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.

Compression Garments: No Enhancement of High-Intensity Exercise in Hot Radiant Conditions

2013 ◽  
Vol 8 (5) ◽  
pp. 527-535 ◽  
Author(s):  
Martin J. Barwood ◽  
Jo Corbett ◽  
John Feeney ◽  
Paul Hannaford ◽  
Dan Henderson ◽  
...  
Keyword(s):  
Heat Load ◽  
Completion Time ◽  
Perceived Exertion ◽  
Thermal Sensation ◽  
Time Trial ◽  
Radiant Heat ◽  
Rating Of Perceived Exertion ◽  
Compression Garment ◽  
Mean Body Temperature ◽  
Hot Environment

Purpose:To establish the thermal and performance effects of wearing a lower-body graduated compression garment (GCG) in a hot environment (35.2°C ± 0.1°C) with a representative radiant heat load (~800 W/m2) in contrast to a control (running shorts) and sham condition (a compression garment 1 size larger than that recommended by the manufacturer), with the latter included to establish any placebo effect.Method:Eight participants (mean ± SD; age 21 ± 2 y, height 1.77 ± 0.06 m, mass 72.8 ± 7.1 kg, surface area, 1.89 ± 0.10 m2) completed 3 treadmill tests at a fixed speed for 15 min followed by a self-paced 5-km time trial. Performance (completion time) and pacing (split time), thermal responses (aural, skin, and mean body temperature, cardiac frequency), and perceptual responses (rating of perceived exertion [RPE], thermal sensation, thermal comfort) were measured.Results:Performance in the compression group was not different than in either sham or control at any stage (P > .05); completion time 26.08 ± 4.08, 26.05 ± 3.27, and 25.18 ± 3.15 min, respectively. At the end of the 5-km time trial, RPE was not different; it was 19 ± 1 across conditions. In general, thermal and perceptual responses were not different, although the radiant heat load increased site-specific skin temperature (quadriceps) in the garment conditions.Conclusion:GCG did not enhance performance in a hot environment with a representative radiant heat load. The sham treatment did not benefit perception. GCG provided no evidence of performance enhancement.

scholarly journals Cooling the Neck Region During Exercise in the Heat

2011 ◽  
Vol 46 (1) ◽  
pp. 61-68 ◽  
Author(s):  
Christopher James Tyler ◽  
Caroline Sunderland
Keyword(s):  
Skin Temperature ◽  
Perceived Exertion ◽  
Thermal Sensation ◽  
Thermal Strain ◽  
Neck Region ◽  
Rating Of Perceived Exertion ◽  
Hot Environment ◽  
Feeling Scale ◽  
Volitional Exhaustion ◽  
Test Variability

Abstract Context: Cooling the neck region can improve the ability to exercise in a hot environment. It might improve performance by dampening the perceived level of thermal strain, allowing individuals to override inhibitory signals. Objective: To investigate whether the enhanced ability to exercise in a hot environment observed when cooling the neck region occurs because of dampening the perceived level of thermal strain experienced and the subsequent overriding of inhibitory signals. Design: Crossover study. Setting: Walk-in environmental chamber. Patients or Other Participants: Eight endurance-trained, nonacclimated men (age  =  26 ± 2 years, height  =  1.79 ± 0.04 m, mass  =  77.0 ± 6.2 kg, maximal oxygen uptake [V˙O2max]  =  56.2 ± 9.2 mL·kg−1·min−1) participated. Intervention(s): Participants completed 4 running tests at approximately 70% V˙O2max to volitional exhaustion: 2 familiarization trials followed by 2 experimental trials (cooling collar [CC] and no collar [NC]). Trials were separated by 7 days. Familiarization and NC trials were performed without a collar and used to assess the test variability. Main Outcome Measure(s): Time to volitional exhaustion, heart rate, rectal temperature, neck skin temperature, rating of perceived exertion, thermal sensation, and feeling scale (pleasure/displeasure) were measured. Results: Time to volitional exhaustion was increased by 13.5% ± 3.8% (CC  =  43.15 ± 12.82 minutes, NC  =  38.20 ± 11.70 minutes; t7  =  9.923, P < .001) with the CC, which reduced mean neck skin temperature throughout the test (P < .001). Participants terminated exercise at identical levels of perceived exertion, thermal sensation, and feeling scale, but the CC enabled participants to tolerate higher rectal temperatures (CC  =  39.61°C ± 0.45°C, NC  =  39.18°C ± 0.7°C; t7  =  −3.217, P  =  .02) and heart rates (CC  =  181 ± 6 beats/min, NC  =  178 ± 9 beats/min; t7  =  −2.664, P  =  .03) at the point of termination. Conclusions: Cooling the neck increased the time taken to reach volitional exhaustion by dampening the perceived levels of thermal strain.

