Caffeine reversal of sleep deprivation effects on alertness, mood and repeated sprint performances in physical education students

Effect of caffeine supplementation on anaerobic and aerobic performance in sleep-restricted male college soccer players

This study aimed to explore the effects of sleep restriction of ≤5 h within 24 h on anaerobic and aerobic performance in male college soccer players and evaluated the effects of acute supplementation of 3 mg⋅kg-1 caffeine on the aerobic and anaerobic performance of college male soccer players under sleep restriction.

METHODS

10 college male soccer players were recruited, and a randomized crossover experimental design was adopted. The subjects received three intervention treatments in a randomized crossover order: Normal sleep night (NSN), sleep restriction night supplemented with placebo (SRP), and sleep restriction night supplemented with 3 mg⋅kg-1 caffeine (SRC), and participated in the Running-Based Anaerobic Sprint Test (RAST) and 30-15 Intermittent Fitness Test (30-15IFT).

RESULTS

The main effect of the RAST and the 30-15IFT scores was significant (P<0.05). Post hoc analyses showed that the peak power, mean power, peak power/body mess, mean power/body mess, peak velocity mean velocity, fatigue index of the RAST, and the velocity of the intermittent fitness test (VIFT), maximal oxygen uptake (VO2max), and time to exhaustion (TTE) of the 30-15IFT in the SRP group were significantly lower than those of the NSN group (P < 0.05), and the total time of the RAST was significantly higher than that of the NSN group (P < 0.05); there were significant differences between the VIFT, VO2max and TTE indicators tested at 30-15IFT between the SRC group and the SRP group (P < 0.05). Still, other indicators had no significant differences (P > 0.05).

CONCLUSION

Sleep restriction harms the anaerobic repeated sprint and aerobic performance of college soccer players; acute supplementation of 3 mg⋅kg-1 of caffeine can effectively reduce the negative impact of insufficient sleep the night before on the aerobic endurance performance of college soccer players. Athletes or coaches should consider caffeine supplementation as a strategy to alleviate the negative impacts of sleep deprivation, but individual tolerance and potential side effects should be taken into account.

Acute caffeine supplementation offsets the impairment in 10-km running performance following one night of partial sleep deprivation: a randomized controlled crossover trial

INTRODUCTION

Whether acute caffeine supplementation can offset the negative effects of one-night of partial sleep deprivation (PSD) on endurance exercise performance is currently unknown.

METHODS

Ten healthy recreational male runners (age: 27 ± 6 years;V ˙ O 2 max : 61 ± 9 mL/kg/min) completed 4 trials in a balanced Latin square design, which were PSD + caffeine (PSD-Caf), PSD + placebo (PSD-Pla), normal sleep (NS) + caffeine (NS-Caf) and NS + placebo (NS-Pla). 3 and 8 h sleep windows were scheduled in PSD and NS, respectively. 10-km treadmill time trial (TT) performance was assessed 45 min after caffeine (6 mg/kg/body mass)/placebo supplementation in the morning following PSD/NS. Blood glucose, lactate, free fatty acid and glycerol were measured at pre-supplementation, pre-exercise and after exercise.

RESULTS

PSD resulted in compromised TT performance compared to NS in the placebo conditions by 5% (51.9 ± 7.7 vs. 49.4 ± 6.9 min, p = 0.001). Caffeine improved TT performance compared to placebo following both PSD by 7.7% (PSD-Caf: 47.9 ± 7.3 min vs. PSD-Pla: 51.9 ± 7.7 min, p = 0.007) and NS by 2.8% (NS-Caf: 48.0 ± 6.4 min vs. NS-Pla: 49.4 ± 6.9 min, p = 0.049). TT performance following PSD-Caf was not different from either NS-Pla or NS-Caf (p = 0.185 and p = 0.891, respectively). Blood glucose, lactate, and glycerol concentrations at post-exercise, as well as heart rate and the speed/RPE ratio during TT, were higher in caffeine trials compared to placebo.

CONCLUSIONS

Caffeine supplementation offsets the negative effects of one-night PSD on 10-km running performance.

