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Leonardo F. Ferreira, Kenneth S. Campbell, and Michael B. Reid

N-acetylcysteine (NAC) is a thiol donor with antioxidant properties that has potential use as an ergogenic aid. However, NAC is associated with adverse reactions that limit its use in humans.


The authors evaluated NAC efficacy as a thiol donor before handgrip exercise, measuring changes in serum cysteine and glutathione status and recording adverse reactions in adult subjects across a range of doses.


Healthy individuals ingested NAC capsules (9 ± 2 or 18 ± 4 mg/kg) or solution (0, 35, 70, or 140 mg/kg). Venous blood samples were collected and subjects answered a questionnaire about adverse reactions.


Low doses of NAC (capsules) did not affect plasma cysteine or glutathione or cause adverse reactions. Adverse reactions to NAC solution were predominantly mild and gastrointestinal (GI). Intensity of GI reactions to 140 mg/kg NAC was significantly higher than placebo (in a.u., 0.67 ± 0.16 vs. 0.07 ± 0.04; p < .05). Plasma cysteine concentration increased with NAC dose from 9.3 ± 0.7 μM (placebo) to 65.3 ± 6.7 μM (140 mg/kg); however, there was no difference (p > .05) in plasma cysteine for 70 mg/kg vs. 140 mg/kg. Similar increases were observed for the ratio of cysteine to total cysteine, which was directly related to handgrip exercise performance. Plasma glutathione was elevated and oxidized glutathione diminished (p < .05) with NAC 140 mg/kg vs. placebo.


NAC effects on plasma thiols are maximized by oral administration of 70 mg/kg, a dose that does not cause significant adverse reactions.

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Donal E. Muir

Tennis is examined as a recreational activity conducted within the context of a social system, in this case a tennis club. Participant observation revealed that this “leisure sport” was in fact highly work-like—the pursuit of athletic status being structured by a system of “implicit-tournament” norms defining where, when, and with whom one played—a predictable side effect of the dominant U.S. culture, with its economic ideology of laissez-faire capitalism and blurred distinction between work and play.

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Jaime Fernandez-Fernandez, Alejandro Lopez-Valenciano, Jose Vicente Garcia-Tormo, David Cabello-Manrique, and Juan García-López

Purpose: To analyze the influence of playing 2 consecutive prolonged badminton matches on the shoulder strength and range of motion (ROM) of young players. Methods: Sixteen elite junior badminton players (12 males and 4 females; mean (SD): age 16.2 [0.8] years, body mass 63.5 [6.6] kg, height 173.2 [6.3] cm) participated in a cross-sectional study. Shoulder internal (IR)/external rotation (ER) ROM and IR/ER strength measures were conducted before and after 2 consecutive prolonged (ie, 35 min) matches and 12 hours after the second match. Results: After consecutive matches, IR strength of the dominant side and ER strength of the dominant and nondominant sides (effect size [ES] = 0.20–0.57) were reduced. Shoulder total ROM of the dominant side was decreased (ES = 0.80), while on the nondominant side, IR (ES = 0.66) was also decreased. After 12 hours, results showed decreased values in the IR/ER strength of the dominant side (ES = 0.36–1.00), as well as ER of both dominant and nondominant sides (ES = 0.30–0.59). IR ROM of the nondominant side (ES = 0.69) was also decreased. Conclusion: Present results showed that 2 consecutive matches on the same day with brief rest periods led to significant impairments in shoulder strength and ROM levels. These data can potentially elucidate the need for shoulder-specific training and recovery strategies prior to or during competitions.

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Anne-Marie Brouwer, Eli Brenner, and Jeroen B.J. Smeets

Before an aspect of a movement that is predicted by a control theory can be considered as evidence for that theory, it should be clear that this aspect is not the result of some other property of the movement. We investigate whether this condition is met in studies that claim to provide evidence for the tau-coupling theory. This theory proposes that moving targets are intercepted at a specified goal zone by maintaining a constant ratio between the tau (time to closure) of the gap between the hand and the goal zone and the tau of the gap between the hand and the moving target. In line with the theory, previous research has found a linear relationship between these two decreasing taus during the last part of such a movement. To investigate whether this linear relationship was a side-effect of smooth successful movements, we modeled smooth ballistic hand movements that were independent of the target's movement but led to successful interception. We found that the resulting taus of decreasing gaps were also related linearly. We conclude that this relationship cannot be considered as evidence for the tau-coupling theory.

