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Liam D. Corr, Adam Field, Deborah Pufal, Jenny Killey, Tom Clifford, Liam D. Harper and Robert J. Naughton

Polyphenol consumption has become a popular method of trying to temper muscle damage. Cocoa flavanols (CF) have attracted attention due to their high polyphenol content and palatability. As such, this study will investigate whether an acute dose of CF can aid recovery following exercise-induced muscle damage. The study was a laboratory-based, randomized, single-blind, nutrient-controlled trial involving 23 participants (13 females and 10 males). Participants were randomized into either control ∼0 mg CF (n = 8, four females); high dose of 830 mg CF (CF830, n = 8, five females); or supra dose of 1,245 mg CF (CF1245, n = 7, four females). The exercise-induced muscle damage protocol consisted of five sets of 10 maximal concentric/eccentric hamstring curls and immediately consumed their assigned drink following completion. To measure muscle recovery, maximal voluntary isometric contraction (MVIC) of the knee flexors at 60° and 30°, a visual analog scale (VAS), and lower-extremity function scale were taken at baseline, immediately, 24-, 48-, and 72-hr postexercise-induced muscle damage. There was a main effect for time for all variables (p < .05). However, no significant differences were observed between groups for all measures (p ≥ .17). At 48 hr, there were large effect sizes between control and CF1245 for MVIC60 (p = .17, d = 0.8); MVIC30 (p = .26, d = 0.8); MVIC30 percentage change (p = .24 d = 0.9); and visual analog scale (p = .25, d = 0.9). As no significant differences were observed following the consumption of CF, there is reason to believe that CF offer no benefit for muscle recovery when ingested acutely.

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Cédric Leduc, Jason Tee, Mathieu Lacome, Jonathon Weakley, Jeremy Cheradame, Carlos Ramirez and Ben Jones

Purpose: To investigate the convergent validity, reliability, and sensitivity over a week of training of a standardized running test to measure neuromuscular fatigue. Methods: Twenty male rugby union players were recruited for the study, which took place during preseason. The standardized running test consisted of four 60-m runs paced at  ~5 m·s−1 with 33 seconds of recovery between trials. Data from micromechanical electrical systems were used to calculate a running-load index (RLI), which was a ratio between the mechanical load and the speed performed during runs. RLI was calculated by using either the entire duration of the run or a constant-velocity period. For each type of calculation, either an individual directional or the sum of the 3 components of the accelerometer was used. A measure of leg stiffness was used to assess the convergent validity of the RLI. Results: Unclear to large relationships between leg stiffness and RLI were found (r ranged from −.20 to .62). Regarding reliability, small to moderate (.47–.86) standardized typical errors were found. The sensitivity analysis showed that the leg stiffness presented a very likely trivial change over the course of 1 week of training, whereas RLI showed very likely small to a most likely large change. Conclusions: This study showed that RLI is a practical method to measure neuromuscular fatigue. In addition, such a methodology aligns with the constraint of elite team-sport setup due to its ease of implementation in practice.

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Thomas D. Raedeke, Victoria Blom and Göran Kenttä

This study evaluated the relationship of perfectionism and self-perceptions with burnout and life satisfaction in aesthetic performers (N = 254) recruited in Sweden. Cluster analysis revealed four groups: perfectionistic with maladaptive self-perceptions, perfectionistic (parent-driven) with maladaptive self-perceptions, achievement-oriented with adaptive self-perceptions, and nonperfectionistic with adaptive self-perceptions. Performers in both maladaptive clusters reported characteristics suggesting they were perfectionistic compared to their peers. They also reported relatively high contingent self-worth and low basic self-esteem. In contrast, those in the nonperfectionistic with adaptive self-perceptions cluster scored relatively low on perfectionism and reported relatively high basic self-esteem and low contingent self-worth. The performers in the achievement-oriented with adaptive self-perceptions cluster reported average scores across most variables, moderately high personal standards, and higher basic self-esteem compared with contingent self-worth. Overall, performers in both maladaptive clusters reported the highest burnout and lowest life satisfaction. Study findings underscore the importance of perfectionism and self-perceptions when considering burnout and life satisfaction.

