scholarly journals Effects of Half-Time Cooling Using a Fan with Skin Wetting on Thermal Response During Intermittent Cycling Exercise in the Heat

2021 ◽  
Vol 05 (03) ◽  
pp. E91-E98
Author(s):  
Jumpei Osakabe ◽  
Masanobu Kajiki ◽  
Kiho Kondo ◽  
Takaaki Matsumoto ◽  
Yoshihisa Umemura
Keyword(s):  
Perceived Exertion ◽  
Thermal Sensation ◽  
Rating Of Perceived Exertion ◽  
Half Time ◽  
Physiological Strain ◽  
Cycling Exercise ◽  
Repeated Sprint ◽  
Significant Difference ◽  
Sprint Cycling ◽  
Experimental Trials

AbstractThe present study investigated the effects of half-time (HT) break cooling using a fan and damp sponge on physiological and perceptual responses during the 2nd half of a repeated-sprint exercise in a hot environment. Eight physically active men performed a familiarization trial and two experimental trials of a 2×30-min intermittent cycling exercise protocol with a 15-min HT break in hot conditions (35°C, 50% relative humidity). Two experimental trials were conducted in random order: skin wetting with a fan (FANwet) and no cooling (CON). During the 2nd half, a repeated-sprint cycling exercise was performed: i. e., 5 s of maximal pedaling (body weight×0.075 kp) every minute, separated by 25 s of unloaded pedaling (80 rpm) and 30 s of rest. Rectal temperature, skin temperature (chest, forearm, thigh, and calf), heart rate, physiological strain index, rating of perceived exertion, thermal sensation, and comfort were significantly improved in the FANwet condition (P<0.05). There was no significant difference in the repeated-sprint cycling exercise performance between conditions. The results suggest that skin wetting with a fan during the HT break is a practical and effective cooling strategy for mitigating physiological and perceptual strain during the 2nd half in hot conditions.

Heat Added to Repeated-Sprint Training in Hypoxia Does Not Affect Cycling Performance

2021 ◽  
pp. 1-9
Author(s):  
Myles C. Dennis ◽  
Paul S.R. Goods ◽  
Martyn J. Binnie ◽  
Olivier Girard ◽  
Karen E. Wallman ◽  
...  
Keyword(s):  
Oxygen Saturation ◽  
Core Temperature ◽  
Perceived Exertion ◽  
Thermal Sensation ◽  
Rating Of Perceived Exertion ◽  
Sprint Training ◽  
Active Recovery ◽  
Repeated Sprint ◽  
Air Temperatures ◽  
Desirable Outcome

Purpose: This study aimed to assess the influence of graded air temperatures during repeated-sprint training in hypoxia (RSH) on performance and physiological responses. Methods: Ten well-trained athletes completed one familiarization and 4 experimental sessions at a simulated altitude of 3000 m (0.144 FIO2) above sea level. Air temperatures utilized across the 4 experimental sessions were 20°C, 25°C, 30°C, and 35°C (all 50% relative humidity). The participants performed 3 sets of 5 × 10 seconds “all-out” cycle sprints, with 20 seconds of active recovery between sprints and 5 minutes of active recovery between sets (recovery intensity = 120 W). Core temperature, skin temperature, pulse oxygen saturation, heart rate, rating of perceived exertion, and thermal sensation were collected. Results: There were no differences between conditions for peak power, mean power, and total work in each set (P > .05). There were no condition × time interaction effects for any variables tested. The peak core temperature was highest at 30°C (38.06°C [0.31°C]). Overall, the pulse oxygen saturation was higher at 35°C than at 20°C (P < .001; d < 0.8), 25°C (P < .001; d = 1.12 ± 0.54, large), and 30°C (P < .001; d = 0.84 ± 0.53, large). Conclusion: Manipulating air temperature between 20°C and 35°C had no effect on performance or core temperature during a typical RSH session. However, the pulse oxygen saturation was preserved at 35°C, which may not be a desirable outcome for RSH interventions. The application of increased levels of ambient heat may require a different approach if augmenting the RSH stimulus is the desired outcome.

