Biology subjects

Andrade-Souza, V. A.

Publications and source records attributed to Andrade-Souza, V. A..

2 recordsLinked to original sources

bioRxiv2019

Caffeine but not acetaminophen increases 4-km cycling time-trial performance

Acetaminophen has been combined with caffeine for therapeutic purpose, but the effect of co-ingestion of acetaminophen and caffeine on exercise performance has not been investigated. The aim of this study was to determine the effect of isolated and combined ingestion of caffeine and acetaminophen on performance during a 4-km cycling time-trial. In a double-blind, crossover design, eleven men, accustomed to cycling recreationally, completed a 4-km cycling time-trial one hour after the ingestion of cellulose (PLA), acetaminophen (20 mg{middle dot}kg-1 body mass, ACT), caffeine (5 mg{middle dot}kg-1 body mass, CAF) or combined acetaminophen and caffeine (20 and 5 mg{middle dot}kg-1 body mass, respectively, ACTCAF). The perception of pain and rating of perceived exertion were recorded every 1-km, and electromyography and oxygen uptake were continually recorded and averaged each 1-km. Plasma lactate concentration was measured before and immediately after the trial. The time and mean power during the 4-km cycling time-trial was significantly improved (P < 0.05) in CAF (407.9 {+/-} 24.5 s, 241.4 {+/-} 16.1 W) compared to PLA (416.1 {+/-} 34.1 s, 234.1 {+/-} 19.2 W) and ACT (416.2 {+/-} 26.6 s, 235.8 {+/-} 19.7 W). However, there was no difference between ACTCAF (411.6 {+/-} 27.7 s, 238.7 {+/-} 18.7 W) and the other conditions (P > 0.05). The perception of pain, rating of perceived exertion, electromyography, oxygen uptake, and plasma lactate were similar across the conditions (P > 0.05). In conclusion, caffeine but not acetaminophen increases power output ultimately increasing performance during a 4-km cycling time-trial.

physiology↗

bioRxiv2019

Exercise twice-a-day potentiates skeletal muscle signalling responses associated with mitochondrial biogenesis in humans, which are independent of lowered muscle glycogen content

Endurance exercise begun with reduced muscle glycogen stores seems to potentiate skeletal muscle protein abundance and gene expression. However, it is unknown whether this greater signalling responses is due to low muscle glycogen per se or to performing two exercise sessions in close proximity - as a first exercise session is necessary to reduce the muscle glycogen stores. In the present study, we manipulated the recovery duration between a first muscle glycogen-depleting exercise and a second exercise session, such that the second exercise session started with reduced muscle glycogen in both approaches but was performed either two or 15 h after the first exercise session (so-called "twice-a-day" and "once-daily" approaches, respectively). We found that exercise twice-a-day increased the nuclear abundance of transcription factor EB (TFEB) and nuclear factor of activated T cells (NFAT) and potentiated the transcription of peroxisome proliferator-activated receptor-coactivator 1 alpha (PGC-1), peroxisome proliferator-activated receptor alpha (PPAR) and peroxisome proliferator-activated receptor beta/delta (PPAR{beta}/{delta}) genes, in comparison with the once-daily exercise. These results suggest that the elevated molecular signalling reported with previous "train-low" approaches can be attributed to performing two exercise sessions in close proximity rather than the reduced muscle glycogen content per se. The twice-a-day approach might be an effective strategy to induce adaptations related to mitochondrial biogenesis and fat oxidation.

molecular biology↗