Effects of music and video on perceived exertion during high-intensity exercise

Background: Dissociative attentional stimuli(e.g., music, video) are effective in decreasing ratings of perceived exertion(RPE) during low-tomoderate intensity exercise, but have inconsistent results during exercise at higher intensity. The purpose of this study was to assess attentional focus and RPE during high-intensity exercise as a function of being exposed to music, video, both(music and video), or a no-treatment control condition.Methods: During the first session, healthy men(n = 15) completed a maximal fitness test to determine the workload necessary for high-intensity exercise(operationalized as 125% ventilatory threshold) to be performed during subsequent sessions. On 4 subsequent days, they completed 20 min of high-intensity exercise in a no-treatment control condition or while listening to music, watching a video, or both. Attentional focus, RPE,heart rate, and distance covered were measured every 4 min during the exercise.Results: Music and video in combination resulted in significantly lower RPE across time(partial η~2= 0.36) and the size of the effect increased over time(partial η~2= 0.14). Additionally, music and video in combination resulted in a significantly more dissociative focus than the other conditions(partial η~2= 0.29).Conclusion: Music and video in combination may result in lower perceived exertion during high-intensity exercise when compared to music or video in isolation. Future research will be necessary to test if reductions in perceived exertion in response to dissociative attentional stimuli have implications for exercise adherence.

Effects of different flui replacements on serum HSP70 and lymphocyte DNA damage in college athletes during exercise at high ambient temperatures

Purpose：The aim of this study was to investigate the effects of flui replacement by water or sports drinks on serum heat shock protein 70（HSP70） levels and DNA damage during exercise at a high ambient temperature.Methods：Ten male college athletes with an athletic career ranging from 6 to 11 years were recruited from Yonsei University.The subjects ran on a treadmill at 75% of heart rate reserve during 4 different trials：thermoneutral temperature at 18℃（T）,high ambient temperature at 32℃ without flui replacement（H）,high ambient temperature at 32℃ with water replacement（HW）,and high ambient temperature at 32℃ with sports drink replacement（HS）.During each condition,blood samples were collected at the pre-exercise baseline（PEB）,immediately after exercise（IAE）,and60 min post-exercise.Results：Skin temperature significant y increased during exercise and was significant y higher in H compared to T and HS at IAE.Meanwhile,serum HSP70 was significant y increased in all conditions at IAE compared to PEB and was higher in H compared to T at the former time point.Significant y increased lymphocyte DNA damage（DNA in the tail,tail length,tail moment） was observed in all trials at IAE compared to PEB,and attenuated DNA damage（tail moment） was observed in HS compared to H at IAE.Conclusion：Acute exercise elevates serum HSP70 and induces lymphocyte DNA damage.Fluid replacement by sports drink during exercise at high ambient temperature can attenuate HSP response and DNA damage by preventing dehydration and reducing thermal stress.

Influence of cardiorespiratory fitness and body composition on resting and post-exercise indices of vascular health in young adults

Poor cardiorespiratory fitness may mediate vascular impairments at rest and following an acute bout of exercise in young healthy individuals.This study aimed to compare flow mediated dilation(FMD)and vascular augmentation index(AIx75)between young adults with low,moderate,and high levels of cardiorespiratory fitness before and after an acute bout of aerobic exercise.Forty-three participants(22 men;21 women)between 18 and 29 years of age completed the study.Participants were classified into low,moderate,and high health-related cardiorespiratory fitness groups according to age-and sex-based relative maximal oxygen consumption(V_O2 max)percentile rankings.FMD was performed using Doppler ultrasound and AIx75 was performed using pulse wave analysis at baseline and 60-min after a 30-min bout of treadmill running at 70%V_O2 max.A significant interaction(p=0.047;ηp 2=0.142)was observed,with the moderate fitness group exhibiting a higher FMD post-exercise compared with baseline([6.7%3.1%]vs.[8.5%2.8%],p=0.028;d=0.598).We found a significant main effect of group for AIx75(p=0.023;ηp 2=0.168),with the high fitness group exhibiting lower AIx75 compared to low fitness group([10%10%]vs.[2%10%],respectively,p=0.019;g=1.07).This was eliminated after covarying for body fat percentage(p=0.489).Our findings suggest that resting FMD and AIx75 responses are not significantly influenced by cardiorespiratory fitness,but FMD recovery responses to exercise may be enhanced in individuals with moderate cardiorespiratory fitness levels.