Nap improved game-related technical performance and physiological response during small-sided basketball game in professional players.

The effect of 40-min nap (NAP) opportunity on psycho-physiological outcomes and technical performance during small-sided basketball game (SSG) was examined in ten professional basketball players. Nocturnal sleep and naps were monitored by actigraphic recording and sleep diaries. Nocturnal total sleep time (TST), time in bed (TIB), sleep efficiency (SE), sleep onset latency (SOL) and wake after sleep onset (WASO) were analyzed. Subjective sleep quality was assessed with visual analogue scale (VAS). Profile of mood state (POMS) and simple reaction time (SRT) were measured before and after Nap and no-nap (CON) conditions. During both test sessions, participants played 10-min SSG. Technical and tactical performances were assessed using Team Sport Assessment Procedure. Volume of play (VP), attack with ball (AB), efficiency index (EI) and performance score (PS) were determined. Heart rate (HR) was measured during SSG, and rating of perceive excretion (RPE) after. Lower HR (p ≤ 0.03, d ≥ 0.78) and RPE (p = 0.007, d = 1.11) were obtained in NAP compared to CON. There was no significant difference in TIB, TST, SE, WASO and VAS between CON and NAP conditions. AB, EI and PS were higher in NAP compared to CON (0.0002 ≤ p ≤ 0.001, 1.3 ≤ d ≤ 1.8). A significant reduction was observed in POMS' fatigue (p = 0.005, d = -1.16, Δ = -53.6%), anxiety (p = 0.02, d = -0.9, Δ = -32.1%), anger (p = 0.01, d = -0.94, Δ = -30.3%), and an improvement in vigor (p = 0.01, d = 0.99, Δ = + 23.8%); which may reflect better readiness after nap and more concentration to start a game-situation. In summary, NAP reduced fatigue, anger, anxiety and enhanced vigor, allowing better technical and tactical performances during basketball SSG.

Repeated low-dose caffeine ingestion during a night of total sleep deprivation improves endurance performance and cognitive function in young recreational runners: A randomized, double-blind, placebo-controlled study.

The present study aimed to assess the effects of repeated administration of low-dose caffeine during a night of total sleep deprivation on physical and cognitive performance. Twelve recreational runners (being non-habitual caffeine users) performed four test sessions in a double-blind randomized order after (i) a placebo or 6 mg/kg of caffeine ingestion during a baseline night (BN) or (ii) a placebo or three doses of 2 mg/kg of caffeine during a night of total sleep deprivation (TSD). At each session, they completed an exhaustive run at 75% of the final velocity in a Vameval test (Vvameval) around a 400 m outdoor athletics track and performed the correct detection and reaction time tasks. In comparison with BN, the TSD condition significantly impaired running performance, reaction time, and correct detections. On the contrary, caffeine intake improved exhaustive running performance after BN by 5.2% (p < .001) and after TSD by 8.9% (p < .001), increased correct detections after BN (p < .05) and TSD (p < .05), and decreased reaction time after BN (p < .01) and TSD (p < .05) compared to placebo. Therefore, the repeated ingestion of low-dose caffeine is an effective strategy to counteract the detrimental effects of total sleep deprivation on physical and cognitive performance.

Higher evening metabolic responses contribute to diurnal variation of self-paced cycling performance.

This study examined the effect of time of day (TOD) on physical performance, and physiological and perceptual responses to a 10-km cycling time trial (TT10km). Twelve physically trained subjects (20.3 ± 1.2 years, 74.3 ± 7.4 kg, 179.7 ± 5.5 cm) completed, in a randomized order, a TT10km in the morning and in the evening. Intra-aural temperature (IAT) was measured at rest and following the TT10km. Completion time, power output (PO), rating of perceived exertion (RPE), heart rate (HR), minute ventilation (V̇E), oxygen uptake (V̇O2), carbon dioxide production (V̇CO2) and respiratory exchange ratio (RER) were assessed every km during the TT10km. Blood lactate concentration [La] and blood glucose concentration [Glu] were assessed before, during and immediately after the TT10km. Faster completion time (Δ = 15.0s, p = 0.03) and higher IAT (Δ = 0.33°C, p = 0.02 for pre-TT10km) were obtained in the evening compared to the morning with a significant correlation between Δ completion time and Δ IAT at post-TT10 km (r = -0.83, p = 0.04). V̇O2, [La] and [Glu] increased significantly during both test sessions (p < 0.001) with higher values in the evening compared to the morning (p = 0.015, p = 0.04, p = 0.01, respectively). However, the remaining parameters were found to be only affected by the TT10km (p < 0.001). The TT10km generates a higher V̇O2 and higher [La] and [Glu] responses, contributing to a better cycling performance in the evening compared to the morning. The similar magnitude of the TOD effect on completion time and IAT at post-TT10km confirms that core temperature is one of the underlying factors contributing to the diurnal variation in physical performance.

Acute caffeine ingestion improves 3-km run performance, cognitive function, and psychological state of young recreational runners.

