Context: The lower quarter Y-Balance Test (YBT-LQ) is associated with injury risk; however, ankle range of motion impacts YBT-LQ. Arch height and foot sensation impact static balance, but these characteristics have not yet been evaluated relative to YBT-LQ. Objective: Determine if arch height index (AHI), forefoot sensation (SEN), and ankle dorsiflexion predict YBT-LQ composite score (CS). Design: Descriptive cohort. Setting: Athletic training laboratory. Participants: Twenty general population (14 females and 6 males; mean [SD]: age 35  y, weight 70.02 [16.76] kg, height 1.68 [0.12] m) participated in this study. Interventions: AHI measurement system assessed arch height in 10% (AHI10) and 90% (AHI90) weight-bearing. Two-point discrim-a-gon discs assessed sensation (SEN) at the plantar great toe, third and fifth metatarsal heads. Biplane goniometer and weight-bearing lunge tests were used to measure static and weight-bearing dorsiflexion, respectively. The YBT-LQ assessed dynamic single-leg balance. Results: For right-limb dynamic single-leg balance, AHI90 and SEN were included in the final sequential prediction equation; however, neither model significantly (P = .052 and .074) predicted variance in YBT-LQ CS. For left-limb dynamic single-leg balance, both SEN and weight-bearing lunge test were included in the final sequential prediction equation. The regression model (SEN and weight-bearing lunge test) significantly (P = .047) predicted 22% of the variance in YBT-LQ CS. Conclusions: This study demonstrates that foot characteristics may play a role in YBT-LQ CS. The authors did not assess limb dominance in this study; therefore, the authors are unable to determine which limb would be the stance versus kicking limb. However, altered SEN and weight-bearing dorsiflexion appear to be contributing factors to YBT-LQ CS.
You are looking at 161 - 170 of 25,288 items
Nicole J. Chimera and Mallorie Larson
Bryan C. Clift
Across North American cities, emerging forms of urban governance from the 1970s produced forms of racialized, visualized, and spatialized urban poverty. Attempts to revitalize, recast, and spectacularize the urban environment left cities with vexing questions about what should be done with homeless people and also what homeless people should be doing. Amidst the rolling back of State social welfare policies and provision (Peck & Tickell, 2002), creative, informal, communal, or non-governmental initiatives have emerged in response to urban poverty and homelessness. One such organization is Back on My Feet, a national, not-for-profit organization that partners with homeless and addiction recovery facilities, which strives to utilize running as a means of empowerment. This ethnographic inquiry speaks to the ways in which the social practice of running amongst those housed in a temporary recovery facility is imbricated with their lifestyles and identities, an urban context, and homeless discourses and stigmas. It is illustrative of how the rhetoric of “recovery” yokes together the entrepreneurial ethos of neoliberalism with the management of homeless people.
Matheus Lima Oliveira, Isabela Christina Ferreira, Kariny Realino Ferreira, Gabriela Silveira-Nunes, Michelle Almeida Barbosa and Alexandre Carvalho Barbosa
Context: Strength assessment is essential to prescribe exercise in sports and rehabilitation. Low-cost valid equipment may allow continuous monitoring of training. Objective: To examine the validity of a very low-cost hanging scale by comparing differences in the measures of peak force to a laboratory grade load cell during shoulder abduction, flexion, extension, and internal and external rotations. Design: Analytical study. Participants: Thirty-two healthy subjects (18 women, age 26  y, height 172  cm, mass 69  kg, body mass index 23  kg/m2). Main Outcome Measures: The dependent variable was the maximal peak force (in kilogram-force). The independent variable was the instrument (laboratory grade load cell and hanging scale). Results: No differences were observed while comparing the results. The intraclass correlation coefficients1,1 ranged from .96 to .99, showing excellent results. The Cronbach alpha test also returned >.99 for all comparisons. The SEM ranged from 0.02 to 0.04 kgf, with an averaged SD from 0.24 to 0.38 kgf. The correlation was classified as high for all tested movements (r > .99; P < .001), with excellent adjusted coefficients of determination (.96 < r 2 < .99). Bland–Altman results showed high levels of agreement with bias ranging from 0.27 to 0.48. Conclusions: Hanging scale provides valid measures of isometric strength with similar output measures as laboratory grade load cell.