scholarly journals Repeated-bout exercise in the heat in young athletes: physiological strain and perceptual responses

2009 ◽  
Vol 106 (2) ◽  
pp. 476-485 ◽  
Author(s):  
Michael F. Bergeron ◽  
Melissa D. Laird ◽  
Elaina L. Marinik ◽  
Joel S. Brenner ◽  
Jennifer L. Waller
Keyword(s):  
Perceived Exertion ◽  
Intermittent Exercise ◽  
Thermal Sensation ◽  
Recovery Period ◽  
Exercise Bout ◽  
Rating Of Perceived Exertion ◽  
Strenuous Exercise ◽  
Age Group ◽  
Young Athletes ◽  
Physiological Strain

A short recovery period between same-day competitions is common practice in organized youth sports. We hypothesized that young athletes will experience an increase in physiological strain and perceptual discomfort during a second identical exercise bout in the heat, with 1 h (21°C) between bouts, even with ample hydration. Twenty-four athletes (6 boys and 6 girls: 12–13 yr old, 47.7 ± 8.3 kg; 6 boys and 6 girls: 16–17 yr old, 61.0 ± 8.6 kg) completed two 80-min intermittent exercise bouts (treadmill 60%, cycle 40% peak oxygen uptake) in the heat (33°C, 48.9 ± 6.1% relative humidity). Sweat loss during each bout was similar within each age group (12–13 yr old: bout 1, 943.6 ± 237.1 ml; bout 2, 955.5 ± 250.3 ml; 16–17 yr old: bout 1, 1,382.2 ± 480.7 ml; bout 2, 1,373.1 ± 472.2 ml). Area under the curve (AUC) was not statistically different ( P > 0.05) between bouts for core body temperature (12–13 yr old: bout 1 peak, 38.6 ± 0.4°C; bout 2, 38.4 ± 0.2°C; 16–17 yr old: bout 1 peak, 38.8 ± 0.7°C; bout 2, 38.7 ± 0.6°C), physiological strain index (12–13 yr old: bout 1 peak, 7.9 ± 0.9; bout 2, 7.5 ± 0.7; 16–17 yr old: bout 1 peak, 8.1 ± 1.5; bout 2, 7.9 ± 1.4), or thermal sensation for any age/sex subgroup or for all subjects combined. However, rating of perceived exertion AUC and peak were higher ( P = 0.0090 and 0.0004, respectively) during bout 2 in the older age group. Notably, four subjects experienced consistently higher responses throughout bout 2. With these healthy, fit, young athletes, 1 h of complete rest, cool down, and rehydration following 80 min of strenuous exercise in the heat was generally effective in eliminating any apparent carryover effects that would have resulted in greater thermal and cardiovascular strain during a subsequent identical exercise bout.

The Effect of Caffeine on Repeat-High-Intensity-Effort Performance in Rugby League Players

2017 ◽  
Vol 12 (2) ◽  
pp. 206-210 ◽  
Author(s):  
Brandon M. Wellington ◽  
Michael D. Leveritt ◽  
Vincent G. Kelly
Keyword(s):  
Blood Lactate ◽  
High Intensity ◽  
Perceived Exertion ◽  
Rugby League ◽  
Rating Of Perceived Exertion ◽  
Critical Periods ◽  
Placebo Condition ◽  
Double Blind ◽  
Significant Difference ◽  
Experimental Trials