Impact of one night of sleep restriction on sleepiness and cognitive function: A systematic review and meta-analysis

Detrimental consequences of chronic sleep restriction on cognitive function are well established in the literature. However, effects of a single night of sleep restriction remain equivocal. Therefore, we synthesized data from 44 studies to investigate effects of sleep restriction to 2-6 h sleep opportunity on sleepiness and cognition in this meta-analysis. We investigated subjective sleepiness, sustained attention, choice reaction time, cognitive throughput, working memory, and inhibitory control. Results revealed a significant increase in subjective sleepiness following one night of sleep restriction (Standardized Mean Difference (SMD) = 0.986, p < 0.001), while subjective sleepiness was not associated with sleep duration during sleep restriction (β = -0.214, p = 0.039, significance level 0.01). Sustained attention, assessed via common 10-min tasks, was impaired, as demonstrated through increased reaction times (SMD = 0.512, p < 0.001) and attentional lapses (SMD = 0.489, p < 0.001). However, the degree of impaired attention was not associated with sleep duration (ps > 0.090). We did not find significant effects on choice reaction time, cognitive throughput, working memory, or inhibitory control. Overall, results suggest that a single night of restricted sleep can increase subjective sleepiness and impair sustained attention, a cognitive function crucial for everyday tasks such as driving.

Effects of Different Caffeine Dosages on Maximal Physical Performance and Potential Side Effects in Low-Consumer Female Athletes: Morning vs. Evening Administration

While previous studies have explored a range of factors governing the optimal use of caffeine (CAF) in athletes, limited research has explored how time of day (TOD) affects the ergogenic effects of various CAF dosages on physical performance. This study aimed to increase knowledge about how different recommended CAF doses (3 mg/kg vs. 6 mg/kg) ingested at different TODs affected maximal high-intensity physical performance and the perception of potential side effects in female athletes. In this double-blind, randomized, and counterbalanced study, 15 low CAF consumer athletes (aged 18.3 ± 0.5 y) underwent six trials, including three testing conditions assessed across two TODs: one in the morning (08:00 a.m.) and one in the evening (06:00 p.m.). During each condition, the participants ingested either a placebo, 3 mg/kg CAF (CAF (3 mg)), or 6 mg/kg CAF (CAF (6 mg)) capsules 60 min before each test with an in-between washout period of at least 72 h. In each trial, the participants performed a countermovement jumps test (CMJ), a modified agility t test (MATT), a repeated sprint ability (RSA), a rating of perceived exertion (RPE), and finally, a CAF side effects questionnaire. Our findings indicate the absence of an ergogenic effect on CMJ, MAT, and RSA performance in the evening after administering CAF (3 mg) or CAF (6 mg) compared to a placebo. Likewise, when CAF was ingested in the morning, there was an improvement in these performances with both CAF (3 mg) and CAF (6 mg), with greater improvement observed after CAF (6 mg). Additionally, neither the CAF dosage nor the TOD had a significant effect on the RPE. The occurrence of side effects increased significantly after the evening ingestion of CAF, particularly with a moderate dose of CAF (6 mg). Our findings indicate that the effectiveness of CAF depends on the TOD and CAF dosage. When ingested in the morning, a moderate dose of CAF (6 mg), rather than CAF (3 mg), is more effective in improving short-term physical performance without affecting CAF side effects in female athletes. Nevertheless, when ingested in the evening, neither dose was sufficient to enhance short-term physical performance, and both dosages increased the incidence of CAF side effects, particularly at a moderate dose.

Effects of Acute Sleep Deprivation on Sporting Performance in Athletes: A Comprehensive Systematic Review and Meta-Analysis

Objective

Using meta-analysis to comprehensively and quantitatively evaluate the impact of acute sleep deprivation on different sports performance of athletes, this study aims to provide scientific guidance for coaches in optimizing and adjusting training and competition arrangements.

Methods

Establishing literature inclusion and exclusion criteria, we conducted searches in both Chinese and English databases. Using stata 14.0, we analyzed 75 indicators from 27 included literature, focusing on three aspects: the impact of acute sleep deprivation on overall athletic performance, the impact on sporting performance across various athletic abilities, and the disparities in athletic performance between morning and afternoon following acute sleep deprivation.

