Subjective thermal strain impairs endurance performance in a temperate environment

2019 ◽  
Vol 202 ◽  
pp. 36-44 ◽  
Author(s):  
Jeroen Van Cutsem ◽  
Bart Roelands ◽  
Kevin De Pauw ◽  
Romain Meeusen ◽  
Samuele Marcora
Keyword(s):  
Thermal Strain ◽  
Endurance Performance ◽  
Temperate Environment

scholarly journals Postexercise cooling interventions and the effects on exercise-induced heat stress in a temperate environment

2012 ◽  
Vol 37 (5) ◽  
pp. 965-975 ◽  
Author(s):  
Christophe Hausswirth ◽  
Rob Duffield ◽  
Hervé Pournot ◽  
François Bieuzen ◽  
Julien Louis ◽  
...  
Keyword(s):  
Oxygen Uptake ◽  
Passive Control ◽  
Minute Ventilation ◽  
Water Immersion ◽  
Thermal Strain ◽  
Exercise Bout ◽  
Endurance Cycling ◽  
Temperate Environment ◽  
Cooling Jacket ◽  
Exercise Induced

The aim of this study was to examine the effects of cool water immersion (20 °C; CWI) while wearing a cooling jacket (Cryovest;V) and a passive control (PAS) as recovery methods on physiological and thermoregulatory responses between 2 exercise bouts in temperate conditions. Nine well-trained male cyclists performed 2 successive bouts of 45 min of endurance cycling exercise in a temperate environment (20 °C) separated by 25 min of the respective recovery interventions. Capillary blood samples were obtained to measure lactate (La–), sodium (Na+), bicarbonate (HCO3–) concentrations and pH, whilst body mass loss (BML), core temperature (Tcore), skin temperature (Tskin), heart rate (HR), oxygen uptake , and minute ventilation were measured before (Pre), immediately after the first exercise bout (Ex1), the recovery (R), and after the second exercise bout (Ex2). V and CWI both resulted in a reduction of Tskin at R (–2.1 ± 0.01 °C and –11.6 ± 0.01 °C, respectively, p < 0.01). Despite no difference in final values post-Ex2 (p > 0.05), V attenuated the rise in HR, minute ventilation, and oxygen uptake from Ex1 to Ex2, while Tcore and Tskin were significantly lower following the second session (p < 0.05). Further, CWI was also beneficial in lowering Tcore, Tskin, and BML, while a rise in Na+ was observed following Ex2 (p < 0.05). Overall results indicate that cooling interventions (V and CWI) following exercise in a temperate environment provide a reduction in thermal strain during ensuing exercise bouts.

scholarly journals The effect of medium-term heat acclimation on endurance performance in a temperate environment.

2020 ◽  
pp. 1-25
Author(s):  
Jo Corbett ◽  
Heather C. Massey ◽  
Joseph T. Costello ◽  
Michael J. Tipton ◽  
Rebecca A. Neal
Keyword(s):  
Endurance Performance ◽  
Heat Acclimation ◽  
Medium Term ◽  
Temperate Environment

scholarly journals Caffeine Health Claims on Sports Supplement Labeling. Analytical Assessment According to EFSA Scientific Opinion and International Evidence and Criteria

Molecules ◽  
2021 ◽  
Vol 26 (7) ◽  
pp. 2095
Author(s):  
Pedro Estevan Navarro ◽  
Isabel Sospedra ◽  
Alejandro Perales ◽  
Cristina González-Díaz ◽  
Rubén Jiménez-Alfageme ◽  
...  
Keyword(s):  
Food Safety ◽  
Endurance Performance ◽  
Food Supplement ◽  
Cross Sectional Study ◽  
European Food Safety Authority ◽  
Health Claims ◽  
Cross Sectional ◽  
Strength Performance ◽  
Scientific Opinion ◽  
Term Performance