Making the Grade: An Exploration of Incline Running on a Bodyweight-Supportive Treadmill

2020 ◽  
pp. 1-5
Author(s):  
Megan Wagner ◽  
Kevin D. Dames
Keyword(s):  
Heart Rate ◽  
Oxygen Consumption ◽  
Repeated Measures ◽  
Perceived Exertion ◽  
Rating Of Perceived Exertion ◽  
Treadmill Running ◽  
Metabolic Effects ◽  
Metabolic Demand ◽  
Experimental Conditions ◽  
Cross Sectional

Context: Bodyweight-supporting treadmills are popular rehabilitation tools for athletes recovering from impact-related injuries because they reduce ground reaction forces during running. However, the overall metabolic demand of a given running speed is also reduced, meaning athletes who return to competition after using such a device in rehabilitation may not be as fit as they had been prior to their injury. Objective: To explore the metabolic effects of adding incline during bodyweight-supported treadmill running. Design: Cross-sectional. Setting: Research laboratory. Participants: Fourteen apparently healthy, recreational runners (6 females and 8 males; 21 [3] y, 1.71 [0.08] m, 63.11 [6.86] kg). Interventions: The participants performed steady-state running trials on a bodyweight-supporting treadmill at 8.5 mph. The control condition was no incline and no bodyweight support. All experimental conditions were at 30% bodyweight support. The participants began the sequence of experimental conditions at 0% incline; this increased to 1%, and from there on, 2% incline increases were introduced until a 15% grade was reached. Repeated-measures analysis of variance was used to compare all bodyweight-support conditions against the control condition. Main Outcome Measures: Oxygen consumption, heart rate, and rating of perceived exertion. Results: Level running with 30% bodyweight support reduced oxygen consumption by 21.6% (P < .001) and heart rate by 12.0% (P < .001) compared with the control. Each 2% increase in incline with bodyweight support increased oxygen consumption by 6.4% and heart rate by 3.2% on average. A 7% incline elicited similar physiological measures as the unsupported, level condition. However, the perceived intensity of this incline with bodyweight support was greater than the unsupported condition (P < .001). Conclusions: Athletes can maintain training intensity while running on a bodyweight-supporting treadmill by introducing incline. Rehabilitation programs should rely on quantitative rather than qualitative data to drive exercise prescription in this modality.

The Effect of Self-Paced and Prescribed Interset Rest Strategies on Performance in Strength Training

2019 ◽  
Vol 14 (7) ◽  
pp. 980-986
Author(s):  
Peter Ibbott ◽  
Nick Ball ◽  
Marijke Welvaert ◽  
Kevin G. Thompson
Keyword(s):  
Strength Training ◽  
Perceived Exertion ◽  
Mechanical Performance ◽  
Rest Period ◽  
Rating Of Perceived Exertion ◽  
Subjective Rating ◽  
Male Athletes ◽  
Rest Periods ◽  
Pacing Strategies ◽  
Feasible Alternative

Purpose: To assess pacing strategies using prescribed and self-selected interset rest periods and their influence on performance in strength-trained athletes. Methods: A total of 16 strength-trained male athletes completed 3 randomized heavy strength-training sessions (5 sets and 5 repetitions) with different interset rest periods. The interset rest periods were 3 min (3MIN), 5 min (5MIN), and self-selected (SS). Mechanical (power, velocity, work, and displacement), surface electromyography (sEMG), and subjective (rating of perceived exertion) and readiness-to-lift data were recorded for each set. Results: SS-condition interset rest periods increased from sets 1 to 4 (from 207.52 to 277.71 s; P = .01). No differences in mechanical performance were shown between the different interset rest-period conditions. Power output (210 W; 8.03%) and velocity (0.03 m·s−1; 6.73%) decreased as sets progressed for all conditions (P < .001) from set 1 to set 5. No differences in sEMG activity between conditions were shown; however, vastus medialis sEMG decreased as the sets progressed for each condition (1.75%; P = .005). All conditions showed increases in rating of perceived exertion as sets progressed (set 1 = 6.1, set 5 = 7.9; P < .001). Participants reported greater readiness to lift in the 5MIN condition (7.81) than in the 3MIN (7.09) and SS (7.20) conditions (P < .001). Conclusions: Self-selecting interset rest periods does not significantly change performance compared with 3MIN and 5MIN conditions. Given the opportunity, athletes will vary their interset rest periods to complete multiple sets of heavy strength training. Self-selection of interset rest periods may be a feasible alternative to prescribed interset rest periods.

