Environmental and Psychophysical Heat Stress in Adolescent Tennis Athletes

2021 ◽  
pp. 1-6
Author(s):  
Maria Misailidi ◽  
Konstantinos Mantzios ◽  
Christos Papakonstantinou ◽  
Leonidas G. Ioannou ◽  
Andreas D. Flouris
Keyword(s):  
Perceived Exertion ◽  
Thermal Sensation ◽  
Meteorological Data ◽  
Urine Specific Gravity ◽  
Match Play ◽  
Warm Up ◽  
Junior Tennis ◽  
And Performance ◽  
C 30 ◽  
Head Neck

Purpose: We investigated the environmental conditions in which all outdoor International Tennis Federation (ITF) junior tournaments (athlete ages: <18 y) were held during 2010–2019. Thereafter, we performed a crossover trial (ClinicalTrials.gov: NCT04197375) assessing the efficacy of head–neck precooling for mitigating the heat-induced psychophysical and performance impacts on junior athletes during tennis match play. Methods: ITF junior tournament information was collected. We identified meteorological data from nearby (13.6 [20.3] km) weather stations for 3056 (76%) tournaments. Results: Overall, 30.1% of tournaments were held in hot (25°C–30°C wet-bulb globe temperature [WBGT]; 25.9%), very hot (30°C–35°C WBGT; 4.1%), or extremely hot (>35°C WBGT; 0.1%) conditions. Thereafter, 8 acclimatized male junior tennis athletes (age = 16.0 [0.9] y; height = 1.82 [0.04] m; weight = 71.3 [11.1] kg) were evaluated during 2 matches: one with head–neck precooling (27.7°C [2.2°C] WBGT) and one without (27.9°C [1.8°C] WBGT). Head–neck precooling reduced athletes’ core temperature from 36.9°C (0.2°C) to 36.4°C (0.2°C) (P = .001; d = 2.4), an effect reduced by warm-up. Head–neck precooling reduced skin temperature (by 0.3°C [1.3°C]) for the majority of the match and led to improved (P < .05) perceived exertion (by 13%), thermal comfort (by 14%), and thermal sensation (by 15%). Muscle temperature, heart rate, body weight, and urine specific gravity remained unaffected (P ≥ .05; d < 0.2). Small or moderate improvements were observed in most performance parameters assessed (d = 0.20–0.79). Conclusions: Thirty percent of the last decade’s ITF junior tournaments were held in hot, very hot, or extremely hot conditions (25°C–36°C WBGT). In such conditions, head–neck precooling may somewhat lessen the physiological and perceptual heat strain and lead to small to moderate improvements in the match-play performance of adolescent athletes.

Endurance Cyclist Fluid Intake, Hydration Status, Thirst, and Thermal Sensations: Gender Differences

2016 ◽  
Vol 26 (2) ◽  
pp. 161-167 ◽  
Author(s):  
Lawrence E. Armstrong ◽  
Evan C. Johnson ◽  
Amy L. McKenzie ◽  
Lindsay A. Ellis ◽  
Keith H. Williamson
Keyword(s):  
Gender Differences ◽  
Body Mass ◽  
Perceived Exertion ◽  
Thermal Sensation ◽  
Drinking Behavior ◽  
Field Investigation ◽  
Urine Specific Gravity ◽  
Hydration Status ◽  
Exercise Time ◽  
Body Mass Change

