Aerobic exercise training in older men and women-Cerebrovascular responses to submaximal exercise: Results from the Brain in Motion study.

Physical inactivity is a leading modifiable risk factor for cardiovascular and cerebrovascular disease, cognitive dysfunction, and global mortality. Regular exercise might mitigate age-related declines in cardiovascular and cerebrovascular function. In this study, we hypothesize that a 6-month aerobic exercise intervention will lead to a decrease in cerebrovascular resistance index (CVRi) and to an increase in cerebral blood flow (CBF) and cerebrovascular conductance index (CVCi) during two submaximal exercise workloads (40% VO2 max and 65 W), intensities that have been shown to be comparable to activities of daily life. Two hundred three low-active healthy men and women enrolled in the Brain in Motion study, completed a 6-month exercise intervention and underwent submaximal and maximal tests pre-/post-intervention. The intervention improved the gas exchange threshold and maximal oxygen consumption (VO2 max), with no change in heart rate at VO2 max, during the treadmill VO2 max test. Heart rate and CVRi decreased from pre-intervention values during both relative (40% VO2 max) and absolute (65 W) submaximal exercise tests. Blood flow velocity in the middle cerebral artery and CVCi increased post-intervention during 40% VO2 max and 65 W. Changes in mean arterial pressure were found only during the absolute component (65 W). Our study demonstrates that aerobic exercise improves not only cardiorespiratory indices but also cerebrovascular function at submaximal workloads which may help to mitigate age-related declines in everyday life. Investigation of the mechanisms underlying the decline in cardiovascular and cerebrovascular capacity with aging has important implications for the maintenance of health and continued independence of older adults.

Injuries in Youth Volleyball Players at a National Championship: Incidence, Risk Factors, and Mechanisms of Injury.

OBJECTIVE: To evaluate injury incidence rates, types, mechanisms, and potential risk factors in youth volleyball. DESIGN: Prospective cohort. SETTING: 2018 Canadian Youth National Volleyball Tournament. PARTICIPANTS: Thousand eight hundred seventy-six players [466 males, 1391 females, mean age 16.2 years (±1.26)] consented to participate (19.5%). ASSESSMENT OF RISK FACTORS: Sex (male/female), age group, position, and underage players. MAIN OUTCOME MEASURES: Players completed a questionnaire (demographic information, injury, and concussion history). Medical attention injuries were recorded by tournament medical personnel through an injury report form (eg, mechanism and type). Injury was defined as any physical complaint seeking onsite medical attention. Concussion was defined using the fifth International Consensus. Injury rates adjusted for cluster by team were calculated by sex. Exploratory multivariable Poisson regression was used to analyze potential risk factors (eg, sex, age group, position, and underage players) for injury, adjusted for cluster by team and offset by athlete exposures (AEs). RESULTS: There were 101 injuries in the 7-day tournament {IRFemale = 6.78 injuries/1000 AEs [95% confidence interval (CI), 5.27-8.72]; IRMale = 4.30 injuries/1000 AEs (95% CI, 2.55-7.24)}. Joint sprain (n = 29, 28.71%) and concussion (n = 26, 25.74%) were the most common. Most concussions were associated with ball-to-head contact (61.5%). There was no statistically significant difference in injury rate by sex (IRRF/M: 1.47; 95% CI, 0.80-2.69). The rates of injury in U14 were higher than U18 (IRRU14: 2.57; 95% CI, 1.11-5.98). CONCLUSIONS: Injury rates are high in youth volleyball tournament play, with the highest rates in U14. More research is needed to inform the development of volleyball-specific injury prevention strategies.