Rating of perceived exertion during high-intensity treadmill running

2001 ◽  
Vol 33 (11) ◽  
pp. 1953-1958 ◽  
Author(s):  
MIKE DOHERTY ◽  
PAUL M. SMITH ◽  
MICHAEL G. HUGHES ◽  
DAVID COLLINS
Keyword(s):  
High Intensity ◽  
Perceived Exertion ◽  
Rating Of Perceived Exertion ◽  
Treadmill Running

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.

Hormonal, Physiological, and Physical Performance During Simulated Kickboxing Combat: Differences Between Winners and Losers

2016 ◽  
Vol 11 (4) ◽  
pp. 425-431 ◽  
Author(s):  
Ibrahim Ouergui ◽  
Philip Davis ◽  
Nizar Houcine ◽  
Hamza Marzouki ◽  
Monia Zaouali ◽  
...  
Keyword(s):  
Test Performance ◽  
High Intensity ◽  
Perceived Exertion ◽  
National Level ◽  
Wingate Test ◽  
Rating Of Perceived Exertion ◽  
Upper Body ◽  
Before And After ◽  
Mental Abilities ◽  
Physical Responses

The aim of the current study was to investigate the hormonal, physiological, and physical responses of simulated kickboxing competition and evaluate if there was a difference between winners and losers. Twenty athletes of regional and national level participated in the study (mean ± SD age 21.3 ± 2.7 y, height 170.0 ± 5.0 cm). Hormone (cortisol, testosterone, growth hormone), blood lactate [La], and glucose concentrations, as well as upper-body Wingate test and countermovement-jump (CMJ) performances, were measured before and after combats. Heart rate (HR) was measured throughout rounds 1, 2, and 3 and rating of perceived exertion (RPE) was taken after each round. All combats were recorded and analyzed to determine the length of different activity phases (high-intensity, low-intensity, and referee pause) and the frequency of techniques. Hormones, glucose, [La], HR, and RPE increased (all P < .001) precombat to postcombat, while a decrease was observed for CMJ, Wingate test performance, body mass (all P < .001), and time of high-intensity activities (P = .005). There was no difference between winners and losers for hormonal, physiological, and physical variables (P > .05). However, winners executed more jab cross, total punches, roundhouse kicks, total kicks, and total attacking techniques (all P < .042) than losers. Kickboxing is an intermittent physically demanding sport that induces changes in the stress-related hormones soliciting the anaerobic lactic system. Training should be oriented to enhance kickboxers’ anaerobic lactic fitness and their ability to strike at a sufficient rate. Further investigation is needed to identify possible differences in tactical and mental abilities that offer some insight into what makes winners winners.

Effects of Bout Duration on Players’ Internal and External Loads During Small-Sided Games in Young Soccer Players

2017 ◽  
Vol 12 (10) ◽  
pp. 1370-1377 ◽  
Author(s):  
Yusuf Köklü ◽  
Utku Alemdaroğlu ◽  
Hamit Cihan ◽  
Del P. Wong
Keyword(s):  
Heart Rate ◽  
High Intensity ◽  
Perceived Exertion ◽  
Young Male ◽  
Rating Of Perceived Exertion ◽  
Soccer Players ◽  
Moderate Intensity ◽  
Low Intensity ◽  
Playing Time ◽  
External Loads

Purpose: To investigate the effects of different bout durations on internal and external loads of young soccer players during different small-sided games (SSGs). Methods: Fifteen young male soccer players (average age 17 ± 1 y) participated in 2 vs 2, 3 vs 3, and 4 vs 4 SSGs. All games lasted 12 min playing time in total, but each SSG format further consisted of 4 bout durations: continuous (CON: 1 bout × 12 min) or interval with short (SBD: 6 bouts  × 2 min), medium (MBD: 3 bouts × 4 min), or long (LBD: 2 bouts × 6 min) bout durations. During the SSGs, heart-rate (HR) responses and distance covered in different speed zones (walking and low-intensity, moderate-intensity, and high-intensity running) were measured. Rating of perceived exertion (RPE) and blood lactate (La−) were determined at the end of each SSG. Results: The SBD format elicited significantly lower %HRmax responses compared to LBD and CON in all formats (P < .05). The SBD format also showed significantly shorter distances covered in walking and greater distances covered in moderate-intensity running, as well as significantly greater total distance covered compared to LBD and CON in all formats (P < .05). In addition, LBD produced significantly lower La− and RPE responses than SBD and CON in all formats (P < .05). Conclusions: These results suggest that coaches and sport scientists who want to achieve higher internal loads could use SBD and CON timing protocols, while those who want to achieve higher external loads might prefer to use SBD and MBD when planning all SSG formats.

