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.

Effects of a 30 min nap opportunity on cognitive and short-duration high-intensity performances and mood states after a partial sleep deprivation night.

This study evaluated the effects of partial-sleep-deprivation (SDN) and a 30 min nap opportunity on physical and cognitive performances and mood states. Fourteen physically active students (BMI = 232.8 ± 0.4 kg/m2) performed the reaction time, the number cancellation (i.e., assessing vigilance) and the 5-m shuttle run tests and responded to the Profile of Mood States (POMS-f) questionnaire at 18h00 after a normal-sleep (NSN) and a SDN) and after two nap conditions (Nap and no-Nap) realized between 13h00 and 13h30. Vigilance and the reaction time were better after Nap compared to no-Nap opportunity following NSN and SDN and during NSN compared to SDN only during no-Nap. Total and peak distance during the 5-m shuttle run test were higher and the fatigue index was lower during Nap compared to no-Nap condition after NSN and SDN and during NSN compared to SDN during Nap and no-Nnap. Anxiety, fatigue, confusion, and depression were lower and vigour was higher during Nap compared to no-Nap after NSN and SDN and during NSN compared to SDN during Nap and no-Nap. In conclusion, a 30-min of nap opportunity helps to overcome the negative effect of SDN on mood states as well as physical and cognitive performances.

Effects of caffeine ingestion on the diurnal variation of cognitive and repeated high-intensity performances.

The purpose of this study was to evaluate the effects of caffeine ingestion on the daily variation of cognitive (i.e., reaction time (RT), attention) and repeated high-intensity exercise performances. Fifteen active males (age: 20 ±â€¯1 years, height: 174.3 ±â€¯4.3 cm, body-mass: 70.8 ±â€¯3.5 kg) performed cognitive and physical tasks under two different circumstances [after a placebo or caffeine ingestion (6 mg/kg of body-mass)] at six different time-of-day (07 h00, 09 h00, 11 h00, 13 h00, 15 h00 and 17 h00) in a randomized double-blind balanced crossover design. During each session, RT, attention and 5-m multiple shuttles run test' performances were recorded. During both the placebo and the caffeine conditions, a significant diurnal variation was found with improvement of cognitive performances recorded at 11 h00 (e.g., RT: 0.37 ±â€¯0.02-s and 0.36 ±â€¯0.02-s for placebo and caffeine respectively) and 17 h00 (e.g., RT: 0.37 ±â€¯0.02-s and 0.35 ±â€¯0.03-s for placebo and caffeine respectively) compared to (i.e., worst performances) 07 h00 (e.g., RT: 0.41 ±â€¯0.02-s and 0.38 ±â€¯0.02-s for placebo and caffeine respectively) and 13 h00 (e.g., RT: 0.41 ±â€¯0.02-s and 0.38 ±â€¯0.02-s for placebo and caffeine respectively) (p < 0.05). For physical performance, improved values were recorded at 17 h00 (e.g., total distance: 730.00 ±â€¯43.92-m and 733.93 ±â€¯43.08-m for placebo and caffeine respectively) compared to 07 h00 (e.g., total distance: 698.14 ±â€¯45.39-m and 709.21 ±â€¯43.78-m for placebo and caffeine respectively) (p < 0.05). Compared to placebo, cognitive (e.g., RT: by 6.4% at 07 h00, 4.1% at 09 h00, 3.4% at 11 h00, 6.0% at 13 h00, 3.8% at 15 h00 and 3.8% at 17 h00) and physical (e.g., total distance: 1.6% at 07 h00, 0.9% at 09 h00, 0.1% at 11 h00 (p > 0.05), 0.5% at 13 h00, 1.0% at 15 h00 and 0.5% at 17 h00) performances increased at all time-of-day (p < 0.05). In conclusion, cognitive and physical performances are time-of-day dependent and caffeine is an effective ergogenic aid to improves both cognitive and physical performances especially at the moment of their lowest values.

The effects of caffeine ingestion on the reaction time and short-term maximal performance after 36 h of sleep deprivation.

The aim of the present study was to investigate the effects of caffeine ingestion on cognitive and physical performances after 36h of sleep deprivation. In randomized order, thirteen healthy male physical education students (age: 21.1±1.1years, body mass: 77.1±7.2kg, height: 1.77±0.06m) completed four test sessions at 18:00h: after placebo or 5mg·kg(-1) of caffeine ingestion during a baseline night (RN) (bed time: from 22:30h to 07:00h) or a night of 36h of sleep deprivation (TSD). During each test session, participants performed the squat jump (SJ), the reaction time, and the 30-s Wingate tests (i.e., for the measurement of the peak (PP) and mean (MP) powers and the fatigue index (FI)). The results showed that PP and MP decreased and FI increased during the TSD compared to RN in the placebo condition (p<0.001). The caffeine ingestion improved PP after TSD compared to RN (p<0.001). SJ decreased significantly after the TSD compared to RN after both placebo and caffeine ingestions (p<0.001). However, SJ increased significantly after caffeine ingestion during RN and TSD (p<0.001). The reaction time increased significantly after TSD compared to RN (p<0.001). However, the reaction time decreased significantly after the caffeine ingestion only during the TSD (p<0.001). Therefore, caffeine is an effective strategy to counteract the effect of 36h of sleep loss on physical and cognitive performances.

Effects of morning caffeine' ingestion on mood States, simple reaction time, and short-term maximal performance on elite judoists.

PURPOSE: The purpose of the present study was to evaluate the ergogenic effect of caffeine ingestion on mood state, simple reaction time, and muscle power during the Wingate test recorded in the morning on elite Judoists. METHODS: TWELVE ELITE JUDOISTS (AGE: 21.08 ± 1.16 years, body mass: 83.75 ± 20.2 kg, height: 1.76 ±6.57 m) participated in this study. Mood states, simple reaction time, and muscle power during the Wingate test were measured during two test sessions at 07:00 h and after placebo or caffeine ingestion (i.e. 5 mg/kg). Plasma concentrations of caffeine were measured before (T0) and 1-h after caffeine' ingestion (T1) and after the Wingate test (T3). RESULTS: Our results revealed an increase of the anxiety and the vigor (P<0.01), a reduction of the simple reaction time (P<0.001) and an improvement of the peak and mean powers during the Wingate test. However, the fatigue index during this test was unaffected by the caffeine ingestion. In addition, plasma concentration of caffeine was significantly higher at T1 in comparison with T0. CONCLUSIONS: In conclusion, the results of this study suggest that morning caffeine ingestion has ergogenic properties with the potential to benefit performance, increase anxiety and vigor, and decrease the simple reaction time.