Acute moderate exercise does not attenuate cardiometabolic function associated with a bout of prolonged sitting.

Epidemiological studies suggest that prolonged sitting increases all-cause mortality; yet, physiological causes underpinning prolonged sitting remain elusive. We evaluated cardiometabolic function during prolonged sitting (5 h) in 10 adults with and without 30 min of moderate exercise leading up to the sitting. Mean arterial blood pressure (MAP), heart rate (HR) and posterior tibial artery blood velocity were measured at baseline and every hour subsequently. Blood glucose was measured at baseline, 3 and 5 h, with consumption of a caloric beverage at 1 h. Seated MAP and HR values were ~17 mmHg (P < 0.001) and ~4 bpm (P < 0.05) higher for the moderate exercise versus sitting conditions. A ~ 4 cm·s(-1) (16%) (P < 0.05) decline in posterior tibial artery blood velocity from prolonged sitting was observed, with no benefit conferred from moderate exercise. Postprandial glucose metabolism was not different between conditions (P > 0.05). We conclude prolonged sitting may be related to decreased posterior tibial artery blood velocity. Moreover, an acute bout of moderate exercise does not seem to attenuate cardiometabolic function during prolonged sitting in healthy, young adults.

Do the noncaffeine ingredients of energy drinks affect metabolic responses to heavy exercise?

Energy drinks (EDs) such as Red Bull (RB) are marketed to enhance metabolism. Secondary ingredients of EDs (e.g., taurine) have been purported to improve time trial performance; however, little research exists on how such secondary ingredients affect aerobic metabolism during heavy exercise. The purpose of this study was to investigate the effect of the secondary ingredients of RB on aerobic metabolism during and subsequent to heavy exercise. In double-blind, counterbalanced, and crossover fashion, 8 recreationally trained individuals completed a graded exercise test to determine the gas exchange threshold (GET). Subjects returned on 2 separate occasions and ingested either a 245 ml serving of RB or a control (CTRL) drink with the equivalent caffeine before engaging in two 10-minute constant-load cycling bouts, at an intensity equivalent to GET, with 3 minutes of rest between bouts. Accumulated liters of O2 (10 minutes) were higher for the first bout (17.1 ± 3.5 L) vs. the second bout (16.7 ± 3.5 L) but did not differ between drinks. Similarly, excess postexercise oxygen consumption was higher after the initial bout (RB mean, 2.6 ± 0.85 L; CTRL mean, 2.9 ± 0.90 L) vs. the second bout (RB mean, 1.5 ± 0.85 L; CTRL mean, 1.9 ± 0.87 L) but did not differ between drinks. No differences occurred between drinks for measures of heart rate or rating of perceived exertion. These results indicate that the secondary ingredients contained in a single serving of RB do not augment aerobic metabolism during or subsequent to heavy exercise.

Reliability analysis of the 3-min all-out exercise test for cycle ergometry.

UNLABELLED: The 3-min all-out exercise test (3 MT) is purported to estimate critical power (CP) and anaerobic work capacity (W') and serve as an exercise mode for measuring maximum oxygen uptake (VO(2max)). Reliability analysis of the 3 MT has been confined to CP, not W', and verification of "true" VO(2max)was exclusive to a graded exercise test (GXT). PURPOSE: We conducted a reliability analysis of the 3 MT and compared VO(2max)values from the 3 MT with a GXT and an exhaustive square-wave verification bout. METHODS: Upon completion of a custom GXT and square-wave verification protocol, 11 subjects of various aerobic powers completed two 3 MTs (separate visits). CP, W', average power during 150 s from the 3 MT, and VO(2max)values were assessed using typical error (TE), coefficient of variation (CV), and intraclass correlation (α). RESULTS: CP (W) (trial 1 = 206 ± 47, trial 2 = 206 ± 42) did not differ between 3 MT trials (P = 0.37) and was reliable (TE = 15 W, CV = 7%, α = 0.93). W' was less reliable (TE = 2864 J, CV = 28%, α = 0.76) but did not alter power-duration estimates from the two 3 MTs (P > 0.05). Variability for VO(2max)(TE (mL·kg(-1)·min(-1)) between the GXT and the verification bout (1.16) was more consistent than the first (2.03) or second (2.69) 3 MT. CONCLUSIONS: The 3 MT yields reliable estimates of CP and consistent estimates of the power-duration relationship. Power for 150 s, in comparison with W', is a more reliable metric of short-term power performance. The square-wave protocol is recommended over the 3 MT for verifying true VO(2max).

Enforcement of Mouthguard Use and Athlete Compliance in National Collegiate Athletic Association Men's Collegiate Ice Hockey Competition.

OBJECTIVE: To determine enforcement patterns and athlete compliance with the National Collegiate Athletic Association (NCAA) rule requiring the wearing of mouthguards in men's collegiate ice hockey games during a single competitive season. DESIGN AND SETTING: We developed a questionnaire and sent it to certified athletic trainers (ATCs) directly responsible for men's varsity collegiate ice hockey at 127 NCAA-affiliated institutions. Then chi(2) analyses were conducted to determine whether significant differences existed in the pattern of responses by division of play (Division I, II, or III or independent). SUBJECTS: A total of 104 ATCs responded. We obtained data from 94 questionnaires with complete answers to primary questions addressing program enforcement of the rule and mouthguard use. MEASUREMENTS: Our questionnaire asked about types of mouthguards used, attitudes of the sports medicine and coaching staffs regarding the role of mouthguards in prevention of injury, enforcement of mouthguard use, and actual numbers of athletes wearing mouthguards in competition. Respondents also provided an estimate of the number of penalties assessed against their team for mouthguard violations during the previous season. RESULTS: Most ATCs (93%) reported that they believed mouthguards play a role in injury prevention. Respondents indicated someone on the coaching or sports medicine staff enforced the rule at 74% of the institutions, with a trend toward greater enforcement at the Division II and III levels. Overall, ATCs reported 63% of athletes consistently wore mouthguards in competition, with significantly higher compliance at the Division II and III levels. A total of 19 penalties were reportedly assessed for violation of the mouthguard rule the previous season. CONCLUSIONS: Our data suggest that the use of mouthguards in competition is not consistently enforced by ATCs, coaches, or game officials and that mouthguards are not routinely worn by athletes. These results raise legitimate concerns for all physicians, athletic trainers, coaches, and governing bodies involved with men's collegiate ice hockey.