Shona L. Halson and David T. Martin
Neil D. Clarke and Darren L. Richardson
There is growing evidence that caffeine and coffee ingestion prior to exercise provide similar ergogenic benefits. However, there has been a long-standing paradigm that habitual caffeine intake may influence the ergogenicity of caffeine supplementation. The aim of the present study was to investigate the effect of habitual caffeine intake on 5-km cycling time-trial performance following the ingestion of caffeinated coffee. Following institutional ethical approval, in a double-blind, randomized, crossover, placebo-controlled design, 46 recreationally active participants (27 men and 19 women) completed a 5-km cycling time trial on a cycle ergometer 60 m in following the ingestion of 0.09 g/kg coffee providing 3 mg/kg of caffeine, or a placebo. Habitual caffeine consumption was assessed using a caffeine consumption questionnaire with low habitual caffeine consumption defined as <3 and ≥6 mg · kg−1 · day−1 defined as high. An analysis of covariance using habitual caffeine intake as a covariant was performed to establish if habitual caffeine consumption had an impact on the ergogenic effect of coffee ingestion. Sixteen participants were classified as high-caffeine users and 30 as low. Ingesting caffeinated coffee improved 5-km cycling time-trial performance by 8 ± 12 s; 95% confidence interval (CI) [5, 13]; p < .001; d = 0.30, with low, 9±14 s; 95% CI [3, 14]; p = .002; d = 0.18, and high, 8 ± 10 s; 95% CI [−1, 17]; p = .008; d = 0.06, users improving by a similar magnitude, 95% CI [−12, 12]; p = .946; d = 0.08. In conclusion, habitual caffeine consumption did not affect the ergogenicity of coffee ingestion prior to a 5-km cycling time trial.
George P. Robinson, Sophie C. Killer, Zdravko Stoyanov, Harri Stephens, Luke Read, Lewis J. James and Stephen J. Bailey
This study investigated whether supplementation with nitrate-rich beetroot juice (BR) can improve high-intensity intermittent running performance in trained males in normoxia and different doses of normobaric hypoxia. Eight endurance-trained males (
Sophia Nimphius and Matthew J. Jordan
Chung-Ju Huang, Hsin-Yu Tu, Ming-Chun Hsueh, Yi-Hsiang Chiu, Mei-Yao Huang and Chien-Chih Chou
This study examined the effects of acute aerobic exercise on sustained attention and discriminatory ability of children with and without learning disabilities (LD). Fifty-one children with LD and 49 typically developing children were randomly assigned to exercise or control groups. The participants in the exercise groups performed a 30-min session of moderate-intensity aerobic exercise, whereas the control groups watched a running/exercise-related video. Neuropsychological tasks, the Daueraufmerksamkeit sustained attention test, and the determination tests were assessed before and after each treatment. Exercise significantly benefited performance in sustained attention and discriminatory ability, particularly in higher accuracy rate and shorter reaction time. In addition, the LD exercise group demonstrated greater improvement than the typically developing exercise group. The findings suggest that the acute aerobic exercise influenced the sustained attention and the discriminatory function in children with LD by enhancing regulation of mental states and allocation of attentional resources.
Giuseppe delli Paoli, Denise van de Laarschot, Edith C.H. Friesema, Remco Verkaik, Antonia Giacco, Rosalba Senese, Pascal P. Arp, P. Mila Jhamai, Stefano M. Pagnotta, Linda Broer, André G. Uitterlinden, Antonia Lanni, M. Carola Zillikens and Pieter de Lange
Fasting enhances the beneficial metabolic outcomes of exercise; however, it is unknown whether body composition is favorably modified on the short term. A baseline–follow-up study was carried out to assess the effect of an established protocol involving short-term combined exercise with fasting on body composition. One hundred seven recreationally exercising males underwent a 10-day intervention across 15 fitness centers in the Netherlands involving a 3-day gradual decrease of food intake, a 3-day period with extremely low caloric intake, and a gradual 4-day increase to initial caloric intake, with daily 30-min submaximal cycling. Using dual-energy X-ray absorptiometry analysis, all subjects substantially lost total body mass (−3.9 ± 1.9 kg; p < .001) and fat mass (−3.3 ± 1.3 kg; p < .001). Average lean mass was lost (−0.6 ± 1.5 kg; p < .001), but lean mass as a percentage of total body mass was not reduced. The authors observed a loss of −3.9 ± 1.9% android fat over total fat mass (p < .001), a loss of −2.2 ± 1.9% gynoid over total fat mass (p < .001), and reduced android/gynoid ratios (−0.05 ± 0.1; p < .001). Analyzing 15 preselected single-nucleotide polymorphisms in 13 metabolism-related genes revealed trending associations for thyroid state–related single-nucleotide polymorphisms rs225014 (deiodinase 2) and rs35767 (insulin-like growth factor1), and rs1053049 (PPARD). In conclusion, a short period of combined fasting and exercise leads to a substantial loss of body and fat mass without a loss of lean mass as a percentage of total mass.
Nicola Luigi Bragazzi, Kayvan Khoramipour, Anis Chaouachi and Karim Chamari
James A. Betts
Nicholas A. Koemel, Christina M. Sciarrillo, Katherine B. Bode, Madison D. Dixon, Edralin A. Lucas, Nathaniel D.M. Jenkins and Sam R. Emerson
The consumption of a high-fat meal can induce postprandial lipemia and endothelial dysfunction. The authors assessed the impact of age and physical activity on metabolic and vascular outcomes following meal consumption in healthy adults. The authors recruited four groups: younger active (age 22.1 ± 1.4 years; n = 9), younger inactive (age 22.6 ± 3.7 years; n = 8), older active (age 68.4 ± 7.7 years; n = 8), and older inactive (age 67.7 ± 7.2 years; n = 7). The metabolic outcomes were measured at the baseline and hourly for 6 hr post high-fat meal consumption (12 kcal/kg; 63% fat). Flow-mediated dilation was measured at the baseline, 2 hr, and 4 hr postmeal. The total area under the curve for triglycerides was significantly lower in the more active groups, but did not differ based on age (younger active = 6.5 ± 1.4 mmol/L × 6 hr, younger inactive = 11.7 ± 4.8, older active = 6.8 ± 2.7, older inactive = 12.1 ± 1.7; p = .0004). After adjusting for artery diameter, flow-mediated dilation differed between groups at the baseline (younger active = 4.8 ± 1.6%, younger inactive = 2.5 ± 0.5, older active = 3.4 ± 0.9, older inactive = 2.2 ± 0.4; p < .001) and decreased significantly across groups 4 hr postmeal (mean difference = 0.82; 95% CI [0.02, 1.6]; p = .04). These findings highlight the beneficial effect of regular physical activity on postprandial lipemia, independent of age.