Results

The effect size of acute sleep deprivation on overall athletic performance was -0.56 (P<0.05). Sub-analyses revealed effect sizes of -0.23 (P<0.05) for whole night sleep deprivation, -1.17 (P<0.05) for partial sleep deprivation at the end of the night, and -0.25 (P>0.05) for partial sleep deprivation in the beginning of the night. The effect sizes of acute sleep deprivation on high intensity intermittent exercise, skill control, speed, aerobic endurance, and explosive power indicators were -1.57, -1.06, -0.67, -0.54, and -0.39 respectively (P<0.05). The effect sizes of acute sleep deprivation on the overall athletic performance in the morning and afternoon were -0.30, and -1.11, respectively (P<0.05).

Conclusion

Acute sleep deprivation significantly impairs the overall athletic performance of athletes, with a more pronounced negative impact observed with partial sleep deprivation at the end of the night. Various types of exercise performance are adversely affected by acute sleep deprivation, with magnitude of impact ranking high intensity intermittent, skill control, speed, aerobic endurance, and explosive power. Following acute sleep deprivation, athletes' overall sporting performance in the afternoon is inferior to that in the morning.

Pre-Exercise Caffeine Intake Attenuates the Negative Effects of Ramadan Fasting on Several Aspects of High-Intensity Short-Term Maximal Performances in Adolescent Female Handball Players

The aim of this investigation was to determine whether, after Ramadan, pre-exercise caffeine intake can reduce any possible negative effects of this month on short-term maximal performances in young female handball players. A randomized study involved thirteen young female handball players. Participants performed a squat jump (SJ), Illinois agility test (AG), and 5 m run shuttles test (total (TD) and peak (PD) distances) at 08:00 AM and 06:00 PM on three different occasions: one week before Ramadan (Pre-R), the last week of Ramadan (R), and the week after Ramadan (Post-R). A placebo (Pla) or caffeine (Caff) (6 mg·kg-1) was administered 60 min before exercise test sessions at two distinct times of day (08:00 AM and 06:00 PM) during the two periods: Pre and Post-R. The PSQI and dietary intake were assessed during all testing periods. The results revealed that Pre-R, (SJ, AG, TD, and PD) test performances were greater in the evening (PM) than in the morning (AM) (all p < 0.001). However, compared with Pre-R, PM performances declined significantly during R (all p < 0.001) and Post-R (p < 0.05, p < 0.01, p < 0.01 and p < 0.001, respectively). In addition, Pre-R, AM Caff produced moderate significant improvements compared with AM Pla, with small-to-no beneficial effects observed with PM Caff in SJ (4.8% vs. 1%), AG (1.8% vs. 0.8%), TD (2.8% vs. 0.3%), and PD (6% vs. 0.9%). Nevertheless, Caff produced moderate ergogenic effects during both AM and PM sessions during Post-R in SJ (4.4% vs. 2.4%), AG (1.7% vs. 1.5%), TD (2.9% vs. 1.3%), and PD (5.8% vs. 3%) with values approaching those of Pre-R Pla within the same time of day (p > 0.05, p > 0.05, p < 0.05, and p < 0.05, respectively). In summary, pre-exercise Caff intake with a dose equivalent to 6 mg·kg-1 reduced the negative effects of Ramadan fasting in several aspects of short-term maximal performances in young female handball players at both times of the day.

Effects of Acute Sleep Loss on Physical Performance: A Systematic and Meta-Analytical Review

BACKGROUND

Sleep loss may influence subsequent physical performance. Quantifying the impact of sleep loss on physical performance is critical for individuals involved in athletic pursuits.

DESIGN

Systematic review and meta-analysis.

SEARCH AND INCLUSION

Studies were identified via the Web of Science, Scopus, and PsycINFO online databases. Investigations measuring exercise performance under 'control' (i.e., normal sleep, > 6 h in any 24 h period) and 'intervention' (i.e., sleep loss, ≤ 6 h sleep in any 24 h period) conditions were included. Performance tasks were classified into different exercise categories (anaerobic power, speed/power endurance, high-intensity interval exercise (HIIE), strength, endurance, strength-endurance, and skill). Multi-level random-effects meta-analyses and meta-regression analyses were conducted, including subgroup analyses to explore the influence of sleep-loss protocol (e.g., deprivation, restriction, early [delayed sleep onset] and late restriction [earlier than normal waking]), time of day the exercise task was performed (AM vs. PM) and body limb strength (upper vs. lower body).

