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Changes in Physical Activity Associated With a Multicomponent Weight-Loss Randomized Controlled Trial for Youth With Intellectual Disabilities

Richard K. Fleming, Misha Eliasziw, Gretchen A. Dittrich, Carol Curtin, Melissa Maslin, Aviva Must, and Linda G. Bandini

Youth with intellectual disabilities engage in low levels of physical activity (PA). An aim of this family-based weight-loss behavioral intervention (FBBI) trial was to increase and sustain PA in these youth. Accelerometry data were available from 21 individuals with intellectual disabilities, age 14–22 years. Each completed the 6-month FBBI, after which 10 completed a 6-month maintenance intervention (FBBI-M), and 11 received no further intervention (FBBI-C). Twenty participated in a further 6-month follow-up. Accelerometry data were analyzed using linear mixed models. During FBBI, mean (SE) moderate to vigorous PA increased by 4.1 (2.5) min/day and light PA by 24.2 (13.5) min/day. Mean (SE) difference in moderate to vigorous PA between participants in FBBI-M and FBBI-C at 18 months was 14.0 (5.1) min/day (p = .005); mean (SE) difference in light PA was 47.4 (27.4) min/day (p = .08). Increasing PA through behavioral intervention is possible in youth with intellectual disabilities.

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Effect of Personalized Sodium Replacement on Fluid and Sodium Balance and Thermophysiological Strain During and After Ultraendurance Running in the Heat

Alan J. McCubbin and Ricardo J.S. da Costa

Purpose: To investigate the effect of personalized sweat sodium replacement on drinking behavior, sodium and water balance, and thermophysiological responses during and after ultraendurance running in hot conditions. Methods: Nine participants (7 male, 2 female) completed two 5-hour treadmill runs (60% maximum oxygen uptake, 30°C ambient temperature), in a double-blind randomized crossover design, consuming sodium chloride (SODIUM) capsules to replace 100% of previously assessed losses or placebo (PLACEBO). Fluid was consumed ad libitum. Results: No effect of SODIUM was observed for ad libitum fluid intake or net fluid balance (P > .05). Plasma sodium concentration increased in both trials, but to a greater extent in SODIUM at 2.5 hours (mean [SD]: 4 [4] mmol·L−1 vs 1 [5] mmol·L−1; P < .05) and postexercise (4 [3] mmol·L−1 vs 1 [5] mmol·L−1; P < .05). Plasma volume change was not different between trials (P > .05) but was strongly correlated with sodium balance in SODIUM (r = .880, P < .01). No effect of sodium replacement was observed for heart rate, rectal temperature, thermal comfort, perceived exertion, or physiological strain index. During the 24 hours postexercise, ad libitum fluid intake was greater following SODIUM (2541 [711] mL vs 1998 [727] mL; P = .04), as was urinary sodium excretion (NaCl: 66 [35] mmol, Pl: 21 [12] mmol; P < .01). Conclusions: Personalized sweat sodium replacement during ultraendurance running in hot conditions, with ad libitum fluid intake, exacerbated the rise in plasma sodium concentration compared to no sodium replacement but did not substantially influence overall body-water balance or thermophysiological strain. A large sodium deficit incurred during exercise leads to substantial renal sodium conservation postexercise.

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The Future of Para Report Cards on Physical Activity of Children and Adolescents With Disabilities—A Global Call for Engagement, Data, and Advocacy

Mark S. Tremblay, Iryna Demchenko, John J. Reilly, Salomé Aubert, and Cindy Sit

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Performance-Determining Variables of a Simulated Sprint Cross-Country Skiing Competition

Rune Kjøsen Talsnes, Jan-Magnus Brattebø, Tore Berdal, Trine Seeberg, Knut Skovereng, Thomas Losnegard, Jan Kocbach, and Øyvind Sandbakk

Purpose: To investigate performance-determining variables of an on-snow sprint cross-country skiing competition and the evolvement in their relationship with performance as the competition progresses from the individual time trial (TT) to the final. Methods: Sixteen national-level male junior skiers (mean [SD] age, 18.6 [0.8] y; peak oxygen uptake [VO2peak], 67.6 [5.5] mL·min−1·kg−1) performed a simulated sprint competition (1.3 km) in the skating style, comprising a TT followed by 3 finals (quarterfinals, semifinals, and final) completed by all skiers. In addition, submaximal and incremental roller-ski treadmill tests, on-snow maximal speed tests, and strength/power tests were performed. Results: VO2peak and peak treadmill speed during incremental testing and relative heart rate, rating of perceived exertion, blood lactate concentrations, and gross efficiency during submaximal testing were all significantly correlated with performance in the TT and subsequent finals (mean [range] r values: .67 [.53–.86], all P < .05). Relative VO2peak and submaximal relative heart rate and blood lactate concentration were more strongly correlated with performance in the semifinals and final compared with the TT (r values: .74 [.60–.83] vs 0.55 [.51–.60], all P < .05). Maximal speed in uphill and flat terrain was significantly correlated with performance in the TT and subsequent finals (r values: .63 [.38–.70], all P < .05), while strength/power tests did not correlate significantly with sprint performance. Conclusions: VO2peak and high-speed abilities were the most important determinants of sprint cross-country skiing performance, with an increased importance of VO2peak as the competition format progressed toward the final.

