Publications by authors named "Alexandre Guimard"

Article Synopsis
  • - The study investigates how taking melatonin at night influences cognitive and physical performance the next day, particularly in professional soccer players.
  • - Results showed that melatonin improved sleep quality and led to better performances in tests like handgrip strength, squat jump, and reaction time, alongside decreases in perceived exertion and fatigue.
  • - Despite these benefits, levels of blood lactate and glucose remained unchanged after melatonin ingestion, suggesting specific performance enhancements without affecting these metabolic markers.
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Although cold water immersion (CWI) is one of the most widely used post-exercise strategies to accelerate recovery processes, the benefits of CWI may be associated with placebo effects. This study aimed to compare the effects of CWI and placebo interventions on time course of recovery after the Loughborough Intermittent Shuttle Test (LIST). In a randomized, counterbalanced, crossover study, twelve semi-professional soccer players (age 21.

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Despite changes in the underwater sections of swimming races affecting overall performance, there is no information about the effects of the apnea-induced changes on the physiological state of competitive swimmers. The aim of the present research was to examine the effect of changes in the underwater race sections on the physiological [blood lactate concentration, heart rate, and rating of perceived exertion (RPE)] and biomechanical (underwater time, distance, and velocity) parameters of competitive swimmers. Twelve youth competitive swimmers belonging to the national team (706 ± 28.

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It is well known that the duration of apnea is longer in static than in dynamic conditions, but the impact of exercise intensity on the apnea duration needs to be investigated. The aim of this study was to determine the relationship between apnea duration and exercise intensity, and the associated metabolic parameters. Ten healthy active young non-apnea trained (NAT) men participated in this study.

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Although the role of underwater phases is well-known, no study has taken an interest in describing and quantifying the distance and time spent in apnea as a condition for optimal performance. This study aimed to investigate the impact of time and distance spent underwater and surface parameters on the swimming performance of elite swimmers. The performances of 79 swimmers in 100-m freestyle were analyzed (short-course).

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The aim was to assess the cardiac, arterial oxygen saturation, lactate, hormonal and Borg rating of perceived exertion (RPE) responses to acute apnea in relation to apnea capacity in 18 middle-aged triathletes. Subjects were monitored while swimming two 50-m freestyle exercise trials with fins at maximal speed: with normal frequency breathing (NB) and with complete apnea (Ap); the latter was used to assess apnea capacity. The subjects with significant alteration in swimming performance inducing a time increase greater than 2.

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Purpose: The aim of this study was to compare the muscle oxygenation between trained and untrained subjects during heavy exercise until exhaustion at two extreme pedaling cadences using a NIRS system.

Methods: Nine untrained male subjects and nine male competitive triathletes cycled until exhaustion at an intensity corresponding to 90 % of the power output achieved at peak oxygen uptake at 40 and 100 rpm. Gas exchanges were measured breath-by-breath during each exercise.

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Competitive swimmers regularly perform apnea series with or without fins as part of their training, but the ergogenic and metabolic repercussions of acute and chronic apnea have not been examined. Therefore, we aimed to investigate the cardiovascular, lactate, arterial oxygen saturation and hormonal responses to acute apnea in relation to performance in male swimmers. According to a randomized protocol, 15 national or regional competitive swimmers were monitored while performing four 100-m freestyle trials, each consisting of four 25-m segments with departure every 30 seconds at maximal speed in the following conditions: with normal frequency breathing with fins (F) and without fins (S) and with complete apnea for the four 25-m segments with (FAp) and without fins (SAp).

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