Background:The benefits associated with sports compression garments are thought to be closely related to enhanced blood flow.However,findings are equivocal,possibly due to heterogeneity in the techniques used for meas...Background:The benefits associated with sports compression garments are thought to be closely related to enhanced blood flow.However,findings are equivocal,possibly due to heterogeneity in the techniques used for measuring blood flow,the garment types used,and the pressures applied.This study combined Doppler ultrasound and near-infrared spectroscopy technologies to provide the first comprehensive assessment of the effects of 3 sports compression garment types on markers of venous return and muscle blood flow at rest.Methods:Resting lower-limb blood flow measures(markers of venous return,muscle blood flow,and muscle oxygenation)of 22 elite,junior,male basketball players(age=17.2±0.9 years,mean±SD)were assessed in 4 separate conditions:no compression(CON),compression tights(TIGHTS),compression shorts(SHORTS),and compression socks(SOCKS).Markers of venous return(cross-sectional area,time-averaged mean and peak blood flow velocity,and venous blood flow)were measured via Doppler ultrasound at the popliteal and common femoral veins.Muscle blood flow and muscle oxygenation were measured in the gastrocnemius medialis and vastus lateralis using near-infrared spectroscopy.Results:Popliteal markers of venous return were higher in TIGHTS compared to CON(p<0.01)and SHORTS(p<0.01),with SOCKS values higher compared with CON(p<0.05).Common femoral vein markers of venous return were higher for all conditions compared to CON(p<0.05),with TIGHTS values also higher compared to SOCKS(p<0.05).Gastrocnemius medialis blood flow was higher for TIGHTS compared to CON(p=0.000),SOCKS(p=0.012),and SHORTS(p=0.000),with SOCKS higher compared to SHORTS(p=0.046).Vastus lateralis blood flow was higher for TIGHTS compared to CON(p=0.028)and SOCKS(p=0.019),with SHORTS also higher compared to CON(p=0.012)and SOCKS(p=0.005).Gastrocnemius medialis oxygenation was higher for TIGHTS compared to CON(p=0.003),SOCKS(p=0.033),and SHORTS(p=0.003),with SOCKS higher compared to CON(p=0.044)and SHORTS(p=0.032).Vastus lateralis oxygenation was higher for TIGHTS compared to CON(p=0.020)and SOCKS(p=0.006).Conclusion:Markers of venous return,muscle blood flow,and muscle oxygenation are increased with sports compression garments.TIGHTS are most effective,potentially because of the larger body area compressed.展开更多
Purpose:We aimed to perform a systematic review and meta-analysis of the effects of training to muscle failure or non-failure on muscular strength and hypertrophy.Methods:Meta-analyses of effect sizes(ESs)explored the...Purpose:We aimed to perform a systematic review and meta-analysis of the effects of training to muscle failure or non-failure on muscular strength and hypertrophy.Methods:Meta-analyses of effect sizes(ESs)explored the effects of training to failure vs.non-failure on strength and hypertrophy.Subgroup meta-analyses explored potential moderating effects of variables such as training status(trained vs.untrained),training volume(volume equated vs.volume non-equated),body region(upper vs.lower),exercise selection(multi-vs.single-joint exercises(only for strength)),and study design(independent vs.dependent groups).Results:Fifteen studies were included in the review.All studies included young adults as participants.Meta-analysis indicated no significant difference between the training conditions for muscular strength(ES=-0.09,95%confidence interval(95%CI):-0.22 to 0.05)and for hypertrophy(ES=0.22,95%CI:-0.11 to 0.55).Subgroup analyses that stratified the studies according to body region,exercise selection,or study design showed no significant differences between training conditions.In studies that did not equate training volume between the groups,the analysis showed significant favoring of non-failure training on strength gains(ES=-0.32,95%CI:-0.57 to-0.07).In the subgroup analysis for resistance-trained individuals,the analysis showed a significant effect of training to failure for muscle hypertrophy(ES=0.15,95%CI:0.03-0.26).Conclusion:Training to muscle failure does not seem to be required for gains in strength and muscle size.However,training in this manner does not seem to have detrimental effects on these adaptations,either.More studies should be conducted among older adults and highly trained individuals to improve the generalizability of these findings.展开更多
