Search

Compromised heat loss due to limited convection and evaporation can increase thermal strain. We aimed to determine the effectiveness of ice slurry ingestion to reduce thermal strain following hyperthermia in a state of compromised heat loss. Twelve healthy males (age: 25 ± 4y) underwent hot water immersion to elevate rectal temperature (Trec) by 1.82 ± 0.08°C on four occasions. In the subsequent 60-min of seated recovery, participants ingested either 6.8 g·kg-1 of ice slurry (-0.6°C) or control drink (37°C) in ambient conditions (21 ± 1°C, 39 ± 10% relative humidity), wearing either t-shirt and shorts (2 trials: ICE and CON) or a whole-body sweat suit (2 trials: ICE-SS and CON-SS). Trec and mean skin temperature (Tsk) were recorded and a two-compartment thermometry model of heat storage was calculated. Heat storage was lower in ICE compared with CON at 20-40min (p ≤ 0.044, d ≥ 0.88) and for ICE-SS compared with CON-SS at 40–60 min (p ≤ 0.012, d ≥ 0.93). Trec was lower in ICE compared with CON from 30-60min (p ≤ 0.034, d ≥ 0.65), with a trend for a reduced Trec in ICE-SS compared with CON-SS at 40min (p = 0.079, d = 0.60). A greater Tsk was found in ICE-SS and CON-SS compared with ICE and CON (p < 0.001, d ≥ 3.37). A trend for a lower Tsk for ICE compared with CON was found at 20-40min (p ≤ 0.099, d ≥ 0.53), no differences were found for ICE-SS vs CON-SS (p ≥ 0.554, d ≤ 0.43). Ice slurry ingestion can effectively reduce heat storage when heat loss through convection and evaporation is compromised, relevant to those wearing personal protective equipment or those with compromised sweat loss. Compromised heat loss delays the reduction in heat storage, possibly related to ice slurry ingestion not lowering Tsk. [ABSTRACT FROM AUTHOR]

The purpose of this study was to describe and explore an inertial measurement unit-based method to analyse drag forces and external power loss in wheelchair tennis, using standardised coast-down and 10 m sprint tests. Drag forces and power output were explored among different wheelchair-athlete combinations and playing conditions (tyre pressure, court-surface). Eight highly trained wheelchair tennis players participated in this study. Three inertial measurement units (IMUs) were placed on the frame and axes of the wheels of their wheelchair. All players completed a set of three standardised coast-down trials and two 10 m sprints with different tyre pressures on hardcourt surface. One athlete completed additional tests on a clay/grass tennis-court. Coast-down based drag forces of 4.8–7.2 N and an external power loss of 9.6–14.4 W at a theoretical speed of 2 m/s were measured on hardcourt surface. A higher tyre pressure led to lower drag forces during coast-down tests on hardcourt surface (Fr (4) = 10.7, p = 0.03). For the single athlete, there was an external power loss of 10.4, 15.6 and 49.4 W, respectively, for the hardcourt, clay and grass. The current prediction of power output was implemented during coast-down testing; unfortunately, the power prediction during 10 m sprints was difficult to accomplish. [ABSTRACT FROM AUTHOR]

Purpose: To examine the efficacy of per-cooling via ice slurry ingestion (ICE) in wheelchair tennis players exercising in the heat. Method: Eight wheelchair tennis players undertook sprints (4 sets of 10 × 5 s over 40 min) in a hot environment (∼32 °C), interspersed by 3 boluses of 2.67 g·kg (6.8 g·kg total) ICE or drinking temperate water (control condition). Athletes performed an on-court test of repeated sprint ability (20 × 20 m) in temperate conditions immediately before and 20 minutes after the heat exposure, and time to complete each sprint as well as intermediate times were recorded. Gastrointestinal and weighted mean skin and forehead temperatures were collected throughout the heat exposure, as were thermal sensation, heart rate, and blood lactate concentration. Sweat rate was calculated from body mass changes and fluid/ice intakes. Results: Compared with the control condition, ICE resulted in a significantly lower gastrointestinal temperature (95% CI, 0.11–0.17 °C; P <.001), forehead temperature (0.58–1.06 °C; P <.001), thermal sensation (0.07–0.50 units; P =.017), and sweat rate (0.06–0.46 L·h−1; P =.017). Skin temperature, heart rate, and blood lactate concentration were not significantly different between conditions (P ≥.598). There was no overall change preheating to postheating (P ≥.114) or an effect of condition (P ≥.251) on repeated sprint times. Conclusions: ICE is effective at lowering objective and subjective thermal strain when consumed between sets of repeated wheelchair sprints in the heat. However, ICE has no effect on on-court repeated 20-m sprint performance. [ABSTRACT FROM AUTHOR]