The current study aimed to assess the effects of caffeine administration on performance time, cognition, psychomotor state, and blood levels of oxidative stress markers following a 3-km run competition. Thirteen recreational runners performed two test sessions in a double-blind randomized order after placebo or 3 mg/kg of body mass of caffeine. At each session, subjects completed a 3-km running competition around a 400 m outdoor athletics track. Cognitive tasks (attention and reaction time), psychological tests (Feeling scale and Hooper), and blood collection were carried out before and after the run. In comparison with placebo, caffeine ingestion enhanced the 3-km performance time by 1.1% (p < 0.001) (10.13 ± 0.69 min versus 10.25 ± 0.72 min), improved attention by 15.6% (p < 0.001) and reaction-time by 5.9% (p < 0.05), increased good-feeling by 15.7% (p < 0.01), and lowered stress-feeling by 17.6% (p < 0.01) and pain-sensation by 11.3% (p < 0.05). However, no significant effects of caffeine were observed on oxidative stress markers. Only exercise resulted in increased levels of glutathione peroxidase (GPX) (12.2%, 8.8%) (p < 0.05), reduced glutathione (GSH) (17.6%, 10.1%) (p < 0.05), superoxide dismutase (SOD) (7.6%, 6.5%) (p < 0.05) and malondialdehyde (MDA) (10.3%, 9.6%) (p < 0.05), for both the placebo and caffeine groups respectively. In conclusion, our study highlighted that the consumption of 3 mg/kg caffeine could be an improving agent for the physical, cognitive, and psychological states without affecting the oxidative stress state during such a running competition.

Partial sleep deprivation affects endurance performance and psychophysiological responses during 12-minute self-paced running exercise.

PURPOSE: This study aimed to investigate the effects of partial sleep deprivation (PSD) on physical performance and psychophysiological responses during 12-minute self-paced running exercise. METHODS: Twenty runners (20.8±1.1 years, 70.6±4.9 kg, 175.1±3.9 cm) performed, in a randomized order, two running self-paced field exercises after a normal sleep night (CONT, bedtime from 22:30 h to 06:30 h) and one night of PSD (bedtime from 00:30 h to 04:30 h). Core temperature and motivation were recorded before exercise. Speed, covered distance, heart rate (HR), rating of perceived exertion (RPE) and respiratory parameters (i.e., minute ventilation (VE), oxygen uptake (VO2) and carbon dioxide production (VCO2)) were assessed during exercise. Blood lactate concentration [La] was assessed 2 min after exercise. Simple reaction time (SRT), mood and barrage test (BT) were assessed before and after exercise. RESULTS: Higher RPE (p=0.01, d=0.90) and lower physical performance (i.e., p=0.001, d=0.59 for running speed and p=0.01, d=0.7 and Δ (%)=-6% for covered distance), following PSD, were obtained compared to CONT. Similarly, PSD attenuated core temperature (p=0.01, d=0.84), HR (p=0.006, ɳp2=0.45), VE (p=0.001, ɳp2=0.73), VO2 (p=0.001, ɳp2=0.96), BT (p<0.0005, ɳp2=0.86), SRT (p=0.0009, ɳp2=0.44) and mood (p<0.0005). However, VCO2, [La] and motivation score were not affected by sleep conditions. CONCLUSION: The decrease of running performance and the increase of physical discomfort after PSD could be the origin of the lower cardio-respiratory responses to the 12-minute self-paced exercise. Effective strategies should be introduced to overcome the deterioration of physical performance and physiological responses after PSD.

Effect of Different Running Exercise Modalities on Post-Exercise Oxidative Stress Markers in Trained Athletes.

The aim of this study was to examine the effect of running exercise modality on oxidative stress. Thirteen endurance athletes (age: 21.46 ± 0.66 years) performed three different running exercise modalities (Continuous running exercise (CR): continuous running exercise at 75% of VO2max for 25 min; intermittent running exercise #1 (15/15): intermittent running protocol, 15 s running at 75% of VO2max, 15 s passive recovery, performed for 50 min; intermittent running exercise #2 (30/30): intermittent running protocol, 30 s running at 75% of VO2max, 30 s passive recovery, performed for 50 min) in a randomized order. Blood samples were drawn at rest and immediately after each running exercise and assessed for malondialdehyde (MDA), advanced oxidation protein products (AOPP), superoxide dismutase(SOD), and glutathione peroxidase (GPX) activities. MDA increased by 55% following 30/30 exercise (p < 0.01), while it remained unchanged with CR and15/15 exercise. SOD increased after CR (+13.9%, p < 0.05), and also remained unchanged after 15/15 (p > 0.05) and decreased after 30/30 (-19.7% p < 0.05). GPX and AOPP did not change after exercise in all experimental sessions (p > 0.05). In conclusion, 30/30 intermittent running induced higher lipid damages than the 15/15 and CR exercise. 15/15 intermittent exercise promoted a better balance between free radicals production and antioxidant defense compared to continuous exercise and intermittent 30/30 exercise.