Benita J. Lalor, Shona L. Halson, Jacqueline Tran, Justin G. Kemp and Stuart J. Cormack
Purpose: To assess relationships between objective sleep characteristics, external training loads, and subjective ratings of well-being in elite Australian football (AF) players. Methods: A total of 38 elite male AF players recorded objective sleep characteristics over a 15-day period using an activity monitor. External load was assessed during main field sessions, and ratings of well-being were provided each morning. Canonical correlation analysis was used to create canonical dimensions for each variable set (sleep, well-being, and external load). Relationships between dimensions representing sleep, external load, and well-being were quantified using Pearson r. Results: Canonical correlations were moderate between pretraining sleep and external training load (r = .32–.49), pretraining sleep and well-being (r = .32), and well-being and posttraining sleep (r = .36). Moderate to strong correlations were observed between dimensions representing external training load and posttraining sleep (r = .31–.67), and well-being and external training load (r = .32–.67). Player load and Player load 2D (PL2D) showed the greatest association to pretraining and posttraining objective sleep characteristics and well-being. Fragmented sleep was associated with players completing the following training with a higher PL2D. Conclusions: Maximum speed, player load, and PL2D were the common associations between objective sleep characteristics and well-being in AF players. Improving pretraining sleep quality and quantity may have a positive impact on AF players’ well-being and movement strategy during field sessions. Following training sessions that have high maximum speed and PL2D, the increased requirement for sleep should be considered by ensuring that subsequent sessions do not start earlier than required.
Christopher John Stevens, Megan L. Ross, Julien D. Périard, Brent S. Vallance and Louise M. Burke
Purpose: The core temperature responses during exercise and effects of different cooling strategies on endurance performance under heat stress have been investigated in recreational athletes. This investigation aimed to determine peak rectal temperatures during elite racewalking competitions and to detail any cooling strategies used. Methods: Rectal temperature was measured in 14 heat-adapted elite/preelite race walkers (9 females) via a telemetric capsule across 4 outdoor events, including the 2018 Commonwealth Games (race 1: 20 km, 25°C, 74% relative humidity [RH], n = 2) and 3 International Association of Athletics Federations–sanctioned 10-km events (race 2: 19°C, 34% RH, n = 2; race 3: 29°C, 47% RH, n = 14; and race 4: 23°C, 72% RH, n = 11). All athletes completed race 3, and a subsample completed the other events. Their use of cooling strategies and symptoms of heat illness were determined. Results: Peak rectal temperatures >40°C were observed in all events. The highest rectal temperature observed during an event was 41.2°C. These high rectal temperatures were observed without concomitant heat illness, with the exception of cramping in one athlete during race 1. The rectal temperatures tended to reach a steady state in the second half of the 20-km event, but no steady state was observed in the 10-km events. The athletes used cooling strategies in race 1 only, implementing different combinations of cold-water immersion, ice-slurry ingestion, ice-towel application, ice-vest application, and facial water spraying. Conclusions: Elite/preelite race walkers experience rectal temperatures >40°C during competition despite only moderate-warm conditions, and even when precooling and midcooling strategies are applied.