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Volume 33 (2023): Issue 6 (Nov 2023)

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Volume 18 (2023): Issue 11 (Nov 2023)

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Evolution of 1500-m Olympic Running Performance

Carl Foster, Brian Hanley, Renato Barroso, Daniel Boullosa, Arturo Casado, Thomas Haugen, Florentina J. Hettinga, Andrew M. Jones, Andrew Renfree, Philip Skiba, Alan St Clair Gibson, Christian Thiel, and Jos J. de Koning

Purpose: This study determined the evolution of performance and pacing for each winner of the men’s Olympic 1500-m running track final from 1924 to 2020. Methods: Data were obtained from publicly available sources. When official splits were unavailable, times from sources such as YouTube were included and interpolated from video records. Final times, lap splits, and position in the peloton were included. The data are presented relative to 0 to 400 m, 400 to 800 m, 800 to 1200 m, and 1200 to 1500 m. Critical speed and D′ were calculated using athletes’ season’s best times. Results: Performance improved ∼25 seconds from 1924 to 2020, with most improvement (∼19 s) occurring in the first 10 finals. However, only 2 performances were world records, and only one runner won the event twice. Pacing evolved from a fast start–slow middle–fast finish pattern (reverse J-shaped) to a slower start with steady acceleration in the second half (J-shaped). The coefficient of variation for lap speeds ranged from 1.4% to 15.3%, consistent with a highly tactical pacing pattern. With few exceptions, the eventual winners were near the front throughout, although rarely in the leading position. There is evidence of a general increase in both critical speed and D′ that parallels performance. Conclusions: An evolution in the pacing pattern occurred across several “eras” in the history of Olympic 1500-m racing, consistent with better trained athletes and improved technology. There has been a consistent tactical approach of following opponents until the latter stages, and athletes should develop tactical flexibility, related to their critical speed and D′, in planning prerace strategy.

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Partly Substituting Whey for Collagen Peptide Supplementation Improves Neither Indices of Muscle Damage Nor Recovery of Functional Capacity During Eccentric Exercise Training in Fit Males

Ruben Robberechts, Chiel Poffé, Noémie Ampe, Stijn Bogaerts, and Peter Hespel

Previous studies showed that collagen peptide supplementation along with resistance exercise enhance muscular recovery and function. Yet, the efficacy of collagen peptide supplementation in addition to standard nutritional practices in athletes remains unclear. Therefore, the objective of the study was to compare the effects of combined collagen peptide (20 g) and whey protein (25 g) supplementation with a similar daily protein dose (45 g) of whey protein alone on indices of muscle damage and recovery of muscular performance during eccentric exercise training. Young fit males participated in a 3-week training period involving unilateral eccentric exercises for the knee extensors. According to a double-blind, randomized, parallel-group design, before and after training, they received either whey protein (n = 11) or whey protein + collagen peptides (n = 11). Forty-eight hours after the first training session, maximal voluntary isometric and dynamic contraction of the knee extensors were transiently impaired by ∼10% (P time < .001) in whey protein and whey protein + collagen peptides, while creatine kinase levels were doubled in both groups (P time < .01). Furthermore, the training intervention improved countermovement jump performance and maximal voluntary dynamic contraction by respectively 8% and 10% (P time < .01) and increased serum procollagen type 1N-terminal peptide concentration by 10% (P time < .01). However, no differences were found for any of the outcomes between whey and whey protein + collagen peptides. In conclusion, substituting a portion of whey protein for collagen peptide, within a similar total protein dose, improved neither indices of eccentric muscle damage nor functional outcomes during eccentric training.

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Reliability of Accuracy and Precision Tests for Elite Para Table Tennis Players

Szymon Galas, Marcin Andrzejewski, and Beata Pluta

The primary purpose of this study was to adapt selected accuracy and precision tests in table tennis to the specific skills of elite table tennis players with impairment. The study included a sample of 23 Para table tennis players with an average age of 31.8 ± 12.22 years (including 30.4% females) who belonged to the senior Polish Para table tennis team. A battery of six tests evaluating stroke accuracy and serve precision was assessed. The analysis of the reliability of these tests confirmed the legitimacy of using this battery of accuracy and precision tests to assess the skills of Para table tennis players in all three integrated sport classes: players in wheelchairs, in a standing position, and with intellectual impairment. Analysis of the data obtained from the tests could provide coaches with relevant information regarding elite Para table tennis players’ level of performance and examine selected accuracy and precision elements of their individual technique.

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A Comparison of Critical Speed and Critical Power in Runners Using Stryd Running Power

Cody R. van Rassel, Kate M. Sales, Oluwatimilehin O. Ajayi, Koki Nagai, and Martin J. MacInnis

Purpose: Although running traditionally relies on critical speed (CS) as an indicator of critical intensity, portable inertial measurement units offer a potential solution for estimating running mechanical power to assess critical power (CP) in runners. The purpose of this study was to determine whether CS and CP differ when assessed using the Stryd device, a portable inertial measurement unit, and if 2 running bouts are sufficient to determine CS and CP. Methods: On an outdoor running track, 10 trained runners ( V ˙ O 2 max , 59.0 [4.2] mL·kg−1·min−1) performed 3 running time trials (TT) between 1200 and 4400 m on separate days. CS and CP were derived from 2-parameter hyperbolic speed–time and power–time models, respectively, using 2 (CS2TT and CP2TT) and 3 (CS3TT and CP3TT) TTs. Subsequently, runners performed constant-intensity running for 800 m at their calculated CS3TT and CP3TT. Results: Running at the calculated CS3TT speed (3.88 [0.44] m·s−1) elicited an average Stryd running power (271 [28] W) not different from the calculated CP3TT (270 [28]; P = .940; d = 0.02), with excellent agreement between the 2 values (intraclass correlation coefficient = .980). The CS2TT (3.97 [0.42] m·s−1) was not higher than CS3TT (3.89 [0.44] m·s−1; P = .178; d = 0.46); however, CP2TT (278 [29] W) was greater than CP3TT (P = .041; d = 0.75). Conclusion: The running intensities at CS and CP were similar, supporting the use of running power (Stryd) as a metric of aerobic fitness and exercise prescription, and 2 trials provided a reasonable, albeit higher, estimate of CS and CP.