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Thomas W. Jones, Barry C. Shillabeer and Marco Cardinale

Context: The application of infrared thermography to assess the effects of athletic training is increasing. It is not known if changes in skin temperature (Tsk) as assessed by infrared thermography are affected by the training load or the muscle soreness experienced by the athlete. Purpose : To describe the variations in Tsk in body areas affected by running training and examine any relationships with subjective ratings of muscle soreness. The secondary aim was to assess the feasibility of using infrared thermography for assessing training load in 2 junior male middle-distance athletes. Methods: Data were collected over a 42-d observational period with Tsk of the quadriceps, knees, shins, lateral hamstrings, biceps femoris, and Achilles tendons, and the subjective ratings of muscle soreness were taken each morning prior to any training. All training load was quantified through heart rate, running speed, and distance covered. Changes in Tsk outside the typical error were identified. Relationships between Tsk and subjective ratings of muscle soreness were also examined. Results: Over the 42-d observational period, mean Tsk of the regions of interest was reported outside the typical error on day 31 and day 22 for athletes 1 and 2, respectively. These changes in Tsk did not follow trends similar to those of to training loadings. No significant relationships were observed between Tsk of any regions of interest and muscle soreness. Conclusions: Although Tsk changed outside the typical error throughout the 42-d observational period, these changes were not reflective of training load quantified through cardiovascular strain or subjective ratings of muscle soreness.

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Christopher Kirk, Carl Langan-Evans and James P. Morton

Body mass (BM) manipulation via rapid weight loss (RWL) and rapid weight gain (RWG) is a common practice among mixed martial art (MMA) athletes to ensure qualification for the division in which the athlete wishes to compete. Professional MMA competitors in California are required to weigh in twice: 24 hr prior to competition and immediately prior to the bout after they have typically engaged in RWG. In analyzing data from five MMA events sanctioned by the Californian State Athletic Commission, the authors used Bayesian analyses to compare bout winners (n = 31) and losers (n = 31) in terms of in-competition BM (in kilograms) and the amount of BM regained between the two weigh-ins (in kilograms). These data do not support the hypothesis that differences in in-competition BM (Bayes factor [BF10] = 0.667, d = 0.23) or the amount of BM regained between the two weigh-ins (BF10 = 0.821, d = 0.23) determine winning or losing. In addition, there was no statistical difference between bouts ending via strikes, submission, or decision for either in-competition BM (BF10 = 0.686, ω2 < 0.01) or the amount of BM regained between the two weigh-ins (BF10 = 0.732, ω2 = 0.054). In conclusion, the authors report for the first time that the magnitude of RWG does not predict winning or losing in a professional cohort of MMA athletes. In addition, they also report that MMA athletes typically compete at a BM that is at least 1–2 divisions higher than the division in which they officially weighed-in. These analyses may provide impetus for governing bodies and coaches to enact changes at both professional and amateur levels to reduce negative health consequences associated with extreme RWL and RWG.

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Maureen R. Weiss, Lindsay E. Kipp, Alison Phillips Reichter and Nicole D. Bolter

Purpose: Girls on the Run (GOTR), a physical activity-based positive youth development program, uses running as a platform to teach life skills and promote healthy behaviors. In this companion paper of our comprehensive project, the authors evaluated program impact on positive youth development by comparing GOTR participants to youth in other organized activities (Sport and physical education [PE]) on life skills transfer and social processes. Qualitative methods complemented quantitative data through interviews with GOTR stakeholders. Method: The participants included 215 girls in GOTR and 692 girls in the same grades and schools who did not participate in GOTR (Sport = 485; PE = 207). They completed self-report measures of life skills transfer, peer and coach relatedness, and coach autonomy support at the season’s end. GOTR subsamples of girls, coaches, caregivers, and school personnel participated in focus groups. Results: Girls in GOTR compared favorably to the Sport and PE girls on all life skills—managing emotions, resolving conflicts, helping others, and making intentional decisions—and to the PE girls for all 3 social processes. The GOTR and Sport girls did not differ on coach relatedness and autonomy support, but the Sport girls rated teammate relatedness higher. The GOTR girls’ scores on life skills transfer remained stable at a 3-month follow-up assessment. Stakeholders in the focus groups shared corroborating evidence that, through participating in GOTR, girls learn skills that generalize to school and home contexts. Conclusion: Using comparison groups, a retention assessment, and mixed methods, the findings provide evidence that GOTR is effective in teaching skills and strategies that generalize to broader life domains. The processes that explain group differences on life skills transfer include GOTR’s intentional curriculum of skill-building activities delivered by coaches within a caring and autonomy-supportive climate.

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Ashley A. Herda, Brianna D. McKay, Trent J. Herda, Pablo B. Costa, Jeffrey R. Stout and Joel T. Cramer

The purpose of this trial was to examine the effects of self-selected exercise intensities plus either whey protein or placebo supplementation on vital signs, body composition, bone mineral density, muscle strength, and mobility in older adults. A total of 101 participants aged 55 years and older (males [n = 34] and females [n = 67]) were evaluated before and after 12 weeks of self-selected, free-weight resistance exercise plus 30 min of self-paced walking three times per week. The participants were randomized into two groups: whey protein (n = 46) or placebo (n = 55). Three-way mixed factorial analyses of variance were used to test for mean differences for each variable. The 12 weeks of self-selected, self-paced exercise intensities improved resting heart rate, fat-free mass, percent body fat, handgrip strength, bench press strength, leg press strength, and all mobility measurements (p < .05) in males and females despite supplementation status. This suggests that additional protein in well-fed healthy older adults does not enhance the benefit of exercise.