Context:Repeat-high-intensity efforts (RHIEs) have recently been shown to occur at critical periods of rugby league matches.Purpose:To examine the effect that caffeine has on RHIE performance in rugby league players.Methods:Using a double-blind, placebo-controlled, crossover design, 11 semiprofessional rugby league players (age 19.0 ± 0.5 y, body mass 87.4 ± 12.9 kg, height 178.9 ± 2.6 cm) completed 2 experimental trials that involved completing an RHIE test after either caffeine (300 mg caffeine) or placebo (vitamin H) ingestion. Each trial consisted of 3 sets of 20-m sprints interspersed with bouts of tackling. During the RHIE test, 20-m-sprint time, heart rate (HR), rating of perceived exertion (RPE), and blood lactate were measured.Results:Total time to complete the nine 20-m sprints during the caffeine condition was 1.0% faster (28.46 ± 1.4 s) than during the placebo condition (28.77 ± 1.7 s) (ES = 0.18, 90%CI –0.7 to 0.1 s). This resulted in a very likely chance of caffeine being of benefit to RHIE performance (99% likely to be beneficial). These improvements were more pronounced in the early stages of the test, with a 1.3%, 1.0%, and 0.9% improvement in sprint performance during sets 1, 2, and 3 respectively. There was no significant difference in RPE across the 3 sets (P = .47, 0.48, 1.00) or mean HR (P = .36), maximal HR (P = .74), or blood lactate (P = .50) between treatment conditions.Conclusions:Preexercise ingestion of 300 mg caffeine produced practically meaningful improvements in RHIE performance in rugby league players.

scholarly journals Lactate, Heart Rate and Rating of Perceived Exertion Responses to Shorter and Longer Duration CrossFit® Training Sessions

2018 ◽  
Vol 3 (4) ◽  
pp. 60 ◽  
Author(s):  
Ramires Tibana ◽  
Nuno de Sousa ◽  
Jonato Prestes ◽  
Fabrício Voltarelli
Keyword(s):  
Heart Rate ◽  
Perceived Exertion ◽  
Recovery Period ◽  
Lactate Concentration ◽  
Blood Lactate Concentration ◽  
Cardiovascular Responses ◽  
Cardiovascular Fitness ◽  
Rating Of Perceived Exertion ◽  
Training Experience ◽  
Significant Difference

The aim of this study was to analyze blood lactate concentration (LAC), heart rate (HR), and rating perceived exertion (RPE) during and after shorter and longer duration CrossFit® sessions. Nine men (27.7 ± 3.2 years; 11.3 ± 4.6% body fat percentage and training experience: 41.1 ± 19.6 months) randomly performed two CrossFit® sessions (shorter: ~4 min and longer: 17 min) with a 7-day interval between them. The response of LAC and HR were measured pre, during, immediately after, and 10, 20, and 30 min after the sessions. RPE was measured pre and immediately after sessions. Lactate levels were higher during the recovery of the shorter session as compared with the longer session (shorter: 15.9 ± 2.2 mmol/L/min, longer: 12.6 ± 2.6 mmol/L/min; p = 0.019). There were no significant differences between protocols on HR during (shorter: 176 ± 6 bpm or 91 ± 4% HRmax, longer: 174 ± 3 bpm or 90 ± 3% HRmax, p = 0.387). The LAC was significantly higher throughout the recovery period for both training sessions as compared to pre-exercise. The RPE was increased immediately after both sessions as compared to pre-exercise, while there was no significant difference between them (shorter: 8.7 ± 0.9, longer: 9.6 ± 0.5; p = 0.360). These results demonstrated that both shorter and longer sessions induced elevated cardiovascular responses which met the recommendations for gains in cardiovascular fitness. In addition, both training sessions had a high metabolic and perceptual response, which may not be suitable if performed on consecutive days.

Training-Load Distribution in Endurance Runners: Objective Versus Subjective Assessment

2015 ◽  
Vol 10 (8) ◽  
pp. 1023-1028 ◽  
Author(s):  
Vincenzo Manzi ◽  
Antonio Bovenzi ◽  
Carlo Castagna ◽  
Paola Sinibaldi Salimei ◽  
Maurizio Volterrani ◽  
...  
Keyword(s):  
Heart Rate ◽  
Perceived Exertion ◽  
Training Load ◽  
Rating Of Perceived Exertion ◽  
Maximal Heart Rate ◽  
Long Distance ◽  
Running Speed ◽  
Training Time ◽  
Significant Difference ◽  
Training Methodologies

