Guarana (Paullinia cupana) but Not Low-Dose Caffeine Improves Cycling Time-Trial Performance Versus Placebo.

Guarana (GUA) seed extract, containing caffeine (CAF) and additional bioactive compounds, may positively affect mental performance, but evidence regarding exercise is limited. This investigation assessed acute GUA ingestion compared with CAF on endurance performance. Eleven endurance-trained noncyclists and cyclists (V˙O2peak = 49.7 ± 5.9, 60.4 ± 4.6 ml·kg·min-1) completed a double-blind, crossover experiment after ingesting (a) 100 mg CAF, (b) 500 mg GUA (containing 130 mg CAF), or (c) placebo (P) prior to 60-min fixed cycling workload (FIX) + 15-min time trial. Oxygen uptake, heart rate, respiratory exchange ratio, blood glucose, and lactate were not different (p ≥ .052) during FIX. A significant interaction (p = .042) for perceived exertion was observed at 50-min FIX with lower rating (p = .023) for GUA versus CAF but not compared with P. Work accumulated over 15-min time trial was greater (p = .038) for GUA versus P due to higher early (1-11 min) work outputs. Work performance favored (effect size = 0.18; 95% confidence interval [0.003, 0.355], p = .046) GUA (241.4 ± 39.9 kJ) versus P (232.1 ± 46.6 kJ), but CAF (232.3 ± 43.9) was not different from GUA (effect size = 0.19; 95% confidence interval [-0.022, 0.410], p = .079) or P. Postexercise strength loss was not attenuated with GUA (-5.6 ± 8.5%) or CAF (-8.3 ± 9.4%) versus P (-10.3 ± 5.1%). Acute GUA ingestion improved work performance relative to P, but effects were trivial to small and unrelated to altered substrate oxidation or muscular strength. Ergogenicity may involve central mechanisms reducing perceived effort with GUA (containing 130 mg caffeine). Due to issues related to identical matching of dosage, whether GUA confers additional benefits beyond its CAF content cannot be determined at present.

Influence of Mental Fatigue on Physical Performance, and Physiological and Perceptual Responses of Judokas Submitted to the Special Judo Fitness Test.

ABSTRACT: Campos, BT, Penna, EM, Rodrigues, JGS, Mendes, TT, Maia-Lima, A, Nakamura, FY, Vieira, ÉLM, Wanner, SP, and Prado, LS. Influence of mental fatigue on physical performance, and physiological and perceptual responses of judokas submitted to the Special Judo Fitness Test. J Strength Cond Res 36(2): 461-468, 2022-Mentally fatigued athletes present impaired aerobic performance, strength endurance, and manual dexterity, despite no changes in anaerobic performance and maximal muscle strength and power. Noteworthy, the effect of mental fatigue on physical performance during high-intensity intermittent tests that require specific motor skills of fighting sports has not been investigated. Therefore, this study aimed to verify whether mental fatigue influences performance and physiological and perceptual responses of judokas subjected to a high-intensity intermittent test designed specifically and validated for judo. Each judoka performed 2 experimental trials-a control trial one and the other one after the induction of mental fatigue. These trials were scheduled in a random and balanced order. In both trials, lactate, glucose, and cortisol concentrations, the heart rate variability, and perceptual variables were collected after the initial treatment and after the Special Judo Fitness Test (SJFT). The initial treatment consisted of a 30-minute cognitive demanding task (Stroop Color test) or watching a movie (control) and was followed by the SJFT. The Stroop Color test increased the perceptions of mental fatigue and effort, without affecting motivation for subsequent testing. Unexpectedly, mentally fatigued athletes did not show reduced performance during the SJFT. Regarding the physiological variables, no significant differences were identified between the 2 experimental conditions. We conclude that physical performance measured during a specific test for judokas is not impaired by a previous 30-minute cognitive task that causes mental fatigue. In addition, this cognitive task did not influence the physiological changes induced by the specific physical test.

Neuromuscular and physiological responses to different training loads in Randori of elite judo athletes

Abstract Aim: To compare two different randori structure (high volume and short pauses - TRAD training vs low volume with long pauses - COMP training) in the neuromuscular and metabolic responses of elite judo athletes. Methods: The first situation (TRAD) consisted of 12 randoris of 5 minutes with 45 seconds rest, and the other situation (COMP), consisted of 6 randoris of 5 minutes with 10 minutes between them. Physiological (Blood Lactate and Creatine Kinase), neuromuscular (Countermovement Jump and Medicine Ball Throws) and perceptive variables (Rating Perceived Exertion) were measured before and at the end of the sessions. Results: The subjective perception of effort at the end of the training was significantly higher in the TRAD training type (TRADpost: 8.1 ± 0.9 AU; COMPpost: 6.6 ± 1.5 AU, p <0.001). Blood lactate concentration (TRADpost: 6.4 ± 2.2 mmol/L; COMPpost: 8.1 ± 2.9 mmol/L; p <0.001), CMJ height (TRADpost: 36.2 ± 4.6 cm; COMPpost: 35.9 ± 4.3 cm, p = 0.012) and upper limb power performance (TRADpost: 6.4 ± 0.9 m; COMPpost: 6.3 ± 0.9 m p = 0.03) were significantly higher at the end of the two training sessions compared to their start, but there are no group effect. There is group effect in CK (TRADpost: 490.7 ± 273.5 U/L; COMPpost: 357.4 ± 203.8 U/L; p <0.001). Conclusions: This study demonstrated that TRAD and COMP Judo training induced similar physical demands, and both seem to not be enough to reach higher intensities, which made them distant methods of competitive reality.