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Chantelle Zimmer, Janice Causgrove Dunn and Nicholas L. Holt

Children with developmental coordination disorder (DCD) may experience stress in physical activity contexts due to emphasis on their poor motor skills. The purpose of this study was to explore the lived experiences of children at risk for DCD in physical education in order to develop a deeper understanding about what they experience as stress and how they cope with it. Using interpretative phenomenological analysis, six children in Grades 4–6 participated in two semistructured interviews. A motivational (and developmental) stress and coping theory informed interpretation of the three themes that described the children’s experiences: (a) they hurt me—psychological and physical harm sustained from peers, (b) it’s hard for me—difficulties encountered in activities, and (c) I have to—pressure to meet the teacher’s demands. Although the children at risk for DCD were confronted with various stressors in physical education, they coped more adaptively when social support was provided.

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David Barranco-Gil, Jaime Gil-Cabrera, Pedro L. Valenzuela, Lidia B. Alejo, Almudena Montalvo-Pérez, Eduardo Talavera, Susana Moral-González and Alejandro Lucia

Purpose: The functional threshold power (FTP), which demarcates the transition from steady state to non-steady-state oxidative metabolism, is usually determined with a 20-minute cycling time trial that follows a standard ∼45-minute warm-up. This study aimed to determine if the standard warm-up inherent to FTP determination is actually necessary and how its modification or removal affects the relationship between FTP and the respiratory compensation point (RCP). Methods: A total of 15 male cyclists (age 35 [9] y, maximum oxygen uptake 66.4 [6.8] mL·kg−1·min−1) participated in this randomized, crossover study. Participants performed a ramp test for determination of RCP and maximum oxygen uptake. During subsequent visits, they performed a 20-minute time trial preceded by the “standard” warm-up that is typically performed before an FTP test (S-WU), a 10-minute warm-up at the power output (PO) corresponding to 60% of maximum oxygen uptake (60%-WU), or no warm-up (No-WU). FTP was computed as 95% of the mean PO attained during the time trial. Results: Although the FTP was correlated with the RCP independently of the warm-up (r = .89, .93, and .86 for No-WU, 60%-WU, and S-WU, respectively; all Ps < .001), the PO at RCP was higher than the FTP in all cases (bias ± 95% limits of agreement = 57 [24], 60 [23], and 57 [32] W for No-WU, 60%-WU, and S-WU, respectively; all Ps < .001 and effect size > 1.70). Conclusions: The FTP is highly correlated with the RCP but corresponds to a significantly lower PO, being these results independent of the warm-up performed (or even with no warm-up).

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Jan-Michael Johansen, Sondre Eriksen, Arnstein Sunde, Øystein B. Slettemeås, Jan Helgerud and Øyvind Støren

Purpose: To investigate the effect of a double-poling (DP) high-intensity aerobic interval-training (HIT) intervention performed without increasing total HIT volume. This means that regular HIT training (eg, running) was replaced by HIT DP. The aim was to explore whether this intervention could improve peak oxygen uptake in DP, the fractional utilization of maximal oxygen uptake (VO2max) in DP, oxygen cost of DP, maximal aerobic speed, and a 3-km DP time trial. Methods: Nine non-specially-DP-trained cross-country skiers (intervention group) and 9 national-level cross-country skiers (control group) were recruited. All participants were tested for VO2max in running, peak oxygen uptake in DP, oxygen cost of DP, and time-trial performance before and after a 6-wk, 3-times-per-week HIT DP intervention. The intervention group omitted all regular HIT with HIT in DP, leaving the total weekly amount of HIT unchanged. Results: Seven participants in each group completed the study. VO2max in running remained unchanged in both groups, whereas peak oxygen uptake in DP improved by 7.1% (P = .005) in the intervention group. The fractional utilization of VO2max in DP thus increased by 7.3% (P = .019), oxygen cost of DP by 9.2% (P = .047), maximal aerobic speed by 16.5% (P = .009), and time trial by 19.5% (P = .004) in the intervention group but remained unchanged in the control group. Conclusions: The results indicate that a 6-wk HIT DP intervention could be an effective model to improve DP-specific capacities, with maintenance of VO2max in running.