO_(2)max,respectively.Fifteen healthy young males(aged[24±1]yrs)were randomly assigned to training(TG,n?8)and non-training control(CG,n?7)groups.The TG completed this HIICT daily 4 days/week for 6 weeks.Significant group×time interactions were observed for both the running and bicycling VO_(2)max(p<0.001 each).After the training,the VO_(2)max for both running([57.4±4.8]mL·kg^(-1)·min^(-1))and bicycling([50.6±3.7]mL·kg^(-1)·min^(-1))in the TG were significantly higher than those for running([50.1±3.1]mL·kg^(-1)·min^(-1))and bicycling([43.7±3.6]mL·kg^(-1)·min^(-1))in the CG,respectively(p<0.01 each).Post-hoc tests revealed a significant increase in VO_(2)max for running and bicycling in the TG after the HIICT(p<0.001 each)but no significant difference in the CG.These results demonstrated that the newly developed HIICT increases the VO_(2)max for both running and bicycling.
基金supported in part by a KAKENHI Grant-in-Aid for Challenging Exploratory Research 26560406 from the Japan Society for the Promotion of Sciences.
文摘Oxygen uptake(V O_(2))was measured during a non-exhaustive high-intensity intermittent cross-exercise(HIICE)protocol consisting of four alternating bouts of 20 s running(R)and three bouts of bicycle exercise(BE)at~160%and~170%maximal oxygen uptake(V O_(2)max),respectively,with 10 s between-bout rests(sequence R-BE-R-BER-BE-R).The V O_(2) during the last BE([52.2±5.0]mL⋅kg^(-1)⋅min^(-1))was significantly higher than the V O_(2)max of the BE([48.0±5.4]mL⋅kg^(-1)⋅min^(-1),n=30)and similar to that of running.For clarifying the underlying mechanisms,a corresponding HIICE-protocol with BE and arm cranking ergometer exercise(AC)was used(sequence AC-AC-BE-AC-BE-AC-AC-BE).In some experiments,thigh blood flow was occluded by a cuff around the upper thigh.Without occlusion,the V O_(2) during the AC([39.2±7.1]mL⋅kg^(-1)⋅min^(-1)[6th bout])was significantly higher than the V O_(2)max of AC([30.2±4.4]mL⋅kg^(-1)⋅min^(-1),n=7).With occlusion,the corresponding V O_(2)([29.8±3.9]mL⋅kg^(-1)⋅min^(-1))was reduced to that of the V O_(2)max of AC and significantly less than the V O_(2) without occlusion.These findings suggest that during the last bouts of HIICE may exceed the of the specific exercise,probably because it is a summation of the V O_(2) for the ongoing exercise plus excess post-oxygen consumption(EPOC)produced by the previous exercise with a higher V O_(2)max.
