Medicine and Health Sciences Commons^™

Cyp1a2 Genotype And Acute Effects Of Caffeine On Resistance Exercise, Jumping, And Sprinting Performance, Jozo Grgic, Craig Pickering, David Bishop, Brad J. Schoenfeld, Pavle Mikulic, Zeljko Pedisic

Publications and Research

Background: It has been suggested that polymorphisms within CYP1A2 impact inter-individual variation in the response to caffeine. The purpose of this study was to explore the acute effects of caffeine on resistance exercise, jumping, and sprinting performance in a sample of resistance-trained men, and to examine the influence of genetic variation of CYP1A2 (rs762551) on the individual variation in responses to caffeine ingestion.

Methods: Twenty-two men were included as participants (AA homozygotes n = 13; C-allele carriers n = 9) and were tested after the ingestion of caffeine (3 mg/kg of body mass) and a placebo. Exercise performance was assessed …

Effects Of A Ketogenic Diet On Body Compostion And Strength In Trained Women, Salvador Vargas-Molina, Jorge L. Petro, Ramón Romance, Richard B. Kreider, Brad J. Schoenfeld, Diego A. Bonilla, Javier Benítez-Porres

Publications and Research

Background: The effect of ketogenic diets (KD) on body composition in different populations has been investigated. More recently, some have recommended that athletes adhere to ketogenic diets in order to optimize changes in body composition during training. However, there is less evidence related to trained women. We aimed to evaluate the effect of a KD on body composition and strength in trained women following an eight-week resistance training (RT) program.

Methods: Twenty-one strength-trained women (27.6 ± 4.0 years; 162.1 ± 6.6 cm; 62.3 ± 7.8 kg; 23.7 ± 2.9 kg·m− 2) were randomly assigned to either a non-KD group (n …

Adora2a C Allele Carriers Exhibit Ergogenic Responses To Caffeine Supplementation, Jozo Grgic, Craig Pickering, David J. Bishop, Juan Del Coso, Brad J. Schoenfeld, Grant M. Tinsley, Zeljko Pedisic

Publications and Research

Caffeine's ergogenic effects on exercise performance are generally explained by its ability to bind to adenosine receptors. ADORA2A is the gene that encodes A2A subtypes of adenosine receptors. It has been suggested that ADORA2A gene polymorphisms may be responsible for the inter-individual variations in the effects of caffeine on exercise performance. In the only study that explored the influence of variation in ADORA2A—in this case, a common polymorphism (rs5751876)—on the ergogenic effects of caffeine on exercise performance, C allele carriers were identified as “non-responders” to caffeine. To explore if C allele carriers are true “non-responders” to the ergogenic effects of …

The Effects Of Caffeine Ingestion On Measures Of Rowing Performance: A Systematic Review And Meta-Analysis, Jozo Grgic, Francisco Javier Diaz-Lara, Juan Del Coso, Michael J. Duncan, Jason Tallis, Craig Pickering, Brad J. Schoenfeld, Pavle Mikulic

Publications and Research

The purpose of this paper was to conduct a systematic review and a meta-analysis of studies examining the acute effects of caffeine ingestion on measures of rowing performance. Crossover and placebo-controlled experiments that investigated the effects of caffeine ingestion on measures of rowing performance were included. The PEDro checklist was used to assess the methodological quality of the included studies. Seven studies of good and excellent methodological quality were included. None of the included studies examined on-water rowing. The majority of studies that were included in the meta-analysis used a 2000m rowing distance with only one using 1000m distance. Results …

Comparison Of Blood Lactate And Perceived Exertion Responses In Two Matched Time-Under- Tension Protocols, Salvador Vargas-Molina, Fernando Martín-Rivera, Diego A. Bonilla, Jorge L. Petro, Leandro Carbone, Ramón Romance, Manuel Dediego, Brad J. Schoenfeld, Javier Benítez-Porres

Publications and Research

Purpose: The aim of this study was to compare the concentration of blood lactate [bLa-] and the subjective perception of exertion of trained men in a moderate repetition protocol (MRP) versus a high repetition protocol (HRP) equated for time under tension.

Methods: A sample of 40 healthy young men (aged, 23.2 ± 4.0 years; height, 177.3 ± 7.0 cm; BMI, 24.3 ± 2.2) performed two sessions of 8 sets of bicep curls with a one-week recovery interval between the trials. In the HRP protocol, 20 repetitions were performed with a cadence of 2 seconds of eccentric and 1 …