Several studies have reported that physical performances are affected by partial sleep deprivation (PSD). 1 – 6 PSD reduces aerobic intermittent, 1 , 2 time to exhaustion, 3 , 4 short-term all-out, 5 and repeated sprint 6 performances. Several studies have found that PSD caused by awakening at
Mohamed Romdhani, Nizar Souissi, Imen Moussa-Chamari, Yassine Chaabouni, Kacem Mahdouani, Zouheir Sahnoun, Tarak Driss, Karim Chamari, and Omar Hammouda
Chiara Gattoni, Michele Girardi, Barry Vincent O’Neill, and Samuele Maria Marcora
Sleep deprivation (SD) is very common during ultraendurance competitions, 1 and it is known to reduce endurance performance. 2 At present, naps 1 and caffeine 3 are the most common strategies used to reduce the negative effects of SD on ultraendurance performance. Here we propose and apply a
Mohamed Romdhani, Nizar Souissi, Yassine Chaabouni, Kacem Mahdouani, Tarak Driss, Karim Chamari, and Omar Hammouda
Despite sleep being acknowledged as an important factor for optimal athletic performance, poor sleep and/or partial sleep deprivation (PSD) are common prior to major competitions. 1 As reported in several studies, PSD deteriorates athletes’ short-term high-intensity exercise and cognitive
Melissa Skein, Rob Duffield, Geoffrey M. Minett, Alanna Snape, and Alistair Murphy
This study examined the effects of overnight sleep deprivation on recovery after competitive rugby league matches.
Eleven male amateur rugby league players played 2 competitive matches, followed by either a normal night’s sleep (~8 h; CONT) or a sleep-deprived night (~0 h; SDEP) in a randomized fashion. Testing was conducted the morning of the match, immediately postmatch, 2 h postmatch, and the next morning (16 h postmatch). Measures included countermovement-jump (CMJ) distance, knee-extensor maximal voluntary contraction (MVC) and voluntary activation (VA), venous-blood creatine kinase (CK) and C-reactive protein (CRP), perceived muscle soreness, and a word–color recognition cognitive-function test. Percent change between postmatch and 16-h postmatch was reported to determine the effect of the intervention the next morning.
Large effects indicated a greater postmatch to 16-h-postmatch percentage decline in CMJ distance after SDEP than in CONT (P = .10–.16, d = 0.95–1.05). Similarly, the percentage decline in incongruent word–color reaction times was increased in SDEP trials (P = .007, d = 1.75). Measures of MVC did not differ between conditions (P = .40–.75, d = 0.13–0.33), although trends for larger percentage decline in VA were detected in SDEP (P = .19, d = 0.84). Furthermore, large effects indicated higher CK and CRP responses 16 h postmatch in SDEP than in CONT (P = .11–.87, d = 0.80–0.88).
Sleep deprivation negatively affected recovery after a rugby league match, specifically impairing CMJ distance and cognitive function. Practitioners should promote adequate postmatch sleep patterns or adjust training demands the next day to accommodate the altered physical and cognitive state after sleep deprivation.
Grégoire P. Millet, Eric Hermand, and Rémy Hurdiel
No stop signs/Speed limit/Nobody’s gonna slow me down/Like a wheel/Gonna spin it//I’m on the highway to hell/Highway to hell. (AC/DC, 1979) We read with great interest the case study by Gattoni et al 1 on a novel and experimental intervention called sleep deprivation (SD) training, consisting of a
Christian Cook, C. Martyn Beaven, Liam P. Kilduff, and Scott Drawer
This study aimed to determine whether caffeine ingestion would increase the workload voluntarily chosen by athletes in a limited-sleep state.
In a double-blind, crossover study, 16 professional rugby players ingested either a placebo or 4 mg/kg caffeine 1 hr before exercise. Athletes classified themselves into nondeprived (8 hr+) or sleep-deprived states (6 hr or less). Exercise comprised 4 sets of bench press, squats, and bent rows at 85% 1-repetition maximum. Athletes were asked to perform as many repetitions on each set as possible without failure. Saliva was collected before administration of placebo or caffeine and again before and immediately after exercise and assayed for testosterone and cortisol.