Purpose:To assess the distribution of exercise intensity in long-distance recreational athletes (LDRs) preparing for a marathon and to test the hypothesis that individual perception of effort could provide training responses similar to those provided by standardized training methodologies.Methods:Seven LDRs (age 36.5 ± 3.8 y) were followed during a 5-mo training period culminating with a city marathon. Heart rate at 2.0 and 4.0 mmol/L and maximal heart rate were used to establish 3 intensity training zones. Internal training load (TL) was assessed by training zones and TRIMPi methods. These were compared with the session-rating-of-perceived-exertion (RPE) method.Results:Total time spent in zone 1 was higher than in zones 2 and 3 (76.3% ± 6.4%, 17.3% ± 5.8%, and 6.3% ± 0.9%, respectively; P = .000 for both, ES = 0.98, ES = 0.99). TL quantified by session-RPE provided the same result. The comparison between session-RPE and training-zones-based methods showed no significant difference at the lowest intensity (P = .07, ES = 0.25). A significant correlation was observed between TL RPE and TL TRIMPi at both individual and group levels (r = .79, P < .001). There was a significant correlation between total time spent in zone 1 and the improvement at the running speed of 2 mmol/L (r = .88, P < .001). A negative correlation was found between running speed at 2 mmol/L and the time needed to complete the marathon (r = –.83, P < .001).Conclusions:These findings suggest that in recreational LDRs most of the training time is spent at low intensity and that this is associated with improved performances. Session-RPE is an easy-to-use training method that provides responses similar to those obtained with standardized training methodologies.

scholarly journals Determination of ventilatory threshold based on rating of perceived exertion scale

2004 ◽  
Vol 132 (11-12) ◽  
pp. 409-413 ◽  
Author(s):  
Stanimir Stojiljkovic ◽  
Dejan Nesic ◽  
Sanja Mazic ◽  
Dejana Popovic ◽  
Dusan Mitrovic ◽  
...  
Keyword(s):  
Perceived Exertion ◽  
Ventilatory Threshold ◽  
Rating Of Perceived Exertion ◽  
Physically Active ◽  
Mean Values ◽  
Significant Difference ◽  
Continuous Test ◽  
Dependent Samples ◽  
Increasing Load

The objective of the study was to test the possibility of using the fixed value (12-13) of the Rating of Perceived scale (RPE scale), as a valid method for determination of ventilatory threshold (VT). The sample of the subjects included 32 physically active males (age: 22.3; TV: 180.5; TM: 75.5 kg; V02max: 57.1 mL/kg/min). During the continuous test of progressively increasing load on a treadmill, cardiorespiratory and other parameters were monitored using ECG and gas analyzer. Following the test, VT and V02max were determined. During the test, at each level, at the scale from 6 to 20, the subjects pointed the number that suited best their currently feeling of strain. The RPE threshold was defined as constant value of 12-13. Average values of ventilatory and RPE threshold were expressed by parameters that were monitored and then compared by using t-test for dependent samples. No significant difference was found between mean values of VT and RPE threshold, when they were expressed by relevant parameters: speed, load, heart rate, absolute and relative oxygen consumption. Fixed value (12-13) of RPE scale may be used to detect the exercise intensity that corresponds to ventilatory threshold.

Monitoring Workload in Elite Female Basketball Players During the In-Season Phase: Weekly Fluctuations and Effect of Playing Time

2019 ◽  
Vol 14 (7) ◽  
pp. 941-948 ◽  
Author(s):  
Henrikas Paulauskas ◽  
Rasa Kreivyte ◽  
Aaron T. Scanlan ◽  
Alexandre Moreira ◽  
Laimonas Siupsinskas ◽  
...  
Keyword(s):  
Perceived Exertion ◽  
Linear Models ◽  
Training Session ◽  
Rating Of Perceived Exertion ◽  
Basketball Players ◽  
Significant Difference ◽  
Women's Basketball ◽  
Playing Time ◽  
And Training ◽  
Basketball Teams