Objectives:Adolescents using active transport(AT)to school have higher levels of physical activity(PA)compared with motorized transport(MT)users.This study compared school day and weekend day PA in adolescents using A...Objectives:Adolescents using active transport(AT)to school have higher levels of physical activity(PA)compared with motorized transport(MT)users.This study compared school day and weekend day PA in adolescents using AT,MT,or combined AT and MT(AT + MT)to travel to school.Methods:Adolescents(n= 314;age:14.7±1.4 years;32.8% boys)from Dunedin(New Zealand)wore an accelerometer for 7 days and completed a self-reported survey regarding mode of transport to school(73 AT,56 AT + MT,and 185 MT).Data were analyzed using t tests,analysis of variance,and χ2 tests.Results:Although the proportion of adolescents meeting PA guidelines significantly differed among transport groups(AT,47.9%;AT + MT,46.4%;MT,33.5%;p=0.048;overall,39.2%),the observed differences were due mainly to girls.Compared with MT,AT and AT+MT engaged in more moderate-to-vigorous PA(MVPA)per day(AT:61.2 ± 23.2 min;AT+MT:59.6 ± 21.7 min;MT:52.5 ± 19.6 min;p = 0.004;p<0.001,adjusted for gender),per school day and before school.Immediately after school(15:00-16:00),AT engaged in significantly more MVPA compared with AT + MT and MT.No differences in MVPA between the groups were observed in the late afternoon/early evening period during school days or on weekend days.Conclusion:Compared with MT users,adolescent girls using AT or AT + MT accumulated more MVPA during school commute time.AT + MT to school is also a plausible way to increase adolescent girls’ PA when AT only is not feasible.展开更多
Objective:In this review,we critically evaluate studies directly comparing the effects of plyometric vs.resistance training on skeletal muscle hypertrophy.Methods:We conducted electronic searches of PubMed/MEDLINE,Sco...Objective:In this review,we critically evaluate studies directly comparing the effects of plyometric vs.resistance training on skeletal muscle hypertrophy.Methods:We conducted electronic searches of PubMed/MEDLINE,Scopus,SPORTDiscus,and Web of Science to find studies that explored the effects of plyometric vs.resistance training on muscle hypertrophy.Results:Eight relevant studies were included in the review.Six studies compared the effects of plyometric vs.resistance training on muscle hypertrophy,while 2 studies explored the effects of combining plyometric and resistance training vs.isolated resistance training on acute anabolic signaling or muscle hypertrophy.Based on the results of these studies,we conclude that plyometric and resistance training may produce similar effects on whole muscle hypertrophy for the muscle groups of the lower extremities.Therefore,it seems that plyometric training has a greater potential for inducing increases in muscle size than previously thought.Despite the findings observed at the whole muscle level,the evidence for the effects of plyometric training on hypertrophy on the muscle fiber level is currently limited for drawing inferences.Compared to isolated resistance training,combining plyometric and resistance exercise does not seem to produce additive effects on anabolic signaling or muscle growth;however,this area requires future study.The limitations of the current body of evidence are that the findings are specific to(a)musculature of the lower extremities,(b)short-term training interventions that lasted up to 12 weeks,and(c)previously untrained or recreationally active participants.Conclusion:This review highlights that plyometric and resistance training interventions may produce similar effects on whole muscle hypertrophy,at least for the muscle groups of the lower extremities,in untrained and recreationally trained individuals,and over short-term(i.e.,≤12 weeks)intervention periods.展开更多
Purpose:This review aimed to synthesize previous findings on the test-retest reliability of the 30-15 Intermittent Fitness Test(IFT).Methods:The literature searches were performed in 8 databases.Studies that examined ...Purpose:This review aimed to synthesize previous findings on the test-retest reliability of the 30-15 Intermittent Fitness Test(IFT).Methods:The literature searches were performed in 8 databases.Studies that examined the test-retest reliability of the 30-15 IFT and presented the intraclass correlation coefficient(ICC) and/or the coefficient of variation(CV) for maximal velocity and/or peak heart rate were included.The consensus-based standards for the selection of health measurement instruments(COSMIN) checklist was used for the assessment of the methodological quality of the included studies.Results:Seven studies,with a total of 10 study groups,explored reliability of maximal velocity assessed by the 30-15 IFT.ICCs ranged from0.80 to 0.99,where 70% of ICCs were≥0.90.CVs for maximal velocity ranged from 1.5% to 6.0%.Six studies,with a total of 7 study groups,explored reliability of peak heart rate as assessed by the 30-15 IFT.ICCs ranged from 0.90 to 0.97(i.e.,all ICCs were≥0.90).CVs ranged from 0.6% to 4.8%.All included studies were of excellent methodological quality.Conclusion:From the results of this systematic review,it can be concluded that the 30-15 IFT has excellent test-retest reliability for both maximal velocity and peak heart rate.The test may,therefore,be used as a reliable measure of fitness in research and sports practice.展开更多