This field investigation assessed differences (e.g., drinking behavior, hydration status, perceptual ratings) between female and male endurance cyclists who completed a 164-km event in a hot environment (35 °C mean dry bulb) to inform rehydration recommendations for athletes. Three years of data were pooled to create 2 groups of cyclists: women (n = 15) and men (n = 88). Women were significantly smaller (p < .001) than men in height (166 ± 5 vs. 179 ± 7 cm), body mass (64.6 ± 7.3 vs. 86.4 ± 12.3 kg), and body mass index (BMI; 23.3 ± 1.8 vs. 26.9 ± 3.4) and had lower preevent urinary indices of hydration status, but were similar to men in age (43 ± 7 years vs. 44 ± 9 years) and exercise time (7.77 ± 1.24 hr vs. 7.23 ± 1.75 hr). During the 164-km ride, women lost less body mass (−0.7 ± 1.0 vs. −1.7 ± 1.5 kg; −1.1 ± 1.6% vs. −1.9 ± 1.8% of body weight; p < .005) and consumed less fluid than men (4.80 ± 1.28 L vs. 5.59 ± 2.13 L; p < .005). Women consumed a similar volume of fluid as men, relative to body mass (milliliters/kilogram). To control for performance and anthropomorphic characteristics, 15 women were pair-matched with 15 men on the basis of exercise time on the course and BMI; urine-specific gravity, urine color, and body mass change (kilograms and percentage) were different (p < .05) in 4 of 6 comparisons. No gender differences were observed for ratings of thirst, thermal sensation, or perceived exertion. In conclusion, differences in relative fluid volume consumed and hydration indices suggest that professional sports medicine organizations should consider gender and individualized drinking plans when formulating pronouncements regarding rehydration during exercise.

Hydrogen Rich Water Improved Ventilatory, Perceptual and Lactate Responses to Exercise

2019 ◽  
Vol 40 (14) ◽  
pp. 879-885 ◽  
Author(s):  
Michal Botek ◽  
Jakub Krejčí ◽  
Andrew J. McKune ◽  
Barbora Sládečková ◽  
Nenad Naumovski
Keyword(s):  
Blood Lactate ◽  
Perceived Exertion ◽  
Ratings Of Perceived Exertion ◽  
Exercise Protocol ◽  
Warm Up ◽  
Ventilatory Equivalent ◽  
Lower Blood ◽  
And Performance ◽  
Exercise Induced ◽  
Double Blinded

AbstractThe potential anti-fatigue and performance benefits of hydrogen rich water (HRW) have resulted in increased research interest over the past 5 years. The aim of this study was to assess physiological and perceptual responses to an incremental exercise protocol after administration of 600 ml HRW within 30 min before exercise. This randomized, double blinded placebo-controlled cross over study included twelve healthy males aged 27.1±4.9 years. The exercise protocol consisted of a 10 min warm-up at 1.0 W.kg−1, followed by 8 min at 2.0, 3.0, and 4.0 W.kg−1, respectively. Cardio-respiratory variables, lactate and ratings of perceived exertion (RPE) were assessed in the last minute of each step. A significantly lower blood lactate was found with HRW (4.0±1.6 and 8.9±2.2 mmol.l−1) compared to Placebo (5.1±1.9 and 10.6±3.0 mmol.l−1) at 3.0, and 4.0 W.kg−1, respectively. Ventilatory equivalent for oxygen and RPE exhibited significantly lower values with HRW (32.3±7.2, and 17.8±1.2 points, respectively) compared to Placebo (35.0±8.4, and 18.5±0.8 points, respectively) at 4 W.kg−1. To conclude, acute pre-exercise supplementation with HRW reduced blood lactate at higher exercise intensities, improved exercise-induced perception of effort, and ventilatory efficiency.

Warm-Up Practices in Elite Snowboard Athletes

2012 ◽  
Vol 7 (3) ◽  
pp. 295-297 ◽  
Author(s):  
Ben C. Sporer ◽  
Anita Cote ◽  
Gordon Sleivert
Keyword(s):  
Thermal Sensation ◽  
Activity Patterns ◽  
Start Time ◽  
Optimal Length ◽  
Warm Up ◽  
Observational Design ◽  
Physiological Impact ◽  
Barriers And Challenges ◽  
And Performance ◽  
Future Work

