Background Theacrine (1,3,7,9-tetramethyluric-acid) is a pure alkaloid with a similar structure to caffeine and acts comparably as an adenosine receptor antagonist. Early studies have shown non-habituating effects, including increases in energy and focus in response to Teacrine®, the compound containing pure theacrine. The purpose of this study was to determine and compare the effects of Teacrine® and caffeine on cognitive performance and time-to-exhaustion during a simulated soccer game in high-level male and female athletes. Methods Male and female soccer players ( N = 24; M Age = 20.96 ± 2.05y, M MaleVO2max = 55.31 ± 3.39 mL/O 2 /kg, M FemaleVO2max = 50.97 ± 3.90 mL/O 2 /kg) completed a 90-min simulated treadmill soccer match over four randomized sessions (TeaCrine®, caffeine, TeaCrine® + caffeine, placebo). Cognitive testing at halftime and end-of-game including simple reaction time (SRT), choice RT (CRT), and cognitive-load RT with distraction questions (COGRT/COGRT Wrong ) was performed, with a run time-to-exhaustion (TTE) at 85% VO 2max following end-of-game cognitive testing. Session times and pre-exercise nutrition were controlled. RM-MANOVAs with univariate follow-ups were conducted and significance was set at P < 0.05. Results TTE trended towards significance in TeaCrine® and TeaCrine® + caffeine conditions compared to placebo ( P < 0.052). A condition main effect ( P < 0.05) occurred with faster CRT in caffeine and TeaCrine® + caffeine compared to placebo. COGRT Wrong showed a significant time main effect, with better accuracy at end-of-game compared to halftime ( P < 0.05). A time x condition interaction in SRT ( P < 0.05) showed placebo improved from halftime to end-of-game. Conclusions The 27–38% improvements in TTE reflect increased performance capacity that may have important implications for overtime scenarios. These findings suggest TeaCrine® favorably impacts endurance and the combination with caffeine provides greater benefits on cognitive function than either supplement independently.

The purpose of this study was to evaluate the effects of a competitive soccer season on biomarkers and performance metrics in order to determine the correlation between changes in biomarkers, body composition, and performance outcomes. Twenty-one Division 1 female collegiate soccer players were monitored throughout the 16-week season. Player workload was measured using heart rate and Global Position Satellite systems at all practices and games. Performance testing, including vertical jump, VO 2max , and 3-repetition maximum testing for bench press, squat and deadlift, occurred prior to pre-season and immediately post-season. Blood draws occurred prior to preseason and every 4-weeks thereafter, following a game. Body composition was assessed prior to the start of season (week 0) and weeks 6, 10, 14, and 17 (post-season). Delta area under the curve was calculated for biomarkers and body composition variables to account for seasonal changes adjusted for baseline. Pearson-product moment correlations were used to assess relationships with significance set at p < 0.05. Trends were considered p ≤ 0.10. No significant time main effects were seen for anabolic biomarkers (p > 0.05). Significant time effects were seen for catabolic biomarkers throughout the season (p = 0.001). No changes in body weight, VO 2max , vertical jump, and deadlift occurred. Squat and bench press improved (p = 0.01 and p = 0.02, respectively) with a decline in percent body fat (p = 0.03) and a trend for increased fat free mass (p = 0.09). Additionally, total cortisol (TCORT) negatively correlated with fat free mass (r = −0.48; p = 0.03) and positively correlated with VO 2max (r = 0.47; p = 0.04). A trend was shown for a positive correlation between both TCORT and free cortisol (FCORT) and percent body fat (r = 0.39; r = 0.40; p = 0.08, respectively). IGF-1 and growth hormone positively correlated to deadlift (r = 0.57; P = 0.02 and r = 0.59; p = 0.03), whereas creatine kinase showed a trend for a positive correlation with deadlift (r = 0.49; p = 0.06). IL-6 negatively correlated with bench press (r = −0.53; p = 0.03). McFadden et al. Biomarkers Correlate With Performance These findings support a relationship between biomarkers, performance outcomes, and body composition. Biomarker monitoring may be useful to detect individual player's physiological response to an athletic season and may help provide insights in efforts to optimize performance outcomes.