Purpose: To compare the effects of typical competition versus high-intensity intermittent warm-up (WU) on thermoregulatory responses and repeated sprint performance during wheelchair rugby game play. Methods: An intermittent sprint protocol (ISP) simulating the demands of wheelchair rugby was performed by male wheelchair rugby players (7 with cervical spinal cord injury [SCI] and 8 without SCI) following 2 WU protocols. These included a typical competition WU (control) and a WU consisting of high-intensity efforts (INT). Core temperature (Tcore), thermal sensation, and thermal comfort were recorded. Wheelchair performance variables associated to power, speed, and fatigue were also calculated. Results: During the WU, Tcore was similar between conditions for both groups. During the ISP, a higher Tcore was found for SCI compared to NON-SCI (38.1 [0.3] vs 37.7 [0.3] °C: P =.036, d = 0.75), and the SCI group experienced a higher peak Tcore for INT compared with control (39.0 [0.4] vs 38.6 [0.6] °C; P =.004). Peak Tcore occurred later in the ISP for players with SCI (96 [5.8] vs 48 [2.7] min; P <.001). All players reported a higher thermal sensation and thermal comfort following INT (P <.001), with no differences between conditions throughout the ISP. No significant differences were found in wheelchair performance variables during the ISP between conditions (P ≥.143). Conclusions: The high-INT WU increased thermal strain in the SCI group during the ISP, potentially due to increased metabolic heat production and impaired thermoregulation, while not impacting on repeated sprint performance. It may be advisable to limit high-INT bouts during a WU in players with SCI to mitigate issues related to hyperthermia in subsequent performance. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate the tracking of within-athlete changes in criterion measures of whole-body fat percentage (BF%; dual-energy X-ray absorptiometry) with skinfold thickness (Σ 4, 6, or 8) in wheelchair basketball players. Methods: Dual-energy X-ray absorptiometry-derived whole BF% and Σ 4, 6, or 8 skinfolds were obtained at 5 time points over 15 months (N = 16). A linear mixed model with restricted maximum likelihood (random intercept, with identity covariance structure) to derive the within-athlete prediction error for predicting criterion BF% from Σ skinfolds was used. This prediction error allowed us to evaluate how well a simple measure of the Σ skinfolds could track criterion changes in BF %; that is, the authors derived the change in Σ skinfolds that would have to be observed in an individual athlete to conclude that a substantial change in criterion BF% had occurred. Data were log-transformed prior to analysis. Results: The Σ 8 skinfolds was the most precise practical measure for tracking changes in BF%. For the monitoring of an individual player, a change in Σ 8 skinfolds by a factor of greater than 1.28 (multiply or divide by 1.28) is associated with a practically meaningful change in BF% (≥1 percentage point). Conclusions: The Σ 8 skinfolds can track changes in BF% within individuals with reasonable precision, providing a useful field monitoring tool in the absence of often impractical criterion measures. [ABSTRACT FROM AUTHOR]

The purpose of this study was to examine the interrater reliability of a new evidence-based classification system for Para Va'a. Twelve Para Va'a athletes were classified by three classifier teams each consisting of a medical and a technical classifier. Interrater reliability was assessed by calculating intraclass correlation for the overall class allocation and total scores of trunk, leg, and on-water test batteries and by calculating Fleiss's kappa and percentage of total agreement in the individual tests of each test battery. All classifier teams agreed with the overall class allocation of all athletes, and all three test batteries exhibited excellent interrater reliability. At a test level, agreement between classifiers was almost perfect in 14 tests, substantial in four tests, moderate in four tests, and fair in one test. The results suggest that a Para Va'a athlete can expect to be allocated to the same class regardless of which classifier team conducts the classification. [ABSTRACT FROM AUTHOR]