Purpose:To assess the weekly fluctuations in workload and differences in workload according to playing time in elite female basketball players.Methods:A total of 29 female basketball players (mean [SD] age 21 [5] y, stature 181 [7] cm, body mass 71 [7] kg, playing experience 12 [5] y) belonging to the 7 women’s basketball teams competing in the first-division Lithuanian Women’s Basketball League were recruited. Individualized training loads (TLs) and game loads (GLs) were assessed using the session rating of perceived exertion after each training session and game during the entire in-season phase (24 wk). Percentage changes in total weekly TL (weekly TL + GL), weekly TL, weekly GL, chronic workload, acute:chronic workload ratio, training monotony, and training strain were calculated. Mixed linear models were used to assess differences for each dependent variable, with playing time (low vs high) used as fixed factor and subject, week, and team as random factors.Results:The highest changes in total weekly TL, weekly TL, and acute:chronic workload ratio were evident in week 13 (47%, 120%, and 49%, respectively). Chronic workload showed weekly changes ≤10%, whereas monotony and training strain registered highest fluctuations in weeks 17 (34%) and 15 (59%), respectively. A statistically significant difference in GL was evident between players completing low and high playing times (P = .026, moderate), whereas no significant differences (P > .05) were found for all other dependent variables.Conclusions:Coaches of elite women’s basketball teams should monitor weekly changes in workload during the in-season phase to identify weeks that may predispose players to unwanted spikes and adjust player workload according to playing time.

Effects of isolated or combined carbohydrate and caffeine supplementation between 2 daily training sessions on soccer performance

2015 ◽  
Vol 40 (5) ◽  
pp. 457-463 ◽  
Author(s):  
Victor Amorim Andrade-Souza ◽  
Romulo Bertuzzi ◽  
Gustavo Gomes de Araujo ◽  
David Bishop ◽  
Adriano Eduardo Lima-Silva
Keyword(s):  
Heart Rate ◽  
Perceived Exertion ◽  
Lactate Concentration ◽  
Training Session ◽  
Rating Of Perceived Exertion ◽  
Plasma Lactate ◽  
Repeated Sprint ◽  
Plasma Lactate Concentration ◽  
Main Effects ◽  
Previous Training

This study aimed to investigate whether isolated or combined carbohydrate (CHO) and caffeine (CAF) supplementation have beneficial effects on performance during soccer-related tests performed after a previous training session. Eleven male, amateur soccer players completed 4 trials in a randomized, double-blind, and crossover design. In the morning, participants performed the Loughborough Intermittent Shuttle Test (LIST). Then, participants ingested (i) 1.2 g·kg−1 body mass·h−1 CHO in a 20% CHO solution immediately after and 1, 2, and 3 h after the LIST; (ii) CAF (6 mg·kg−1 body mass) 3 h after the LIST; (iii) CHO combined with CAF (CHO+CAF); and (iv) placebo. All drinks were taste-matched and flavourless. After this 4-h recovery, participants performed a countermovement jump (CMJ) test, a Loughborough Soccer Passing Test (LSPT), and a repeated-sprint test. There were no main effects of supplementation for CMJ, LSPT total time, or best sprint and total sprint time from the repeated-sprint test (p > 0.05). There were also no main effects of supplementation for heart rate, plasma lactate concentration, rating of perceived exertion (RPE), pleasure–displeasure, and perceived activation (p > 0.05). However, there were significant time effects (p < 0.05), with heart rate, plasma lactate concentration, RPE, and perceived activation increasing with time, and pleasure–displeasure decreasing with time. In conclusion, isolated and/or combined CHO and CAF supplementation is not able to improve soccer-related performance tests when performed after a previous training session.

scholarly journals Practical Torso Cooling During Soccer-Specific Exercise in the Heat

