Oxygen uptake during the last bouts of exercise incorporated into high-intensity intermittent cross-exercise exceeds the V_ O2max of the same exercise mode

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.

Effects of 3 months of full-court and half-court street basketball training on health profile in untrained men

Purpose: The aim of the present study was to investigate whether street basketball organized as 3 v 3 on either a half court(HC) with 1 basket or a full court(FC) with 2 baskets could improve fitness and health profiles of untrained men after 3 months of supervised training.Methods: Thirty-five untrained men(aged 20—42 years) completed the pre-and post-intervention testing(FC: n = 13, HC: n = 12, CO(control):n = 10). The training attendance was 2.0 ± 0.4 and 1.9 ± 0.3 times per week in FC and HC, respectively. Mean heart rate(HR) was 83.8 ± 6.0 percent of maximal heart rate(%HR_(max)) and 84.5 ± 2.9 %HR_(max) in FC and HC, respectively.Results: The 3 months of street basketball training on an FC with 2 baskets increased maximal oxygen uptake(2.4 mL/min/kg(95% confidence interval(CI): 1.0—3.9)), time to exhaustion(47 s(95%CI: 26—67)), lean body mass(0.8 kg(95%CI: 0.1—1.5)), and bone mineral density(0.021 g/cm^2(95%CI: 0.011—0.031)), whereas mean arterial pressure(—5.6 mm Hg(95%CI: —7.5 to 3.7)), body fat percentage(—1.6%,(95%CI: —2.5 to —0.7)), heart rate(—18 bpm(95%CI: —24 to —12)), and blood lactate(median: —1.4 mmol/L(interquartile range: —1.5 to —0.6)) during submaximal running were lowered. The changes were less pronounced after the training period when playing on an HC with 1 basket, but increases in maximal oxygen uptake(1.6 mL/min/kg(95%CI: —0.1 to 3.3)), time to exhaustion(28 s(95%CI: 9—47)), lean body mass(1.3 kg(95%CI: 0.3—2.4)), and lower body fat percentage(—0.9%(95%CI: —1.9 to —0.1)) were observed in this group.Conclusion: Three months of 3 v 3 street basketball training improved fitness and led to broad-spectrum improvements in variables related to overall health profile, with the most marked effects observed when playing on an FC with 2 baskets.

Somatotype Components, Aerobic Fitness and Grip Strength in Kuwaiti Males and Females

Introduction and Objective: We investigated the association of endo-, meso- and ecto-morphic components of somatotype with aerobic power, mid-trunk flexibility and grip strength. Methods: Healthy male (n = 226) and female (n = 86) subjects, aged 9 - 55 years, sedentary (n = 154) or participating in sports (n = 158) were studied. Anthro-pometrics (height, weight, 8 skin folds, arm and calf circumferences, elbow and knee diameters), maximal exercise O2 uptake, mid trunk flexibility, right and left grip strength were measured. Results: Sedentary adult females were endomorphic with mesomorph tendency, and had low aerobic power (27.8 ± 0.6 ml/Kg·min) and low (48.7 ± 1 Kg) grip strength. Sedentary males (young and adults) and Sports adult males were mesomorph with endomorphic tendency. Sports junior males were balanced mesomorph. Aerobic power was 54.1 ± 0.9 ml/Kg·min in sports young males, 53.8 ± 0.9 ml/Kg·min in sports adult males, 41.2 ± 4.3 ml/Kg·min in sedentary young males, and 39.5 ± 1 ml/Kg·min in sedentary adult males. Grip strength was 89.9 ± 1.7 Kg in sports adult males, 86.7 ± 2 Kg in sedentary adult males, 75.6 ± 2.2 Kg in sports junior males and 52 ± 9.1 Kg in young sedentary males. Step-wise multiple regression analysis of somatotype components on aerobic power revealed dominant negative contribution (P < 0.001) of endomorphy (r2 = 0.57, 57%), and small but significant positive contributions of mesomorphy (0.6%) and ectomorphy (0.6%): Aerobic power = [56.1 - 4.3 (endomorphy) + (mesomorphy) + 1.4 (ectomorphy)] ± 9.1 SEE. Height and somatotype components accounted for 69% of the variance (R2) in grip strength;height had greatest contribution (60%): Grip Strength = [1.7 (Height) - 6.5 (ectomorphy) - 3.4 (endomorphy) - 2 (mesomorphy) - 200] ± 12.9 SEE. Measured variables accounted for <2% of flexibility variance. Conclusion: Endomorphy contributes greatly and negatively to variance in aerobic power. Body height was the anthropometric variable with the greatest positive association with the variance in grip strength. Flexibility appears to be unrelated to somatotype components.