Purpose:The purpose of this project was to observe current warm-up practices in snowboard athletes and evaluate their physiological impact before competition.Methods:An observational design was used to monitor 4 athletes (2 female) at an Open National Snowboard Cross Championships. Activity patterns, core temperature, heart rate (HR), and time between warm-up and competition were measured. Athlete ratings of thermal comfort (TC) and thermal sensation (TS) were recorded before competition.Results:Significant barriers and challenges to an optimal warm-up included delays, environment, and logistics. Time gaps between structured warm-up and competition start time were in excess of 1 h (median = 68.8 min). Median average HR for 10 min (HR10) did not exceed 120 beats/min in the hour preceding competition, suggesting a suboptimal warmup intensity. Athletes rated their TC between comfortable and slightly uncomfortable and TS as neutral to slightly warm before the start of qualifications and finals.Conclusions:The observations of this project suggest significant gaps in current warm-up strategies used in snowboarding. These include inadequate general aerobic warm-up (based on intensity and duration), excessive time between warm-up and competition, and lack of a consistent and structured warm-up protocol. Future work is needed to evaluate the effectiveness of different warm-up strategies on muscle temperature and performance while determining the optimal length of time between warm-up and competition.

scholarly journals Palatable Flavoured Fluids without Carbohydrates and Electrolytes Do Not Enhance Voluntary Fluid Consumption in Male Collegiate Basketball Players in the Heat

Nutrients ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 4197
Author(s):  
Bernadette Cherianne Taim ◽  
Haresh T. Suppiah ◽  
Jericho Wee ◽  
Marcus Lee ◽  
Jason K. W. Lee ◽  
...  
Keyword(s):  
Perceived Exertion ◽  
Rest Period ◽  
Urine Specific Gravity ◽  
Plain Water ◽  
Fluid Consumption ◽  
Ratings Of Perceived Exertion ◽  
Basketball Players ◽  
Performance Deficits ◽  
Collegiate Basketball ◽  
And Performance

Using palatable fluids to enhance drinking in athletes who display insufficient compensatory hydration behaviour may mitigate the risks of hypohydration and performance deficits. However, it is unclear whether flavour can independently enhance fluid consumption. This study examined the effects of a colourless, artificially sweetened flavoured water (FW), without carbohydrates and with negligible amounts of sodium, compared to plain water (W) on fluid consumption in male collegiate basketball players in a practical game setting. Eighteen male basketball players (age 23.1 ± 1.3 years) played a 3v3 basketball small-sided game. The players were randomly assigned to consume either FW or W. Pre-game urine-specific gravity, fluid consumption, body mass, and hedonic taste perceptions were assessed. Basketball performance was analysed through notational analysis. Ratings of perceived exertion and thirst were recorded at pre-, post-game, and at each rest period. Heart rate was recorded throughout the gameplay. Despite significantly higher hedonic ratings for FW than W (6.78 ± 0.83 vs. 5.56 ± 1.33, p = 0.033, d = 1.36), there were no significant differences in fluid consumption (1083 ± 32 mL vs. 1421 ± 403 mL, p = 0.068, d = 0.92). Our result highlighted that using palatable fluids as a strategy to increase fluid consumption during high-intensity gameplay in the heat may not be effective if used without carbohydrates and electrolytes. Practitioners could consider both fluid palatability and composition in establishing a hydration plan for athletes.

Limiting the Rise in Core Temperature During a Rugby Sevens Warm-Up With an Ice Vest

2019 ◽  
Vol 14 (9) ◽  
pp. 1212-1218 ◽  
Author(s):  
Lee Taylor ◽  
Christopher J. Stevens ◽  
Heidi R. Thornton ◽  
Nick Poulos ◽  
Bryna C.R. Chrismas
Keyword(s):  
Core Temperature ◽  
Effect Size ◽  
Perceived Exertion ◽  
Thermal Sensation ◽  
Experimental Period ◽  
Rating Of Perceived Exertion ◽  
Warm Up ◽  
Wet Bulb Globe Temperature ◽  
Before And After ◽  
Globe Temperature