Purpose: Paratriathletes may display impairments in autonomic (sudomotor and/or vasomotor function) or behavioral (drinking and/or pacing of effort) thermoregulation. As such, this study aimed to describe the thermoregulatory profile of athletes competing in the heat. Methods: Core temperature (Tc) was recorded at 30-second intervals in 28 mixed-impairment paratriathletes during competition in a hot environment (air temperature = 33°C, relative humidity = 35%–41%, and water temperature = 25°C–27°C), via an ingestible temperature sensor (BodyCap e-Celsius). Furthermore, in a subset of 9 athletes, skin temperature was measured. Athletes' wetsuit use was noted while heat illness symptoms were self-reported postrace. Results: In total, 22 athletes displayed a Tc ≥ 39.5°C with 8 athletes ≥40.0°C. There were increases across the average Tc for swim, bike, and run sections (P ≤.016). There was no change in skin temperature during the race (P ≥.086). Visually impaired athletes displayed a significantly greater Tc during the run section than athletes in a wheelchair (P ≤.021). Athletes wearing a wetsuit (57% athletes) had a greater Tc when swimming (P ≤.032), whereas those reporting heat illness symptoms (57% athletes) displayed a greater Tc at various time points (P ≤.046). Conclusions: Paratriathletes face significant thermal strain during competition in the heat, as evidenced by high Tc, relative to previous research in able-bodied athletes and a high incidence of self-reported heat illness symptomatology. Differences in the Tc profile exist depending on athletes' race category and wetsuit use. [ABSTRACT FROM AUTHOR]

Paralympic athletes may be at increased risk for exertional heat illness (EHI) due to reduced thermoregulatory ability as a consequence of their impairment. This study investigated the occurrence of heat-stress related symptoms and EHI, and the use of heat mitigation strategies in Paralympic athletes, both in relation to the Tokyo 2020 Paralympic Games and previous events. Paralympic athletes competing in Tokyo 2020 were invited to complete an online survey five weeks prior to the Paralympics and up to eight weeks after the Games. 107 athletes (30 [24–38] years, 52% female, 20 nationalities, 21 sports) completed the survey. 57% of respondents had previously experienced heat-stress related symptoms, while 9% had been medically diagnosed with EHI. In Tokyo, 21% experienced at least one heat-stress related symptom, while none reported an EHI. The most common symptom and EHI were, respectively, dizziness and dehydration. In preparation for Tokyo, 58% of respondents used a heat acclimation strategy, most commonly heat acclimatization, which was more than in preparation for previous events (45%; P = 0.007). Cooling strategies were used by 77% of athletes in Tokyo, compared to 66% during past events (P = 0.18). Cold towels and packs were used most commonly. Respondents reported no medically-diagnosed EHIs during the Tokyo 2020 Paralympic Games, despite the hot and humid conditions in the first seven days of competition. Heat acclimation and cooling strategies were used by the majority of athletes, with heat acclimation being adopted more often than for previous competitions. [ABSTRACT FROM AUTHOR]

The purpose of this review was to compare all intervention modalities aimed at increasing skeletal muscle mass (SMM) in the paralysed limbs of persons with chronic (>1-year post-injury), motor complete spinal cord injury (SCI). A systematic review of EMBASE, MEDLINE, Scopus, and SPORTDiscus databases was conducted from inception until December 2021. Published intervention studies aimed to increase SMM (measured by magnetic resonance imaging, computed tomography, ultrasound, muscle biopsy, or lean soft tissue mass by dual X-ray absorptiometry) in the paralysed limbs of adults (>18 years) with SCI were included. Fifty articles were included that, overall, demonstrated a high risk of bias. Studies were categorised into six groups: neuromuscular electrical stimulation (NMES) with and without external resistance, functional electrical stimulation cycling, walking- and standing-based interventions, pharmacological treatments, and studies that compared or combined intervention modalities. Resistance training (RT) using NMES on the quadriceps produced the largest and most consistent increases in SMM of all intervention modalities. Current evidence suggests that clinical practise aiming to increase SMM in the paralysed limbs of persons with motor complete SCI should perform NMES-RT. However, more high-quality randomised control trials are needed to determine how training variables, such as exercise volume and intensity, can be optimised for increasing SMM. Persons with spinal cord injury (SCI) experience severe reductions in skeletal muscle mass (SMM) post-injury, which may exacerbate their risk of obesity and metabolic disease. Out of all exercise and non-exercise-based interventions, this systematic review shows that neuromuscular electrical stimulation-based resistance training demonstrates the most robust and consistent evidence for increasing skeletal muscle mass in the paralysed limbs of adults with motor complete spinal cord injury. The findings from this review can be used to inform evidence-based practise for exercise practitioners, as well as direct future research focused on increasing muscle mass in this population. [ABSTRACT FROM AUTHOR]

