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Diogo V. Leal, Lee Taylor and John Hough

Purpose: Physical overexertion can lead to detrimental overreaching states without sufficient recovery, which may be identifiable by blunted exercise-induced cortisol and testosterone responses. A running test (RPETP) elicits reproducible plasma cortisol and testosterone elevations (in a healthy state) and may detect blunted hormonal responses in overreached athletes. This current study determined the salivary cortisol and testosterone responses reproducibility to the RPETP, to provide greater practical validity using saliva compared with the previously utilized blood sampling. Second, the relationship between the salivary and plasma responses was assessed. Methods: A total of 23 active, healthy males completed the RPETP on 3 occasions. Saliva (N = 23) and plasma (N = 13) were collected preexercise, postexercise, and 30 minutes postexercise. Results: Salivary cortisol did not elevate in any RPETP trial, and reduced concentrations occurred 30 minutes postexercise (P = .029, η 2 = .287); trial differences were observed (P < .001, η 2 = .463). The RPETP elevated (P < .001, η 2 = .593) salivary testosterone with no effect of trial (P = .789, η 2 = .022). Intraindividual variability was 25% in cortisol and 17% in testosterone. “Fair” intraclass coefficients of .46 (cortisol) and .40 (testosterone) were found. Salivary and plasma cortisol positively correlated (R = .581, P = .037) yet did not for testosterone (R = .345, P = .248). Conclusions: The reproducibility of salivary testosterone response to the RPETP is evident and supports its use as a potential tool, subject to further confirmatory work, to detect hormonal dysfunction during overreaching. Salivary cortisol responds inconsistently in a somewhat individualized manner to the RPETP.

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Ryan Anthony, Michael J. Macartney and Gregory E. Peoples

Delayed onset muscle soreness (DOMS) following eccentric exercise is associated with increased inflammation which can be debilitating. Incorporation of long-chain omega-3 polyunsaturated fatty acids (LC n-3 PUFA), eicosapentaenoic acid, and docosahexaenoic acid into membrane phospholipids provides anti-inflammatory, proresolving, and analgesic effects. This systematic review aims to examine both the quality of studies and the evidence for LC n-3 PUFA in the attenuation of DOMS and inflammation following eccentric exercise, both which of course are empirically linked. The Scopus, Embase, and Web of Science electronic databases were searched to identify studies that supplemented fish oil for a duration of ≥7 days, which included DOMS outcomes following an eccentric exercise protocol. Fifteen (n = 15) studies met inclusion criteria. Eccentric exercise protocols varied from single to multijoint activities. Risk of bias, assessed using either the Cochrane Collaboration tool or the Risk of Bias in Nonrandomized Studies of Interventions tool, was judged as “unclear” or “medium,” respectively, for the majority of outcomes. Furthermore, a custom 5-point quality assessment scale demonstrated that only one (n = 1) study satisfied current recommendations for investigating LC n-3 PUFA. In combination, this highlights widespread inappropriate design protocols among studies investigating the role of LC n-3 PUFA in eccentric exercise. Notwithstanding these issues, LC n-3 PUFA supplementation appears to have favorable effects on eccentric exercise-induced DOMS and inflammatory markers. However, the optimal LC n-3 PUFA supplemental dose, duration, and fatty acid composition will only become clear when study design issues are rectified and underpinned by appropriate hypotheses.

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Andrew N. Bosch, Kirsten C. Flanagan, Maaike M. Eken, Adrian Withers, Jana Burger and Robert P. Lamberts

Elliptical trainers and steppers are proposed as useful exercise modalities in the rehabilitation of injured runners due to the reduced stress on muscles and joints when compared to running. This study compared the physiological responses to submaximal running (treadmill) with exercise on the elliptical trainer and stepper devices at three submaximal but identical workloads. Authors had 18 trained runners (male/female: N = 9/9, age: mean ± SD = 23 ± 3 years) complete randomized maximal oxygen consumption tests on all three modalities. Submaximal tests of 3 min were performed at 60%, 70%, and 80% of peak workload individually established for each modality. Breath-by-breath oxygen consumption, heart rate, fuel utilization, and energy expenditure were determined. The value of maximal oxygen consumption was not different between treadmill, elliptical, and stepper (49.3 ± 5.3, 48.0 ± 6.6, and 46.7 ± 6.2 ml·min−1·kg−1, respectively). Both physiological measures (oxygen consumption and heart rate) as well as carbohydrate and fat oxidation differed significantly between the different exercise intensities (60%, 70%, and 80%) but did not differ between the treadmill, elliptical trainer, and stepper. Therefore, the elliptical trainer and stepper are suitable substitutes for running during periods when a reduced running load is required, such as during rehabilitation from running-induced injury.