Purpose: To determine how a cooling vest worn during a warm-up could influence selected performance (countermovement jump [CMJ]), physical (global positioning system [GPS] metrics), and psychophysiological (body temperature and perceptual) variables. Methods: In a randomized, crossover design, 12 elite male World Rugby Sevens Series athletes completed an outdoor (wet bulb globe temperature 23–27°C) match-specific externally valid 30-min warm-up wearing a phase-change cooling vest (VEST) and without (CONTROL), on separate occasions 7 d apart. CMJ was assessed before and after the warm-up, with GPS indices and heart rate monitored during the warm-ups, while core temperature (Tc; ingestible telemetric pill; n = 6) was recorded throughout the experimental period. Measures of thermal sensation (TS) and thermal comfort (TC) was obtained pre-warm-up and post-warm-up, with rating of perceived exertion (RPE) taken post-warm-ups. Results: Athletes in VEST had a lower ΔTc (mean [SD]: VEST = 1.3°C [0.1°C]; CONTROL = 2.0°C [0.2°C]) from pre-warm-up to post-warm-up (effect size; ±90% confidence limit: −1.54; ±0.62) and Tc peak (mean [SD]: VEST = 37.8°C [0.3°C]; CONTROL = 38.5°C [0.3°C]) at the end of the warm-up (−1.59; ±0.64) compared with CONTROL. Athletes in VEST demonstrated a decrease in ΔTS (−1.59; ±0.72) and ΔTC (−1.63; ±0.73) pre-warm-up to post-warm-up, with a lower RPE post-warm-up (−1.01; ±0.46) than CONTROL. Changes in CMJ and GPS indices were trivial between conditions (effect size < 0.2). Conclusions: Wearing the vest prior to and during a warm-up can elicit favorable alterations in physiological (Tc) and perceptual (TS, TC, and RPE) warm-up responses, without compromising the utilized warm-up characteristics or physical-performance measures.

scholarly journals Influence of Knowledge of Task Endpoint on Pacing and Performance During Simulated Rugby League Match Play

2017 ◽  
Vol 12 (9) ◽  
pp. 1192-1198 ◽  
Author(s):  
Jamie Highton ◽  
Thomas Mullen ◽  
Craig Twist
Keyword(s):  
High Intensity ◽  
Perceived Exertion ◽  
Random Order ◽  
Exercise Duration ◽  
Rugby League ◽  
Rating Of Perceived Exertion ◽  
Match Play ◽  
And Performance ◽  
Rugby Players ◽  
Trial Participants

Purpose:To examine the influence of knowledge of exercise duration on pacing and performance during simulated rugby league match play. Methods:Thirteen male university rugby players completed 3 simulated rugby league matches (RLMSP-i) on separate days in a random order. In a control trial, participants were informed that they would be performing 2 × 23-min bouts (separated by 20 min) of the RLMSP-i (CON). In a second trial, participants were informed that they would be performing 1 × 23-min bout of the protocol but were then asked to perform another 23-min bout (DEC). In a third trial, participants were not informed of the exercise duration and performed 2 × 23-min bouts (UN). Results:Distance covered and high-intensity running were higher in CON (4813 ± 167 m, 26 ± 4.1 m/min) than DEC (4764 ± 112 m, 25.2 ± 2.8 m/min) and UN (4744 ± 131 m, 24.4 m/min). Compared with CON, high-intensity running and peak speed were typically higher for DEC in bout 1 and lower in bout 2 of the RLMSP-i, while UN was generally lower throughout. Similarly, DEC resulted in an increased heart rate, blood lactate, and rating of perceived exertion than CON in bout 1, whereas these variables were lower throughout the protocol in UN. Conclusions:Pacing and performance during simulated rugby league match play depend on an accurate understanding of the exercise endpoint. Applied practitioners should consider informing players of their likely exercise duration to maximize running.

scholarly journals A Mixed-Method Approach of Pre-Cooling Enhances High-Intensity Running Performance in the Heat

