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Lauren C. Benson and Kristian M. O’Connor

About half of all runners sustain a running-related injury every year. Exertion may contribute to risk of injury by altering joint mechanics. The purpose of this study was to examine the effects of exertion on runners’ joint mechanics using principal component analysis (PCA). Three-dimensional motion analysis of the lower extremity was performed on 16 healthy female runners before and after their typical training run. PCA was used to determine exertion-related changes in joint mechanics at the ankle, knee, and hip. Statistical significance for repeated-measures MANOVA of the retained principal components at each joint and plane of motion was at P < .05. Exercise effects were identified at the ankle (greater rate of eversion [PC2: P = .027], and decreased plantar flexion moment [overall: P = .044] and external rotation moment [PC3: P = .003]), knee (increased adduction [overall: P = .044] and internal rotation [PC3: P = .034], and decreased abduction moment [overall: P = .045]), and hip (increased internal rotation [PC1: P = .013] and range of mid- to late-stance rotation [PC2: P = .009], and decreased internal rotation moment [PC1: P = .001]). The observed changes in running mechanics reflect a gait profile that is often linked to running injury. The effects of more strenuous activity may result in mechanics that present an even greater risk for injury.

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Abby R. Fleming, Nic Martinez, Larry H. Collins, Candi D. Ashley, Maureen Chiodini, Brian J. Waddell, and Marcus W. Kilpatrick

.5) with 80% power using a t test between means with alpha at .05 and a two-tailed test. The effect size (ES) used in the calculation is based on previous research from our laboratory evaluating exertion, affect, and enjoyment ( Kilpatrick, Greeley, & Collins, 2015 ; Martinez et al., 2015 ) and more

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Luis Peñailillo, Karen Mackay, and Chris R. Abbiss

Rating of perceived exertion (RPE) is one of the most utilized measurements in exercise and sports science settings. Exercise-induced increases in psychophysiological stress are extremely important in many aspects of exercise capacity and performance including the development and perceptions of

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Kenneth E. Games, Zachary K. Winkelmann, and Lindsey E. Eberman

Key Points ▸ Static and dynamic balance are negatively impacted following a physical exertion activity. ▸ The balance deficits identified in response to exertion may provide insights into the injury risk profiles of firefighters wearing a personal protective ensemble. ▸ Job-related tasks involving

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Barbara E. Ainsworth, Robert G. McMurray, and Susan K. Veazey

The purpose of this study was to determine the accuracy of two submaximal exercise tests, the Sitting-Chair Step Test (Smith & Gilligan. 1983) and the Modified Step Test (Amundsen, DeVahl, & Ellingham, 1989) to predict peak oxygen uptake (VO2 peak) in 28 adults ages 60 to 85 years. VO2 peak was measured by indirect calorimetry during a treadmill maximal graded exercise test (VO2 peak, range 11.6–31.1 ml · kg −l · min−1). In each of the submaximal tests, VO2 was predicted by plotting stage-by-stage submaximal heart rate (HR) and perceived exertion (RPE) data against VO2 for each stage and extrapolating the data to respective age-predicted maximal HR or RPE values. In the Sitting-Chair Step Test (n = 23), no significant differences were observed between measured and predicted VO2 peak values (p > .05). However, predicted VO2 peak values from the HR were 4.3 ml · kg−1 · min−1 higher than VO2 peak values predicted from the RPE data (p < .05). In the Modified Step Test (n = 22), no significant differences were observed between measured and predicted VO2 peak values (p > .05). Predictive accuracy was modest, explaining 49–78% of the variance in VO2 peak. These data suggest that the Sitting-Chair Step Test and the Modified Step Test have moderate validity in predicting VO2 peak in older men and women.

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Jenna Morogiello and Rebekah Roessler

Key Points ▸ First case report of exertional rhabdomyolysis (ER) in a noncontact intramural sport. ▸ Early recognition and treatment is crucial to prevent potentially fatal complications. ▸ Recreational sports pose a unique challenge for health care professionals. ▸ Highlights the need for athletic

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Mohamed Saifeddin Fessi and Wassim Moalla

rating of perceived exertion (RPE) is a common simple, valid, reliable, and low-cost method that represents the athlete’s own perception of training stress and gives a complete indication of the global workload because it is indicative of both physiological and psychological load. 8 , 14 Accordingly

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Margaret C. Morrissey, Michael R. Szymanski, Andrew J. Grundstein, and Douglas J. Casa

Exertional heat stroke (EHS) is a life-threatening condition characterized by an internal temperature ≥40°C with central-nervous-system dysfunction ( Casa et al., 2015 ). EHS is interesting to study when examining prevention strategies and factors that predispose individuals to develop the

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Kirk J. Cureton, Gordon L. Warren, Mindy L. Millard-Stafford, Jonathan E. Wingo, Jennifer Trilk, and Maxime Buyckx

This double-blind experiment examined the effects of a caffeinated sports drink during prolonged cycling in a warm environment. Sixteen highly trained cyclists completed 3 trials: placebo, carbohydrate-electrolyte sports drink (CES), and caffeinated sports drink (CES+CAF). Subjects cycled for 135 min, alternating between 60% and 75% VO2max every 15 min for the first 120 min, followed by a 15-min performance ride. Maximal voluntary (MVC) and electrically evoked contractile properties of the knee extensors were measured before and after cycling. Work completed during the performance ride was 15–23% greater for CES+CAF than for the other beverages. Ratings of perceived exertion were lower with CES+CAF than with placebo and CES. After cycling, the MVC strength loss was two-thirds less for CES+CAF than for the other beverages (5% vs. 15%). Data from the interpolated-twitch technique indicated that attenuated strength loss with CES+CAF was explained by reduced intrinsic muscle fatigue.

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Rebecca L. Dubas, Elizabeth F. Teel, Melissa C. Kay, Eric D. Ryan, Meredith A. Petschauer, and Johna K. Register-Mihalik

injury. 5 – 7 While the Sport Concussion Assessment Tool 5th Edition (SCAT-5) is now the current version, most key measures and the lack of administration guidelines are consistent across both tools. Exertion, or physical activity that causes cardiovascular stress or a sympathetic nervous response, can