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Tales C. Amorim, Mario R. Azevedo, and Pedro C. Hallal


To evaluate the association between the physical and social environment and physical activity (leisure-time and transport-related) in a population-based sample of adults.


Cross-sectional study including 972 adults (20−69 years) living in the urban area of Pelotas, Brazil. Physical activity was measured using the long International Physical Activity Questionnaire. Environmental variables were assessed using a modified version of the Neighborhood Environment Walkability Scale.


69.8% (95% CI = 66.9−72.7) and 51.9% (95% CI = 48.8−55.1) of the subjects did not reach 150 min/wk on leisure-time and transport-related physical activity, respectively. Subjects living near green areas were more likely to be active in leisure-time, as well as those who reported to live in safe neighborhoods. Transport-related physical activity was higher among individuals living in areas with garbage accumulation, and was lower among those living in neighborhoods which are difficult to walk or cycle due to traffic. Social support was strongly associated with leisure-time physical activity.


Safety investments, which are urgently required in Brazil, are likely to have a desirable side effect at increasing physical activity at the population level. Building enjoyable and safe public spaces for physical activity practice must be prioritized.

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Jake Pearson, David Rowlands, and Ruth Highet


Achilles tendinopathy is a common and often debilitating condition, and autologous blood injection is a promising treatment option.


To determine whether autologous blood injection added to standard management was effective in alleviating symptoms of Achilles tendinopathy.


A prospective randomized controlled trial.


Private sports medicine clinic.


33 patients (18 women, 15 men) of mean age 50 y (SD 9) with 40 cases of Achilles tendinopathy of mean duration of 11 mo (SD 7).


Participants were randomized to blind peritendinous autologous blood injection added to standard treatment (eccentric-loading exercises) or standard treatment alone for 12 wk.

Main Outcome Measure:

Victorian Institute of Sport Assessment for Achilles (VISA-A) score and ratings of discomfort during and after the injection were measured at baseline and 6 and 12 wk. Analytically derived effect-size thresholds of 5 (small) and 15 (moderate) VISA-A units were used as the reference values for clinical inference.


Improvements in VISA-A of 7.7 units (95%CL: ± 6.7) and 8.7 units (± 8.8) were observed in the treatment and control groups, respectively, at 6 wk relative to baseline, with no clear effect of blood injection. At 12 wk VISA-A score improved to 18.9 units (± 7.4) in the treatment group, revealing a blood-injection effect of 9.6 units (± 11.5), relative to a comparatively unchanged condition in control (9.4 units; ± 9.0). Predictors of response to treatment were unremarkable, and a 21% rate of postinjection flare was the only noteworthy side effect.


There is some evidence for small short-term symptomatic improvements with the addition of autologous blood injection to standard treatment for Achilles tendinopathy, although double-blinded studies with longer follow-up and larger sample size are required.

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Hermann Zbinden-Foncea, Isabel Rada, Jesus Gomez, Marco Kokaly, Trent Stellingwerff, Louise Deldicque, and Luis Peñailillo

caffeine intake, nor any side effect reported by the participants. Only diastolic pressure increased by 13.0%, but it remained within a normal physiological range. Our findings of the effects of isolated caffeine intake on jump-output variables are in agreement with the first reports of volleyball

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Katja Sonkeng

, AthletesVoice, and Unscriptd , basically rendering sports journalists and commentators inept, while allowing athletes to share their own voice, perspectives, and insights without the potential risk of being misinterpreted and taken out of context. As a side effect and likely enabled by the direct athlete

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Andrea Fusco, Christine Knutson, Charles King, Richard P. Mikat, John P. Porcari, Cristina Cortis, and Carl Foster

by multiplying the sRPE obtained after a training session by the total duration (in minutes) of the training session, including warm-up and cooldown. TL can be modified during the training cycle to increase or decrease fatigue depending on the phase of training and to minimize training side effect

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Shirley M. Bluethmann, Eileen Flores, Meghan Grotte, Jared Heitzenrater, Cristina I. Truica, Nancy J. Olsen, Christopher Sciamanna, and Kathryn H. Schmitz

but poorly understood AI side effect affecting up to 50% of AI users and continues to be a major reason for early AI discontinuation in BCS, especially in older patients with prior musculoskeletal conditions ( Burstein, 2007 ; Cahir et al., 2015 ). Despite the pervasiveness of AI-related arthralgias