Adequate fluid replacement during exercise is an important consideration for athletes, however sweat rate (SR) can vary day-to-day. The purpose of this study was to investigate day-to-day variations in SR while performing self-selected exercise sessions to evaluate error in SR estimations in similar temperature conditions. Thirteen endurance-trained athletes completed training sessions in a case-series design 1x/week for a minimum 30 min of running/biking over 24 weeks. Body mass was recorded pre/post-training and corrected for fluid consumption. Data were split into three Wet-Bulb Globe Thermometer (WBGT) conditions: LOW (<10 °C), MOD (10–19.9 °C), HIGH (>20 °C). No significant differences existed in exercise duration, distance, pace, or WBGT for any group (p > 0.07). Significant differences in SR variability occurred for all groups, with average differences of: LOW = 0.15 L/h; MOD = 0.14 L/h; HIGH = 0.16 L/h (p < 0.05). There were no significant differences in mean SR between LOW-MOD (p > 0.9), but significant differences between LOW-HIGH and MOD-HIGH (p < 0.03). The assessment of SR can provide useful data for determining hydration strategies. The significant differences in SR within each temperature range indicates a single assessment may not accurately represent an individual’s typical SR even in similar environmental conditions.

No abstract

Background Antioxidant supplementation may provide protection against negative health consequences of oxygen-free radicals caused by aerobic and re-sustained exercise. The aim is to find out the efficacy of antioxidant rich nutrient bar supplementation on the antioxidant status and physical fitness components of athletes. Method Forty track and field athletes were selected using convenience sampling technique. The Human Research Ethics Committee of PSG College of Arts and Science, Coimbatore approved the study. Voluntary participation of the subjects was emphasized and a written consent was obtained from them in order to be included in the study. An interview schedule was formulated to collect general information such as name, age, gender, and academic qualifications, as well as information pertaining to the types of sporting activity, duration of the activity per day, number of years involved in the respective sports and level of participation (district/state/national). Nutrient bars each weighing 50gm were prepared with rolled oats, pumpkin seeds, dehydrated carrots, flax seeds, peanuts, almonds, honey and date syrup as ingredients. Each athlete was provided with two bars containing 110 mg of antioxidant. The prepared bars were analyzed for their total anti-oxidant content using DPPH method. The experimental group (n = 20) was supplemented with the formulated nutrient bars every day for a period of 3 months, and the control group (n = 20) with a placebo. Bio-chemical parameters namely GSH, GSH-px, SOD, vitamin C, serum LPO and physical fitness tests such as 12 minutes test, speed test, step test, push-ups test, vertical jump test and hexagon agility test were assessed at baseline and after 90 days. Statistical analysis was performed using SPSS (version 15). ResultsThe mean age was 18 ± 3.2 yrs. Sixty percent of the selected athletes were males and 40 % females. The main source of nutrition information was from coaches (56 %) and magazines (30 %). The athletes of the experimental group, when compared with the control group, showed a significant increase in serum levels from 37.42 ± 12.01 units/min/ml to 42.08 ± 13.16 units/min/ml of SOD (p = 0.000). LPO increased from 2.89 ± 0.82 μg/ml to 3.80 ± 1.37 μg/ml (p = 0.005), GSH increased from 209.76 ± 8.17 μg/ml to 244.58 ± 33.36 μg/ml (p = 0.000). The mean levels of vitamin C and GSH-px decreased minimally in the experimental group but significantly in the control group. Significant improvement in all six physical fitness tests namely 12 minutes test (from 1.44 ± 0.142 to 1.56 ± 0.134) , speed test (from 6.5940 ± 0.258 to 6.7435 ± 0.25) step test (from 68.65 ± 5.51 to 78.35 ± 4.004) push-ups (from 22.25 ± 3.97 to 29.70 ± 3.40), vertical jumps test (from 60.00 ± 5.620 to 63.75 ± 6.043) and hexagon agility tests (from 12.255 ± 0.42 to 12.400 ± 0.51) were observed in the experimental group). However in the control group, the improvements were significant only in the 12 minutes test, step test and speed test. Conclusion Supplementation of athletes with antioxidant-rich...

No abstract

No abstract

No abstract