Caffeine is a food supplement widely consumed by athletes, but it has not been established. So far, the veracity of their labeling in terms of the dosage and cause/effect relationship aimed at the consumer. The aim is to analyze the health claims and the dosage presented on the labeling of caffeine supplements and to evaluate if they follow the European Food Safety Authority (EFSA) and international criteria. A descriptive cross-sectional study of a sample of caffeine supplements was carried out. The search was done through the Amazon and Google Shopping web portals. In order to assess the adequacy of the health claims, the guidelines of reference established by European Food Safety Authority were compared to the Academy of Nutrition and Dietetics, International Olympic Committee, and Australian Institute of Sport guidelines; in addition, recent systematic reviews were addressed. A review of labels of 42 caffeine supplements showed that, in less than 3% of the products were the health claims supported by the recommendations and by the labeled quantity of caffeine. The claims that fully complied the recommendations were, “improves or increases endurance performance”, “improves strength performance”, or “improves short-term performance”. In most cases, the recommended dosage was 200 mg/day for these products, which is the minimum for the caffeine effects to be declared. The rest of the health claims were not adequate or need to be modified. Most of the health claims identified indicated an unproven cause and effect, which constitutes consumer fraud, and so must be modified or eliminated.

Vector field path following of a full-wing solar-powered Unmanned Aerial Vehicle (UAV) landing based on Dubins path: a lesson from multiple landing failures

2021 ◽  
pp. 1-30
Author(s):  
A. Guo ◽  
Z. Zhou ◽  
R. Wang ◽  
X. Zhao ◽  
X. Zhu
Keyword(s):  
Vector Field ◽  
Path Following ◽  
Endurance Performance ◽  
Electrical Energy ◽  
Lateral Control ◽  
Special Configuration ◽  
Straight Line ◽  
Lateral Distance ◽  
Solar Powered ◽  
Line Path

Abstract The full-wing solar-powered UAV has a large aspect ratio, special configuration, and excellent aerodynamic performance. This UAV converts solar energy into electrical energy for level flight and storage to improve endurance performance. The UAV only uses a differential throttle for lateral control, and the insufficient control capability during crosswind landing results in a large lateral distance bias and leads to multiple landing failures. This paper analyzes 11 landing failures and finds that a large lateral distance bias at the beginning of the approach and the coupling of base and differential throttle control is the main reason for multiple landing failures. To improve the landing performance, a heading angle-based vector field (VF) method is applied to the straight-line and orbit paths following and two novel 3D Dubins landing paths are proposed to reduce the initial lateral control bias. The results show that the straight-line path simulation exhibits similar phenomenon with the practical failure; the single helical path has the highest lateral control accuracy; the left-arc to left-arc (L-L) path avoids the saturation of the differential throttle; and both paths effectively improve the probability of successful landing.

scholarly journals Monitoring Training and Recovery during a Period of Increased Intensity or Volume in Recreational Endurance Athletes

2021 ◽  
Vol 18 (5) ◽  
pp. 2401
Author(s):  
Olli-Pekka Nuuttila ◽  
Ari Nummela ◽  
Keijo Häkkinen ◽  
Santtu Seipäjärvi ◽  
Heikki Kyröläinen
Keyword(s):  
Heart Rate ◽  
Control Period ◽  
Endurance Performance ◽  
Training Period ◽  
Training Intensity ◽  
Countermovement Jump ◽  
Maximal Speed ◽  
Individualized Approach ◽  
Monitoring Training

The purpose of the study was to examine the effects of progressively increased training intensity or volume on the nocturnal heart rate (HR) and heart rate variability (HRV), countermovement jump, perceived recovery, and heart rate-running speed index (HR-RS index). Another aim was to analyze how observed patterns during the training period in these monitoring variables were associated with the changes in endurance performance. Thirty recreationally trained participants performed a 10-week control period of regular training and a 10-week training period of either increased training intensity (INT, n = 13) or volume (VOL, n = 17). Changes in endurance performance were assessed by an incremental treadmill test. Both groups improved their maximal speed on the treadmill (INT 3.4 ± 3.2%, p < 0.001; VOL 2.1 ± 1.8%, p = 0.006). In the monitoring variables, only between-group difference (p = 0.013) was found in nocturnal HR, which decreased in INT (p = 0.016). In addition, perceived recovery decreased in VOL (p = 0.021) and tended to decrease in INT (p = 0.056). When all participants were divided into low-responders and responders in maximal running performance, the increase in the HR-RS index at the end of the training period was greater in responders (p = 0.005). In conclusion, current training periods of increased intensity or volume improved endurance performance to a similar extent. Countermovement jump and HRV remained unaffected, despite a slight decrease in perceived recovery. Long-term monitoring of the HR-RS index may help to predict positive adaptations, while interpretation of other recovery-related markers may need a more individualized approach.

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