Purpose: In able-bodied athletes, several hormonal, immunological, and psychological parameters are commonly assessed in response to intensified training due to their potential relationship to acute fatigue and training/nontraining stress. This has yet to be studied in Paralympic athletes. Methods: A total of 10 elite paratriathletes were studied for 5 wk around a 14-d overseas training camp whereby training load was 137% of precamp levels. Athletes provided 6 saliva samples (1 precamp, 4 during camp, and 1 postcamp) for cortisol, testosterone, and secretory immunoglobulin A; weekly psychological questionnaires (Profile of Mood State [POMS] and Recovery-Stress Questionnaire for Athletes [RESTQ-Sport]); and daily resting heart rate and subjective wellness measures including sleep quality and quantity. Results: There was no significant change in salivary cortisol, testosterone, cortisol Testosterone ratio, or secretory immunoglobulin A during intensified training (P≥.090). Likewise, there was no meaningful change in resting head rate or subjective wellness measures (P ≥ .079). Subjective sleep quality and quantity increased during intensified training (P ≤ .003). There was no significant effect on any POMS subscale other than lower anger (P = .049), whereas there was greater general recovery and lower sport and general stress from RESTQ-Sport (≤ .015). Conclusions: There was little to no change in parameters commonly associated with the fatigued slate, which may relate to the training-camp setting minimizing external life stresses and the careful management of training loads from coaches. This is the first evidence of such responses in Paralympic athletes. [ABSTRACT FROM AUTHOR]

Purpose: To determine the effect of trunk and arm impairments on physical and technical performance during wheelchair rugby (WR) competition. Methods: Thirty-one highly trained WR players grouped according to their trunk (no trunk [NT]; some trunk [T] function) and arm impairments (poor, moderate, and good arm function) participated in 5 WR matches. Players' physical (wheelchair mobility) and technical (ball handling) activities were analyzed using an indoor tracking system and video analysis, respectively. Results: Trunk impairment explained some of the variance in physical (10.6–23.5%) and technical (16.2–33.0%) performance. T covered more distance, had more possession, scored more goals, and received and made more passes yet spent less time at low speeds and performed fewer inbounds than NT (≤.05). Arm impairment explained some of the variance in all physical (16.7–47.0%) and the majority of technical (13.1–53.3%) performance measures. Moderate and good arm function covered more distance, reached higher peak speeds, spent more time in higher speed zones, scored more goals, had more possession, and received and made more passes, with a higher percentage of 1-handed and long passes, than poor arm function. Good arm function also received more passes and made a higher percentage of 1-handed passes and defensive blocks than moderate arm function (P ≤.05). Conclusions: Arm impairment affects a greater number of physical and technical measures of performance specific to WR than trunk impairment during competition. Having active finger function (good arm function) yielded no further improvements in physical performance but positively influenced a small number of technical skills. [ABSTRACT FROM AUTHOR]

Purpose: To gain an exploratory insight into the relation between training load (TL), salivary secretory immunoglobulin A (sIgA), and upper respiratory tract illness (URI) in elite paratriathletes. Methods: Seven paratriathletes were recruited. Athletes provided weekly saliva samples for the measurement of sIgA over 23 consecutive weeks (February to July) and a further 11 consecutive weeks (November to January). sIgA was compared to individuals' weekly training duration, external TL, and internal TL, using time spent in predetermined heart-rate zones. Correlations were assessed via regression analyses. URI was quantified via weekly self-report symptom questionnaire. Results: There was a significant negative relation between athletes' individual weekly training duration and sIgA secretion rate (P =.028), with changes in training duration accounting for 12.7% of the variance (quartiles: 0.2%, 19.2%). There was, however, no significant relation between external or internal TL and sIgA parameters (P ≥.104). There was no significant difference in sIgA when URI was present or not (101% vs 118% healthy median concentration; P ≥.225); likewise, there was no difference in sIgA when URI occurred within 2 wk of sampling or not (83% vs 125% healthy median concentration; P ≥.120). Conclusions: Paratriathletes' weekly training duration significantly affects sIgA secretion rate, yet the authors did not find a relation between external or internal TL and sIgA parameters. Furthermore, it was not possible to detect any link between sIgA and URI occurrence, which throws into question the potential of using sIgA as a monitoring tool for early detection of illness. [ABSTRACT FROM AUTHOR]