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Karl Spiteri, Kate Grafton, John Xerri de Caro and David Broom

The International Physical Activity Questionnaire (IPAQ) is a widely used self-reported physical activity (PA) measure developed to allow for international cross-country comparisons. Due to its unavailability, the aim of this study was to translate the IPAQ-long to Maltese and undertake reliability testing. The IPAQ-long English version was translated into Maltese following the IPAQ guidelines, which included backwards translation. Maltese-speaking participants, aged between 18 and 69 years, were recruited through convenience sampling (n = 170). Participants completed the IPAQ-long twice within an 8- to 48-hr period. PA was calculated in MET minutes per week, and reliability was calculated using the Spearman correlation, intraclass correlation coefficient, concordance correlation coefficient, and Bland–Altman plots. A total of 155 participants completed the questionnaire at two time points. Spearman correlation was .83 (.76–.88) for total PA and .84 (.77–.89) for total sitting time. The intraclass correlation coefficient was .83 (.76–.88) and the concordance correlation coefficient was .75–.87 for total PA. The lowest reliability was for total transport, with a concordance correlation coefficient of .21−.45. Bland–Altman plots highlight that 95% of the differences fell within 2 SDs from the mean. Since the Maltese IPAQ-long has similar reliability to the English version, the authors recommend that health care professionals and PA practitioners use this tool when examining population-level PA among Maltese-speaking individuals.

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Kasper Salin, Anna Kankaanpää, Xiaolin Yang, Tuija H. Tammelin, Costan G. Magnussen, Risto Telama, Nina Hutri-Kähönen, Jorma S.A. Viikari, Olli T. Raitakari and Mirja Hirvensalo

Background: To examine if major life changes over a 4-year period among 34- to 49-year-old adults (mean = 41.8, SD = 5.0) were associated with a change in physical activity in men (37.7%) and women (62.3%). Methods: Daily steps and aerobic steps (steps that lasted for at least 10 min without interruption at a pace of >60 steps/min) were collected from 1051 participants in 2007 and 2011. Changes in marital status, work status, and residence and the birth of a child were determined from both time points. A latent change score model was used to examine mean changes in daily total steps, aerobic steps, and nonaerobic steps (total steps minus aerobic steps). Results: Women who had a first child in the 4-year period had a decrease in their nonaerobic steps (P = .001). Men who divorced in the 4-year period had a decrease in their nonaerobic steps (P = .020), whereas women who recoupled decreased their total steps (P = .030). Conclusions: Counseling for parents having a first child on how to increase physical activity in their everyday life could potentially have an influence on an individual’s physical activity.

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Megan A. Kuikman, Margo Mountjoy, Trent Stellingwerff and Jamie F. Burr

Relative energy deficiency in sport (RED-S) can result in negative health and performance outcomes in both male and female athletes. The underlying etiology of RED-S is low energy availability (LEA), which occurs when there is insufficient dietary energy intake to meet exercise energy expenditure, corrected for fat-free mass, leaving inadequate energy available to ensure homeostasis and adequate energy turnover (optimize normal bodily functions to positively impact health), but also optimizing recovery, training adaptations, and performance. As such, treatment of RED-S involves increasing energy intake and/or decreasing exercise energy expenditure to address the underlying LEA. Clinically, however, the time burden and methodological errors associated with the quantification of energy intake, exercise energy expenditure, and fat-free mass to assess energy availability in free-living conditions make it difficult for the practitioner to implement in everyday practice. Furthermore, interpretation is complicated by the lack of validated energy availability thresholds, which can result in compromised health and performance outcomes in male and female athletes across various stages of maturation, ethnic races, and different types of sports. This narrative review focuses on pragmatic nonpharmacological strategies in the treatment of RED-S, featuring factors such as low carbohydrate availability, within-day prolonged periods of LEA, insufficient intake of bone-building nutrients, lack of mechanical bone stress, and/or psychogenic stress. This includes the implementation of strategies that address exacerbating factors of LEA, as well as novel treatment methods and underlying mechanisms of action, while highlighting areas of further research.