文摘Background:The benefits associated with sports compression garments are thought to be closely related to enhanced blood flow.However,findings are equivocal,possibly due to heterogeneity in the techniques used for measuring blood flow,the garment types used,and the pressures applied.This study combined Doppler ultrasound and near-infrared spectroscopy technologies to provide the first comprehensive assessment of the effects of 3 sports compression garment types on markers of venous return and muscle blood flow at rest.Methods:Resting lower-limb blood flow measures(markers of venous return,muscle blood flow,and muscle oxygenation)of 22 elite,junior,male basketball players(age=17.2±0.9 years,mean±SD)were assessed in 4 separate conditions:no compression(CON),compression tights(TIGHTS),compression shorts(SHORTS),and compression socks(SOCKS).Markers of venous return(cross-sectional area,time-averaged mean and peak blood flow velocity,and venous blood flow)were measured via Doppler ultrasound at the popliteal and common femoral veins.Muscle blood flow and muscle oxygenation were measured in the gastrocnemius medialis and vastus lateralis using near-infrared spectroscopy.Results:Popliteal markers of venous return were higher in TIGHTS compared to CON(p<0.01)and SHORTS(p<0.01),with SOCKS values higher compared with CON(p<0.05).Common femoral vein markers of venous return were higher for all conditions compared to CON(p<0.05),with TIGHTS values also higher compared to SOCKS(p<0.05).Gastrocnemius medialis blood flow was higher for TIGHTS compared to CON(p=0.000),SOCKS(p=0.012),and SHORTS(p=0.000),with SOCKS higher compared to SHORTS(p=0.046).Vastus lateralis blood flow was higher for TIGHTS compared to CON(p=0.028)and SOCKS(p=0.019),with SHORTS also higher compared to CON(p=0.012)and SOCKS(p=0.005).Gastrocnemius medialis oxygenation was higher for TIGHTS compared to CON(p=0.003),SOCKS(p=0.033),and SHORTS(p=0.003),with SOCKS higher compared to CON(p=0.044)and SHORTS(p=0.032).Vastus lateralis oxygenation was higher for TIGHTS compared to CON(p=0.020)and SOCKS(p=0.006).Conclusion:Markers of venous return,muscle blood flow,and muscle oxygenation are increased with sports compression garments.TIGHTS are most effective,potentially because of the larger body area compressed.
文摘Purpose:We aimed to perform a systematic review and meta-analysis of the effects of training to muscle failure or non-failure on muscular strength and hypertrophy.Methods:Meta-analyses of effect sizes(ESs)explored the effects of training to failure vs.non-failure on strength and hypertrophy.Subgroup meta-analyses explored potential moderating effects of variables such as training status(trained vs.untrained),training volume(volume equated vs.volume non-equated),body region(upper vs.lower),exercise selection(multi-vs.single-joint exercises(only for strength)),and study design(independent vs.dependent groups).Results:Fifteen studies were included in the review.All studies included young adults as participants.Meta-analysis indicated no significant difference between the training conditions for muscular strength(ES=-0.09,95%confidence interval(95%CI):-0.22 to 0.05)and for hypertrophy(ES=0.22,95%CI:-0.11 to 0.55).Subgroup analyses that stratified the studies according to body region,exercise selection,or study design showed no significant differences between training conditions.In studies that did not equate training volume between the groups,the analysis showed significant favoring of non-failure training on strength gains(ES=-0.32,95%CI:-0.57 to-0.07).In the subgroup analysis for resistance-trained individuals,the analysis showed a significant effect of training to failure for muscle hypertrophy(ES=0.15,95%CI:0.03-0.26).Conclusion:Training to muscle failure does not seem to be required for gains in strength and muscle size.However,training in this manner does not seem to have detrimental effects on these adaptations,either.More studies should be conducted among older adults and highly trained individuals to improve the generalizability of these findings.