RESULTS

Overall, 227 outcome measures (anaerobic power: n = 58; speed/power endurance: n = 32; HIIE: n = 27; strength: n = 66; endurance: n = 22; strength-endurance: n = 9; skill: n = 13) derived from 69 publications were included. Results indicated a negative impact of sleep loss on the percentage change (%Δ) in exercise performance (n = 959 [89%] male; mean %Δ =  - 7.56%, 95% CI - 11.9 to - 3.13, p = 0.001, I2 = 98.1%). Effects were significant for all exercise categories. Subgroup analyses indicated that the pattern of sleep loss (i.e., deprivation, early and late restriction) preceding exercise is an important factor, with consistent negative effects only observed with deprivation and late-restriction protocols. A significant positive relationship was observed between time awake prior to the exercise task and %Δ in performance for both deprivation and late-restriction protocols (~ 0.4% decrease for every hour awake prior to exercise). The negative effects of sleep loss on different exercise tasks performed in the PM were consistent, while tasks performed in the AM were largely unaffected.

CONCLUSIONS

Sleep loss appears to have a negative impact on exercise performance. If sleep loss is anticipated and unavoidable, individuals should avoid situations that lead to experiencing deprivation or late restriction, and prioritise morning exercise in an effort to maintain performance.

Acute Effects of Caffeine Supplementation on Physical Performance, Physiological Responses, Perceived Exertion, and Technical-Tactical Skills in Combat Sports: A Systematic Review and Meta-Analysis

Although the effects of caffeine supplementation on combat sports performance have been extensively investigated, there is currently no consensus regarding its ergogenic benefits.This systematic review with meta-analysis aimed to summarize the studies investigating the effects of caffeine supplementation on different aspects of performance in combat sports and to quantitatively analyze the results of these studies to better understand the ergogenic effect of caffeine on combat sports outcomes. A systematic search for randomized placebo-controlled studies investigating the effects of caffeine supplementation on combat sports' performance was performed through Scopus, Pubmed, Web of Science and Cochrane Library databases up to 18 April 2022. Random-effects meta-analyses of standardized mean differences (Hedge's g) were performed to analyze the data. Twenty-six studies of good and excellent methodological quality (based on the Pedro scale) fulfilled the inclusion criteria. The meta-analysis results revealed caffeine has a small but evident effect size (ES) on handgrip strength (ES = 0.28; 95% CI: 0.04 to 0.52; p = 0.02), and total number of throws during the special judo fitness test (SJFT) (ES = 0.42; 95% CI: 0.06 to 0.78; p = 0.02). Regarding the physiological responses, caffeine increased blood lactate concentration ([La]) in anaerobic exercise (ES = 1.23; 95% CI: 0.29 to 2.18; p = 0.01) and simulated combat (ES = 0.91; 95% CI: 0.34 to 1.47; p = 0.002). For Heart Rate (HR), caffeine increased HR final (ES = 0.31; 95% CI: 0.11 to 0.52; p = 0.003), and HR 1min (ES = 0.20; 95% CI 0.004 to 0.40; p = 0.045). However, caffeine had no impact on the countermovement jump height, the SJFT index, the judogi strength-endurance test, the number and duration of offensive actions, HR at the end of the fight, and the rating of perceived exertion. Caffeine supplementation may be ergogenic for a range of combat sports aspects involving isometric strength, anaerobic power, reaction time, and anaerobic metabolism. However, supplementation effects might be ineffective under certain circumstances, indicating supplementation needs to take into account the performance metric in question prior to creating a dosing protocol.