David N. Borg, Ian B. Stewart, John O. Osborne, Christopher Drovandi, Joseph T. Costello, Jamie Stanley and Geoffrey M. Minett
Purpose: To examine the effects of daily cold- and hot-water recovery on training load (TL) during 5 days of heat-based training. Methods: Eight men completed 5 days of cycle training for 60 minutes (50% peak power output) in 4 different conditions in a block counter-balanced-order design. Three conditions were completed in the heat (35°C) and 1 in a thermoneutral environment (24°C; CON). Each day after cycling, participants completed 20 minutes of seated rest (CON and heat training [HT]) or cold- (14°C; HTCWI) or hot-water (39°C; HTHWI) immersion. Heart rate, rectal temperature, and rating of perceived exertion (RPE) were collected during cycling. Session-RPE was collected 10 minutes after recovery for the determination of session-RPE TL. Data were analyzed using hierarchical regression in a Bayesian framework; Cohen d was calculated, and for session-RPE TL, the probability that d > 0.5 was also computed. Results: There was evidence that session-RPE TL was increased in HTCWI (d = 2.90) and HTHWI (d = 2.38) compared with HT. The probabilities that d > 0.5 were .99 and .96, respectively. The higher session-RPE TL observed in HTCWI coincided with a greater cardiovascular (d = 2.29) and thermoregulatory (d = 2.68) response during cycling than in HT. This result was not observed for HTHWI. Conclusion: These findings suggest that cold-water recovery may negatively affect TL during 5 days of heat-based training, hot-water recovery could increase session-RPE TL, and the session-RPE method can detect environmental temperature-mediated increases in TL in the context of this study.
Mohamed Romdhani, Nizar Souissi, Yassine Chaabouni, Kacem Mahdouani, Tarak Driss, Karim Chamari and Omar Hammouda
Purpose: To investigate the effects of napping after partial sleep deprivation (PSD) on reaction time, mood, and biochemical response to repeated-sprint exercise in athletes. Methods: Nine male judokas performed 4 test sessions in a counterbalanced and randomized order. Participants accomplished 1 control session after a normal sleep night (NSN) and 3 after PSD with (1) no nap, (2) ∼20-min nap (N20), and (3) ∼90-min nap (N90) opportunities. Test sessions included the running-based anaerobic sprint test, reaction time, Hooper index, and Epworth Sleepiness Scale. Muscle-damage biomarkers and antioxidant status were evaluated before and after exercise. Results: PSD decreased maximum (P < .001, d = 1.12), mean (P < .001, d = 1.33), and minimum (P < .001, d = 1.15) powers compared with NSN. However, N20 and N90 enhanced maximum power compared with PSD (P < .05, d = 0.54; P < .001, d = 1.06, respectively). Minimum power and mean power increased only after N90 (P < .001, d = 1.63; P < .001, d = 1.16, respectively). Epworth Sleepiness Scale increased after PSD (P < .001, d = 0.86) and decreased after N20 (P < .001, d = 1.36) and N90 (P < .001, d = 2.07). N20 reduced multiple-choice reaction time (P < .001, d = 0.61). Despite performance decrement, PSD increased postexercise aspartate aminotransferase (P < .001, d = 4.16) and decreased glutathione peroxidase (P < .001, d = 4.02) compared with NSN. However, the highest performances after N90 were accompanied with lesser aspartate aminotransferase (P < .001, d = 1.74) and higher glutathione peroxidase (P < .001, d = 0.86) compared with PSD. Conclusions: Napping could be preventive against performance degradation caused by sleep loss. A short nap opportunity could be more beneficial when the subsequent effort is brief and requires frequent decision making. However, a longer nap opportunity could be preventive against muscle and oxidative damage, even for higher performances.