基金supported by the Health Research Council of New Zealand Emerging Researcher First Grant (14/565)National Heart Foundation of New Zealand(1602 and 1615)+2 种基金Lottery Health Research Grant (Applic 341129)University of Otago Research Grant (UORG 2014)Dunedin City Council and internal grants from the School of Physical Education,Sport and Exercise Sciences,University of Otago
文摘Objectives:Adolescents using active transport(AT)to school have higher levels of physical activity(PA)compared with motorized transport(MT)users.This study compared school day and weekend day PA in adolescents using AT,MT,or combined AT and MT(AT + MT)to travel to school.Methods:Adolescents(n= 314;age:14.7±1.4 years;32.8% boys)from Dunedin(New Zealand)wore an accelerometer for 7 days and completed a self-reported survey regarding mode of transport to school(73 AT,56 AT + MT,and 185 MT).Data were analyzed using t tests,analysis of variance,and χ2 tests.Results:Although the proportion of adolescents meeting PA guidelines significantly differed among transport groups(AT,47.9%;AT + MT,46.4%;MT,33.5%;p=0.048;overall,39.2%),the observed differences were due mainly to girls.Compared with MT,AT and AT+MT engaged in more moderate-to-vigorous PA(MVPA)per day(AT:61.2 ± 23.2 min;AT+MT:59.6 ± 21.7 min;MT:52.5 ± 19.6 min;p = 0.004;p<0.001,adjusted for gender),per school day and before school.Immediately after school(15:00-16:00),AT engaged in significantly more MVPA compared with AT + MT and MT.No differences in MVPA between the groups were observed in the late afternoon/early evening period during school days or on weekend days.Conclusion:Compared with MT users,adolescent girls using AT or AT + MT accumulated more MVPA during school commute time.AT + MT to school is also a plausible way to increase adolescent girls’ PA when AT only is not feasible.
文摘Objective:In this review,we critically evaluate studies directly comparing the effects of plyometric vs.resistance training on skeletal muscle hypertrophy.Methods:We conducted electronic searches of PubMed/MEDLINE,Scopus,SPORTDiscus,and Web of Science to find studies that explored the effects of plyometric vs.resistance training on muscle hypertrophy.Results:Eight relevant studies were included in the review.Six studies compared the effects of plyometric vs.resistance training on muscle hypertrophy,while 2 studies explored the effects of combining plyometric and resistance training vs.isolated resistance training on acute anabolic signaling or muscle hypertrophy.Based on the results of these studies,we conclude that plyometric and resistance training may produce similar effects on whole muscle hypertrophy for the muscle groups of the lower extremities.Therefore,it seems that plyometric training has a greater potential for inducing increases in muscle size than previously thought.Despite the findings observed at the whole muscle level,the evidence for the effects of plyometric training on hypertrophy on the muscle fiber level is currently limited for drawing inferences.Compared to isolated resistance training,combining plyometric and resistance exercise does not seem to produce additive effects on anabolic signaling or muscle growth;however,this area requires future study.The limitations of the current body of evidence are that the findings are specific to(a)musculature of the lower extremities,(b)short-term training interventions that lasted up to 12 weeks,and(c)previously untrained or recreationally active participants.Conclusion:This review highlights that plyometric and resistance training interventions may produce similar effects on whole muscle hypertrophy,at least for the muscle groups of the lower extremities,in untrained and recreationally trained individuals,and over short-term(i.e.,≤12 weeks)intervention periods.
文摘Purpose:This review aimed to synthesize previous findings on the test-retest reliability of the 30-15 Intermittent Fitness Test(IFT).Methods:The literature searches were performed in 8 databases.Studies that examined the test-retest reliability of the 30-15 IFT and presented the intraclass correlation coefficient(ICC) and/or the coefficient of variation(CV) for maximal velocity and/or peak heart rate were included.The consensus-based standards for the selection of health measurement instruments(COSMIN) checklist was used for the assessment of the methodological quality of the included studies.Results:Seven studies,with a total of 10 study groups,explored reliability of maximal velocity assessed by the 30-15 IFT.ICCs ranged from0.80 to 0.99,where 70% of ICCs were≥0.90.CVs for maximal velocity ranged from 1.5% to 6.0%.Six studies,with a total of 7 study groups,explored reliability of peak heart rate as assessed by the 30-15 IFT.ICCs ranged from 0.90 to 0.97(i.e.,all ICCs were≥0.90).CVs ranged from 0.6% to 4.8%.All included studies were of excellent methodological quality.Conclusion:From the results of this systematic review,it can be concluded that the 30-15 IFT has excellent test-retest reliability for both maximal velocity and peak heart rate.The test may,therefore,be used as a reliable measure of fitness in research and sports practice.