2021 ◽  
pp. 26-34
Author(s):  
Minxiao Xu ◽  
Zhaozhao Wu ◽  
Yanan Dong ◽  
Chaoyi Qu ◽  
Yaoduo Xu ◽  
...  
Keyword(s):  
High Intensity ◽  
Perceived Exertion ◽  
Thermal Sensation ◽  
Rating Of Perceived Exertion ◽  
Urine Specific Gravity ◽  
Sweat Loss ◽  
Experimental Conditions ◽  
Male Athletes ◽  
Hot Environment ◽  
Method Approach

We investigated whether single or combined methods of pre-cooling could affect high-intensity exercise performance in a hot environment. Seven male athletes were subjected to four experimental conditions for 30 min in a randomised order. The four experimental conditions were: 1) wearing a vest cooled to a temperature of 4 ℃ (Vest), 2) consuming a beverage cooled to a temperature of 4 ℃ (Beverage), 3) simultaneous usage of vest and consumption of beverage (Mix), and 4) the control trial without pre-cooling (CON). Following those experimental conditions, they exercised at a speed of 80% VO2max until exhaustion in the heat (38.1 ± 0.6 ℃, 55.3 ± 0.3% RH). Heart rate (HR), rectal temperature (Tcore), skin temperature (Tskin), sweat loss (SL), urine specific gravity (USG), levels of sodium (Na+) and potassium (K+), rating of perceived exertion (RPE), thermal sensation (TS), and levels of blood lactic acid ([Bla]) were monitored. Performance was improved using the mixed pre-cooling strategy (648.43 ± 77.53 s, p = 0.016) compared to CON (509.14 ± 54.57 s). Tcore after pre-cooling was not different (Mix: 37.01 ± 0.27 ℃, Vest: 37.19 ± 0.33 ℃, Beverage: 37.03 ± 0.35 ℃) in all cooling conditions compared to those of CON (37.31 ±0.29 ℃). A similar Tcore values was achieved at exhaustion in all trials (from 38.10 ℃ to 39.00 ℃). No difference in the level of USG was observed between the conditions. Our findings suggest that pre-cooling with a combination of cold vest usage and cold fluid intake can improve performance in the heat.

scholarly journals A Descriptive Analysis of Internal and External Loads for Elite-Level Tennis Drills

2014 ◽  
Vol 9 (5) ◽  
pp. 863-870 ◽  
Author(s):  
Alistair P. Murphy ◽  
Rob Duffield ◽  
Aaron Kellett ◽  
Machar Reid
Keyword(s):  
Perceived Exertion ◽  
Physiological Stress ◽  
Descriptive Analysis ◽  
Error Rates ◽  
Match Play ◽  
Monitoring Strategies ◽  
Junior Tennis ◽  
Elite Level ◽  
Training Quality ◽  
Mental Exertion

Purpose:Planning tennis sessions accentuating physical development requires an understanding of training load (TL). The aims were to describe the external and internal TL of drills and analyze relationships between ratings of perceived exertion (RPE), TL, and other measures.Methods:Fourteen elite-level junior tennis athletes completed 259 individual drills. Six coaches helped devise classifications for all drills: recovery/defensive, open pattern, accuracy, 2-on-1 open, 2-on-1 net play, closed technical, point play, and match play. Notational analysis on stroke and error rates was performed postsession. Drill RPE and mental exertion were collected postdrill, while heart rate (HR) was recorded continuously.Results:Recovery/defensive, open pattern, and point play were significantly greater than closed technical drills (P < .05) for RPE and mental exertion, as were accuracy drills and match play (P < .05). Recovery/defensive, open-pattern, accuracy, and 2-on-1 open drills had higher stroke rates than match play (P < .05). Error rates of closed technical drills were significantly higher than for open pattern, 2-on-1 drills, point play, and match play (P < .05). No HR differences were observed (P > .05) between categories. Substantial correlations existed for drill RPE and TL with mental exertion (r > .62) for several categories. TL was substantially correlated with total strokes (r > .65), while HR and stroke and error rates were in slight to moderate agreement with RPE and TL (r < .51).Conclusions:Recovery/defensive drills are highest in physiological stress, making them ideal for maximizing physicality. Recovery/defensive drills compromised training quality, eliciting high error rates. In contrast, 2-on-1 net-play drills provided the lowest error rates, potentially appropriate for error-amelioration practice. Open-pattern drills were characterized by significantly higher stroke rates, suggesting congruence with high-repetition practice. Finally, with strong relationships between physical and mental perception, mental exertion may complement currently used monitoring strategies (TL and RPE).