scholarly journals The Quantification of Within-Week Session Intensity, Duration, and Intensity Distribution Across a Season in Australian Football Using the Session Rating of Perceived Exertion Method

2018 ◽  
Vol 13 (7) ◽  
pp. 940-946 ◽  
Author(s):  
Farhan Juhari ◽  
Dean Ritchie ◽  
Fergus O’Connor ◽  
Nathan Pitchford ◽  
Matthew Weston ◽  
...  
Keyword(s):  
Intensity Distribution ◽  
Mixed Models ◽  
High Intensity ◽  
Perceived Exertion ◽  
Linear Mixed Models ◽  
Training Session ◽  
Rating Of Perceived Exertion ◽  
Moderate Intensity ◽  
Low Intensity ◽  
Australian Football

Context: Team-sport training requires the daily manipulation of intensity, duration, and frequency, with preseason training focusing on meeting the demands of in-season competition and training on maintaining fitness. Purpose: To provide information about daily training in Australian football (AF), this study aimed to quantify session intensity, duration, and intensity distribution across different stages of an entire season. Methods: Intensity (session ratings of perceived exertion; CR-10 scale) and duration were collected from 45 professional male AF players for every training session and game. Each session’s rating of perceived exertion was categorized into a corresponding intensity zone, low (<4.0 arbitrary units), moderate (≥4.0 and <7.0), and high (≥7.0), to categorize session intensity. Linear mixed models were constructed to estimate session duration, intensity, and distribution between the 3 preseason and 4 in-season periods. Effects were assessed using linear mixed models and magnitude-based inferences. Results: The distribution of the mean session intensity across the season was 29% low intensity, 57% moderate intensity, and 14% high intensity. While 96% of games were high intensity, 44% and 49% of skills training sessions were low intensity and moderate intensity, respectively. Running had the highest proportion of high-intensity training sessions (27%). Preseason displayed higher training-session intensity (effect size [ES] = 0.29–0.91) and duration (ES = 0.33–1.44), while in-season game intensity (ES = 0.31–0.51) and duration (ES = 0.51–0.82) were higher. Conclusions: By using a cost-effective monitoring tool, this study provides information about the intensity, duration, and intensity distribution of all training types across different phases of a season, thus allowing a greater understanding of the training and competition demands of Australian footballers.

Effect of Low- and High-Glycemic-Index Meals on Metabolism and Performance During High-Intensity, Intermittent Exercise

2010 ◽  
Vol 20 (6) ◽  
pp. 447-456 ◽  
Author(s):  
Jonathan P. Little ◽  
Philip D. Chilibeck ◽  
Dawn Ciona ◽  
Scott Forbes ◽  
Huw Rees ◽  
...  
Keyword(s):  
Glycemic Index ◽  
Muscle Glycogen ◽  
High Intensity ◽  
Perceived Exertion ◽  
Intermittent Exercise ◽  
Random Order ◽  
Rating Of Perceived Exertion ◽  
Repeated Sprint ◽  
High Glycemic Index ◽  
And Performance

Consuming carbohydrate-rich meals before continuous endurance exercise improves performance, yet few studies have evaluated the ideal preexercise meal for high-intensity intermittent exercise, which is characteristic of many team sports. The authors’ purpose was to investigate the effects of low- and high-glycemic-index (GI) meals on metabolism and performance during high-intensity, intermittent exercise. Sixteen male participants completed three 90-min high-intensity intermittent running trials in a single-blinded random order, separated by ~7 d, while fasted (control) and 2 hr after ingesting an isoenergetic low-GI (lentil), or high-GI (potato and egg white) preexercise meal. Serum free fatty acids were higher and insulin lower throughout exercise in the fasted condition (p < .05), but there were no differences in blood glucose during exercise between conditions. Distance covered on a repeated-sprint test at the end of exercise was significantly greater in the low-GI and high-GI conditions than in the control (p < .05). Rating of perceived exertion was lower in the low-GI condition than in the control (p = .01). In a subsample of 5 participants, muscle glycogen availability was greater in the low- and high-GI conditions versus fasted control before the repeated-sprint test (p < .05), with no differences between low and high GI. When exogenous carbohydrates are not provided during exercise both low- and high-GI preexercise meals improve high-intensity, intermittent exercise performance, probably by increasing the availability of muscle glycogen. However, the GI does not influence markers of substrate oxidation during high-intensity, intermittent exercise.

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