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Courtney M. Butowicz, Julian C. Acasio and Brad D. Hendershot

Altered trunk movements during gait in persons with lower-limb amputation are often associated with an increased risk for secondary health conditions; however, the postural control strategies underlying such alterations remain unclear. In this secondary analysis, the authors employed nonlinear measures of triplanar trunk accelerations via short-term Lyapunov exponents to investigate trunk local stability as well as spatiotemporal gait parameters to describe gait mechanics. The authors also evaluated the influence of a concurrent task on trunk local stability and gait mechanics to explore if competition for neuromuscular processing resources can assist in identifying unique strategies to control kinematic variability. Sixteen males with amputation—8 transtibial and 8 transfemoral—and 8 uninjured males (controls) walked on a treadmill at their self-selected speed (mean = 1.2 m/s ±10%) in 5 experimental conditions (8 min each): 4 while performing a concurrent task (2 walking and 2 seated) and 1 with no concurrent task. Individuals with amputation demonstrated significantly smaller Lyapunov exponents than controls in all 3 planes of motion, regardless of concurrent task or level of amputation (P < .0001). Individuals with transfemoral amputation walked with wider strides compared with individuals with transtibial amputation and controls (P < .0001). Individuals with amputation demonstrated more trunk kinematic variability in the presence of wider strides compared with individuals without amputation, and it appears that performing a concurrent cognitive task while walking did not change trunk or gait mechanics.

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Xiyao Shan, Pavlos Evangelidis, Takaki Yamagishi, Shun Otsuka, Fumiko Tanaka, Shigenobu Shibata and Yasuo Kawakami

This study investigated (a) site- and direction-dependent variations of passive triceps surae aponeurosis stiffness and (b) the relationships between aponeurosis stiffness and muscle strength and walking performance in older individuals. Seventy-nine healthy older adults participated in this study. Shear wave velocities of the triceps surae aponeuroses at different sites and in two orthogonal directions were obtained in a prone position at rest using supersonic shear imaging. The maximal voluntary isometric contraction torque of the plantar flexors and normal (preferred) and fast (fastest possible) walking speeds (5-m distance) were also measured. The shear wave velocities of the adjoining aponeuroses were weakly associated with plantar flexion torque (r = .23–.34), normal (r = .26), and fast walking speed (r = .25). The results show clear spatial variations and anisotropy of the triceps surae aponeuroses stiffness in vivo, and the aponeurosis stiffness was associated with physical ability in older adults.

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Yumeng Li, Jupil Ko, Marika A. Walker, Cathleen N. Brown and Kathy J. Simpson

The purpose of the present study was to examine the effect of chronic ankle instability (CAI) on lower-extremity joint coordination and stiffness during landing. A total of 21 female participants with CAI and 21 pair-matched healthy controls participated in the study. Lower-extremity joint kinematics were collected using a 7-camera motion capture system, and ground reaction forces were collected using 2 force plates during drop landings. Coupling angles were computed based on the vector coding method to assess joint coordination. Coupling angles were compared between the CAI and control groups using circular Watson–Williams tests. Joint stiffness was compared between the groups using independent t tests. Participants with CAI exhibited strategies involving altered joint coordination including a knee flexion dominant pattern during 30% and 70% of their landing phase and a more in-phase motion pattern between the knee and hip joints during 30% and 40% and 90% and 100% of the landing phase. In addition, increased ankle inversion and knee flexion stiffness were observed in the CAI group. These altered joint coordination and stiffness could be considered as a protective strategy utilized to effectively absorb energy, stabilize the body and ankle, and prevent excessive ankle inversion. However, this strategy could result in greater mechanical demands on the knee joint.