Sarah J. Willis, Grégoire P. Millet and Fabio Borrani
Purpose: To assess tissue oxygenation, along with metabolic and physiological responses during blood flow restriction (BFR, bilateral vascular occlusion) and systemic hypoxia conditions during submaximal leg- versus arm-cycling exercise. Methods: In both legs and arms, 4 randomized sessions were performed (normoxia 400 m, fraction of inspired oxygen [FIO2] 20.9% and normobaric hypoxia 3800 m, FIO2 13.1% [0.1%]; combined with BFR at 0% and 45% of resting pulse elimination pressure). During each session, a single 6-minute steady-state submaximal exercise was performed to measure physiological changes and oxygenation (near-infrared spectroscopy) of the muscle tissue in both the vastus lateralis (legs) and biceps brachii (arms). Results: Total hemoglobin concentration ([tHb]) was 65% higher (P < .001) in arms versus legs, suggesting that arms had a greater blood perfusion capacity than legs. Furthermore, there were greater changes in tissue blood volume [tHb] during BFR compared with control conditions (P = .017, F = 5.45). The arms elicited 7% lower tissue saturation (P < .001) and were thus more sensitive to the hypoxia-induced reduction in oxygen supply than legs, no matter the condition. This indicates that legs and arms may elicit different regulatory hemodynamic mechanisms (ie, greater blood flow in arms) for limiting the decreased oxygen delivery during exercise with altered arterial oxygen content. Conclusions: The combination of BFR and/or hypoxia led to increased [tHb] in both limbs likely due to greater vascular resistance; further, arms were more responsive than legs. This possibly influences the maintenance of oxygen delivery and enhances perfusion pressure, suggesting greater vascular reactivity in arms than in legs.
Paulo H.C. Mesquita, Emerson Franchini, Marco A. Romano-Silva, Guilherme M. Lage and Maicon R. Albuquerque
Purpose: To investigate the effects of anodal transcranial direct current stimulation (a-tDCS) on the aerobic performance, heart rate (HR), and rating of perceived exertion (RPE) of highly trained taekwondo athletes. Methods: Twelve (8 men and 4 women) international/national-level athletes received a-tDCS or sham treatment over the M1 location in a randomized, single-blind crossover design. The stimulation was delivered at 1.5 mA for 15 min using an extracephalic bihemispheric montage. Athletes performed the progressive-specific taekwondo test 10 min after stimulation. HR was monitored continuously during the test, and RPE was registered at the end of each stage and at test cessation. Results: There were no significant differences between sham and a-tDCS in time to exhaustion (14.6 and 14.9, respectively, P = .53, effect size = 0.15) and peak kicking frequency (52 and 53.6, respectively, P = .53, effect size = 0.15) or in HR (P > .05) and RPE responses (P > .05). Conclusions: Extracephalic bihemispheric a-tDCS over M1 did not influence the aerobic performance of taekwondo athletes or their psychophysiological responses, so athletes and staff should be cautious when using it in a direct-to-consumer manner.
Filipe M. Clemente, Ana F. Silva, Cain C.T. Clark, Daniele Conte, João Ribeiro, Bruno Mendes and Ricardo Lima
Purpose: The purposes of this study were to (1) analyze the variations of acute and chronic training load and well-being measures during 3 periods of the season (early, mid, and end) and (2) test the associations between weekly training load and well-being measures during different periods of the season. Methods: Thirteen professional volleyball players from a team competing in the Portuguese Volleyball First Division (age 31.0 [5.0] y) were monitored during an entire season. Weekly acute (wAL) and chronic load (wCL), acute to chronic workload ratio (wACWL), and training monotony (wTM) were calculated during all weeks of the season. The weekly values of muscle soreness (wDOMS), stress (wStress), fatigue (wFatigue), sleep (wSleep), and Hooper index (wHI) were also obtained across the season. Results: The midseason had meaningfully low values of wAL (−26.9%; effect size [ES]: −1.12) and wCL (−28.0%; ES: −2.81), and greater values of wACWL (+38.9%; ES: 2.81) compared with early season. The wCL (+10.6%; ES: 0.99), wStress (44.6%; ES: 0.87), and wHI (29.0%; ES: 0.62) were meaningfully greater during the end of season than in midseason. Overall, wAL presented very large correlations with wDOMS (r = .80), wSleep (r = .72), and wFatigue (r = .82). Conclusions: The results of this study suggest that the load was meaningfully higher during early season; however, stress was higher during the final stages of the season. Overall, it was also found that the acute load is more highly correlated with well-being status and its variations than chronic load or training monotony.