Caffeine Ingestion and Performance of a 1,500-Metre Swim

1995 ◽  
Vol 20 (2) ◽  
pp. 168-177 ◽  
Author(s):  
Brian Robert MacIntosh ◽  
Bridget Margarette Wright
Keyword(s):  
Blood Glucose ◽  
Perceived Exertion ◽  
Plasma Potassium ◽  
Electrolyte Balance ◽  
Lower Plasma ◽  
Double Blind ◽  
Caffeine Ingestion ◽  
Warm Up ◽  
Ergogenic Effects ◽  
And Performance

The purpose of this study was to evaluate the potential ergogenic benefit of caffeine in the performance of a 1,500-meter swim. Caffeine (6 mg∙kg−1) or placebo was administered 2-1/2 hrs prior to the swim trial in a double-blind crossover design. Caffeine resulted in a significantly lower perceived exertion for 100-m warm-up swims. Subjects swam significantly (p < 0.05) faster with caffeine (20:58.8 ± 0:36.4, mean ± SEM) than without (21:21.8 ± 0:38). Plasma potassium was significantly lower prior to the swim with caffeine, and blood glucose was higher after that swim. Caffeine provides an ergogenic benefit for a 1,500-meter swim, an event that is completed in less than 25 min. Lower plasma potassium concentration prior to exercise and higher blood glucose following the trial suggest that electrolyte balance and glucose availability may be important aspects of the ergogenic effects of caffeine. Key words: methylxanthines, endurance, exercise, potassium, fatigue, swimming

scholarly journals Acute Effects of Different Postactivation Potentiation Protocols on Traditional Rowing Performance

2020 ◽  
Vol 18 (1) ◽  
pp. 80
Author(s):  
Alfonso Penichet-Tomas ◽  
Jose M. Jimenez-Olmedo ◽  
Luis Serra Torregrosa ◽  
Basilio Pueo
Keyword(s):  
Effect Size ◽  
Muscle Power ◽  
Average Power ◽  
Postactivation Potentiation ◽  
Warm Up ◽  
Maximal Load ◽  
Rowing Performance ◽  
Load Intensity ◽  
And Performance ◽  
Student’S T

Postactivation potentiation (PAP) describes an initial muscular activation with a submaximal or maximal load intensity that produces acute improvements in muscle power and performance in subsequent explosive activities. The objective of this study was to compare the effect of different PAP protocols in rowing performance. A crossover design involving seven rowers was used, in which two different PAP protocols were applied: PAP of maximal conditioning contractions (PAP MCC) on a rowing ergometer to provide greater transferability and, thus, enhance the magnitude of PAP stimuli on subsequent rowing performance; and PAP of maximal strength contractions (PAP MSC) in half squat and bench pull exercises, similar to the main exercises in rowing strength training, to perform a 20 s “all-out” test simulating a competition start. Student’s t-test was used to compare means of the variables (p < 0.05). Effect size statistics were calculated using Cohen’s d. The PAP MCC protocol resulted in significant differences, with an extremely large effect size in average power output (p = 0.034, d = 0.98) in the first 3 (p = 0.019, d = 1.15) and first 5 (p = 0.036, d = 0.91) strokes. This group also reached a greater number of strokes (p = 0.049, d = 2.29) and strokes per minute (p = 0.046, d = 1.15). PAP with maximal conditioning contractions in rowing warm-up enhanced subsequent rowing sprint and is an advisable strategy to potentiate performance at the start of rowing competitions and sprint regattas.

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