Dietary Supplement with a Combination of Rhodiola Crenulata and Ginkgo Biloba Enhances the Endurance Performance in Healthy Volunteers

Objective:To determine whether the ingestion of a herbal supplement called Rhodiola-Gingko Capsule(RGC) would enhance the endurance performance of healthy volunteers and change relevant hormones in a favorable manner.Methods:Seventy healthy male volunteers(age ranges from 18 to 22 years old) were randomly assigned to RGC group(35 cases,each capsule containing 270 mg herbal extracts,4 capsules per day) or placebo group(35 cases,equivalent placebo preparation) for 7 weeks using computerproduced digital random...

The Road to the Beijing Winter Olympics and Beyond: Opinions and Perspectives on Physiology and Innovation in Winter Sport

Beijing will host the 2022 Winter Olympics,and China strengthens research on various aspects to allow their athletes to compete successfully in winter sport.Simultaneously,Government-directed initiatives aim to increase public participation in recreational winter sport.These parallel developments allow research to advance knowledge and understanding of the physiological determinants of performance and health related to winter sport.Winter sport athletes often conduct a substan-tial amount of training with high volumes of low-to-moderate exercise intensity and lower volumes of high-intensity work.Moreover,much of the training occur at low ambient temperatures and winter sport athletes have high risk of developing asthma or asthma-related conditions,such as exercise-induced bronchoconstriction.The high training volumes require optimal nutrition with increased energy and dietary protein requirement to stimulate muscle protein synthesis response in the post-exercise period.Whether higher protein intake is required in the cold should be investigated.Cross-country ski-ing is performed mostly in Northern hemisphere with a strong cultural heritage and sporting tradition.It is expected that innovative initiatives on recruitment and training during the next few years will target to enhance performance of Chinese athletes in classical endurance-based winter sport.The innovation potential coupled with resourcing and population may be substantial with the potential for China to become a significant winter sport nation.This paper discusses the physiological aspects of endurance training and performance in winter sport highlighting areas where innovation may advance in athletic performance in cold environments.In addition,to ensure sustainable development of snow sport,a quality ski patrol and rescue system is recommended for the safety of increasing mass participation.

High intensity interval training and molecular adaptive response of skeletal muscle

Increased cardiovascular fitness,VO_(2max),is associated with enhanced endurance capacity and a decreased rate of mortality.High intensity interval training(HIIT)is one of the best methods to increase VO_(2max)and endurance capacity for top athletes and for the general public as well.Because of the high intensity of this type of training,the adaptive response is not restricted to Type I fibers,as found for moderate intensity exercise of long duration.Even with a short exercise duration,HIIT can induce activation of AMPK,PGC-1α,SIRT1 and ROS pathway as well as by the modulation of Ca^(2+)homeostasis,leading to enhanced mitochondrial biogenesis,and angiogenesis.The present review summarizes the current knowledge of the adaptive response of HIIT.

Is BMI Associated with Cardiorespiratory Fitness?A Cross-Sectional Analysis Among 8470 Apparently Healthy Subjects Aged 18-94 Years from the Low-Lands Fitness Registry

Objective The purpose of the present study was to investigate the association between cardiorespiratory fitness(CRF)measured as peak oxygen uptake(VO_(2peak),expressed in mL/min)and body mass index(BMI)in a large cohort of apparently healthy subjects.Methods BMI and VO_(2peak)were measured in a cross-sectional study of 8470 apparently healthy adults.VO_(2peak)(mL/min)was determined by an incremental cycle ergometer test to exhaustion.Linear regression analyses were performed to identify predictors of CRF.Results There was no difference in CRF between adults with a normal weight(BMI between 18.5-24.9 kg/m^(2))and those who were overweight(BMI 25.0-29.9 kg/m^(2)).Subjects who were underweight(BMI<18.5 kg/m^(2))as well as females who were obese(BMI≥30.0 kg/m^(2))showed a reduced CRF compared to the normal and overweight groups.Age,height,and gender were significant predictors of CRF(R^(2)=0.467,P<0.0001);BMI did not add significantly to this relationship.Conclusion Our findings indicate that BMI was not associated with CRF in addition to age,height,and gender.In subjects with a BMI<18.5 kg/m^(2),CRF was lower compared to subjects with a BMI between 18.5 and 29.9 kg/m^(2).In obese subjects,CRF was only lower in females compared to females with a BMI between 18.5 and 29.9 kg/m^(2).Correcting CRF for BMI may be beneficial for subjects with a low BMI,and females with a BMI≥30.0 kg/m^(2).The outcome of this study might help to improve the interpretation of exercise testing results in individuals with a low or high BMI.