Sleep Restriction in Elite Soccer Players: Effects on Explosive Power, Wellbeing, and Cognitive Function

Purpose: To investigate the cognitive, physical, and perceptual effects of sleep restriction (SR) in soccer players following a night match. Methods: In a crossover design, nine male soccer players from the English Premier League 2 (age, 21 ± 5 years; height, 1.80 ± 0.75 m; body mass, 74.2 ± 6.8 kg) recorded their sleep quality and quantity with sleep logs and a subjective survey after two night matches (19:00); one where sleep duration was not altered (CON) and one where sleep was restricted by a later bed-time (SR). Countermovement jump height (CMJ), subjective wellbeing (1-5 likert scale for mood, stress, fatigue, sleep, and soreness), and cognitive function were measured at baseline and the morning following the match (+12 h; M + 1). Results: Bed-time was later in SR than CON (02:36 ± 0.17 vs. 22:43 ± 29; P = .0001; ηp² = 0.999) and sleep duration was shorter in SR than CON (5.37 ± 0.16 vs. 8.59 h ± 0.36; P = .0001; ηp² = 0.926). CMJ decreased by ~8% after the match in both SR and CON (P = .0001; ηp² = 0.915) but there were no differences between the conditions (P > .05; ηp² = 0.041-0.139). Wellbeing was rated worse after both matches (P = .0001; ηp² = 0.949) but there were no differences between the trials (P > .05; ηp² = 0.172-257). SR did not influence cognitive function (P > .05; interaction effects, ηp² = 0.172-257). Conclusion: SR following a nighttime soccer match does not impair CMJ performance, subjective wellbeing, or cognitive function the following morning.

The Effect of Experimental Recuperative and Appetitive Post-lunch Nap Opportunities, With or Without Caffeine, on Mood and Reaction Time in Highly Trained Athletes

Purpose: To investigate the effects of placebo (PLA), 20 min nap opportunity (N20), 5mg·kg-1 of caffeine (CAF), and their combination (CAF+N20) on sleepiness, mood and reaction-time after partial sleep deprivation (PSD; 04h30 of time in bed; study 1 ) or after normal sleep night (NSN; 08h30 of time in bed; study 2 ). Methods: Twenty-three highly trained athletes ( study 1 ; 9 and study 2 ; 14) performed four test sessions (PLA, CAF, N20 and CAF+N20) in double-blind, counterbalanced and randomized order. Simple (SRT) and two-choice (2CRT) reaction time, subjective sleepiness (ESS) and mood state (POMS) were assessed twice, pre- and post-intervention. Results: SRT was lower (i.e., better performance) during CAF condition after PSD (pre: 336 ± 15 ms vs. post: 312 ± 9 ms; p < 0.001; d = 2.07; Δ% = 7.26) and NSN (pre: 350 ± 39 ms vs. post: 323 ± 32 ms; p < 0.001; d = 0.72; Δ% = 7.71) compared to pre-intervention. N20 decreased 2CRT after PSD (pre: 411 ± 13 ms vs. post: 366 ± 20 ms; p < 0.001; d = 2.89; Δ% = 10.81) and NSN (pre: 418 ± 29 ms vs. post: 375 ± 40 ms; p < 0.001; d = 1.23; Δ% = 10.23). Similarly, 2CRT was shorter during CAF+N20 sessions after PSD (pre: 406 ± 26 ms vs. post: 357 ± 17 ms; p < 0.001; d = 2.17; Δ% = 12.02) and after NSN (pre: 386 ± 33 ms vs. post: 352 ± 30 ms; p < 0.001; d = 1.09; Δ% = 8.68). After PSD, POMS score decreased after CAF (p < 0.001; d = 2.38; Δ% = 66.97) and CAF+N20 (p < 0.001; d = 1.68; Δ% = 46.68). However, after NSN, only N20 reduced POMS (p < 0.001; d = 1.05; Δ% = 78.65) and ESS (p < 0.01; d = 0.71; Δ% = 19.11). Conclusion: After PSD, all interventions reduced sleepiness and only CAF enhanced mood with or without napping. However, only N20 enhanced mood and reduced sleepiness after NSN. Caffeine ingestion enhanced SRT performance regardless of sleep deprivation. N20, with or without caffeine ingestion, enhanced 2CRT independently of sleep deprivation. This suggests a different mode of action of napping and caffeine on sleepiness, mood and reaction time.

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.