2018 ◽  
Vol 53 (11) ◽  
pp. 1089-1097 ◽  
Author(s):  
Kirstie Parris ◽  
Christopher J. Tyler
Keyword(s):  
Perceived Exertion ◽  
Intermittent Exercise ◽  
Thermal Sensation ◽  
Sprint Performance ◽  
Rating Of Perceived Exertion ◽  
Sprint Speed ◽  
Minute Period ◽  
Improve Exercise Performance ◽  
C 50 ◽  
Cool Conditions

Context Precooling and midevent cooling of the torso using cooling vests can improve exercise performance in the heat with or without physiological changes; however, the effects of such cooling during intermittent exercise in the heat are unknown. Objective To investigate the effects of torso cooling during intermittent exercise in the heat (35°C, 50% relative humdity) on sprint performance and the physiological and perceptual responses to the exercise. Design Crossover study. Setting Walk-in environmental chamber. Patients or Other Participants Ten non–heat-acclimated, male soccer players (age = 25 ± 2 years, height = 1.77 ± 0.06 m, mass = 72.9 ± 7.6 kg). Intervention(s) Two 90-minute bouts of soccer-specific intermittent running in the heat: 1 trial with a cooling vest worn during the exercise and 1 trial without a cooling vest. Each trial comprised two 45-minute periods separated by approximately 15 minutes of seated rest in cool conditions (approximately 23°C, 50% relative humdity). Main Outcome Measure(s) Peak sprint speed, rectal temperature (Tr), mean-weighted skin temperature (Tsk), heart rate (HR), rating of perceived exertion (RPE), and thermal sensation (TS) were measured every 5 minutes. Results Peak sprint performance was largely unaffected by the cooling vest. The Tr, Tsk, HR, RPE, and TS were unaffected in the cooling-vest trial during the first 45 minutes, but Tr rose at a slower rate in the cooling-vest trial (0.026°C.min–1 ± 0.008°C.min–1) than in the no-vest trial (0.032°C.min–1 ± 0.009°C.min–1). During the second 45-minute period, Tr, Tr rate of rise, Tsk, RPE, and TS were lower in the cooling-vest trial (Hedges g range, 0.55–0.84), but mean HR was unaffected. Conclusions Wearing a cooling vest during soccer-specific intermittent running in the heat reduced physiological and perceptual strain but did not increase peak sprint speed.

A synthetic undergarment increases physiological strain

2019 ◽  
Vol 28 (4) ◽  
pp. 275 ◽  
Author(s):  
Matthew C. Dorton ◽  
Brent C. Ruby ◽  
Charles L. Dumke
Keyword(s):  
Blood Flow ◽  
Skin Blood Flow ◽  
Perceived Exertion ◽  
Sweat Rate ◽  
Rest Period ◽  
Time Trial ◽  
Rating Of Perceived Exertion ◽  
Physiological Strain ◽  
Physiological Factors ◽  
Increased Risk

Our aim was to examine the effect of a synthetic material undergarment on heat stress during exercise in a hot environment. Ten active males completed two trials of intermittent (50min walking, 10min sitting) treadmill walking over 3h in 35°C and 30% relative humidity. Subjects wore wildland firefighter flame-resistant meta-aramid blend pants and shirt with either a 100% cotton (C) or flame-retardant modacrylic undergarment (S), while carrying a 16-kg pack, helmet and leather gloves. Exercise was followed by a 30-min rest period without pack, helmet, gloves, and outerwear shirt. Rectal temperature and physiological strain were greater in S than C (P=0.04). No significant differences were found for heart rate, rating of perceived exertion, energy expenditure or skin temperature between C and S. Skin blood flow increased significantly in S following the second hour of exercise, resulting in a time×trial interaction (P=0.001). No significant differences for skin blood flow were found post exercise. Sweat rate and percent dehydration were not different between C and S. These data indicate that, of the two undergarments investigated, the synthetic undergarment negatively affected physiological factors that have been shown to indicate an increased risk of heat-related injuries.

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