Sleep deprivation produced a very large decrease in total load (p = 1.98 × 10−7). Caffeine ingestion in the nondeprived state resulted in a moderate increase in total load, with a larger effect in the sleep-deprived state, resulting in total load similar to those observed in the nondeprived placebo condition. Eight of the 16 athletes were identified as caffeine responders. Baseline testosterone was higher (p < .05) and cortisol trended lower in non-sleep-deprived athletes. Changes in hormones from predose to preexercise correlated to individual workload responses to caffeine. Testosterone response to exercise increased with caffeine compared with placebo, as did cortisol response.
Caffeine increased voluntary workload in professional athletes, even more so under conditions of self-reported limited sleep. Caffeine may prove worthwhile when athletes are tired, especially in those identified as responders.
Francis Degache, Jean-Benoît Morin, Lukas Oehen, Kenny Guex, Guido Giardini, Federico Schena, Guillaume Y. Millet, and Grégoire P. Millet
The aim of study was to examine the effects of the world’s most challenging mountain ultramarathon (Tor des Géants [TdG]) on running mechanics. Mechanical measurements were undertaken in male runners (n = 16) and a control group (n = 8) before (PRE), during (MID), and after (POST) the TdG. Contact (t c) and aerial (t a) times, step frequency (f), and running velocity (v) were sampled. Spring-mass parameters of peak vertical ground-reaction force (F max), vertical downward displacement of the center of mass (Δz), leg-length change (ΔL), and vertical (k vert) and leg (k leg) stiffness were computed. Significant decreases were observed in runners between PRE and MID for t a (P < .001), F max (P < .001), Δz (P < .05), and k leg (P < .01). In contrast, f significantly increased (P < .05) between PRE and MID-TdG. No further changes were observed at POST for any of those variables, with the exception of k leg, which went back to PRE. During the TdG, experienced runners modified their running pattern and spring-mass behavior mainly during the first half. The current results suggest that these mechanical changes aim at minimizing the pain occurring in lower limbs mainly during the eccentric phases. One cannot rule out that this switch to a “safer” technique may also aim to anticipate further damages.
Kazuto Omiya, Yoshihiro J Akashi, Kihei Yoneyama, Naohiko Osada, Kazuhiko Tanabe, and Fumihiko Miyake
The aim of this study was to clarify the mechanism of impaired exercise tolerance in chronic sleep-restricted conditions by investigating variables related to heart-rate (HR) response to sympathetic nervous stimulation. Sixteen healthy men (mean age 21.5 years) were tested in a control state, acute sleep-loss state, and chronic sleeprestricted state. Participants underwent cardiopulmonary exercise testing in each state. Their norepinephrine (NE) concentration was measured before and immediately after exercise. Intracellular magnesium (Mg) concentration was measured in a resting state. Exercise duration was shorter and the ratio of HR response to the percentage increase in NE was higher in the chronic sleep-restricted state than in the control state. Intracellular Mg gradually decreased from control to chronic sleep restriction. There was a negative correlation between peak exercise duration and the ratios of HR response to the rate of increase in NE. Intracellular Mg was positively correlated with the ratios of HR response to the increase in NE both in control and in acute sleep loss. The authors conclude that the impaired exercise tolerance in a chronic sleep-restricted state is caused by hypersensitivity of the HR response to sympathetic nervous stimulation, which showed a compensation for decreased intracellular Mg concentration.
Giovanna Ghiani, Sara Magnani, Azzurra Doneddu, Gianmarco Sainas, Virginia Pinna, Marco Caboi, Girolamo Palazzolo, Filippo Tocco, and Antonio Crisafulli
involve circumnavigation of the globe and can last more than 100 days. During Solo races, the sailor is exposed to many consecutive bouts of high-intensity physical activity ( Myers et al., 2008 ). The level of physiological stress depends on many factors, such as weather conditions, craft model, sleep
Lara A. Carlson, Kaylee M. Pobocik, Michael A. Lawrence, Daniel A. Brazeau, and Alexander J. Koch
Adequate sleep is an important element for both health and performance, especially among elite athletes. According to the National Sleep Foundation, there have been consistent findings of exercise improving total sleep time and quality of sleep. 1 Sleep deprivation alters cognition, pain, mood