Effects of time-release caffeine containing supplement on metabolic rate, glycerol concentration and performance.

This study compared caffeine pharmacokinetics, glycerol concentrations, metabolic rate, and performance measures following ingestion of a time-release caffeine containing supplement (TR-CAF) versus a regular caffeine capsule (CAF) and a placebo (PL). Following a double-blind, placebo-controlled, randomized, cross-over design, ten males (25.9 ± 3.2 y) who regularly consume caffeine ingested capsules containing either TR-CAF, CAF, or PL. Blood draws and performance measures occurred at every hour over an 8-hour period. Plasma caffeine concentrations were significantly greater (p < 0.05) in CAF compared to TR-CAF during hours 2-5 and significantly greater (p = 0.042) in TR-CAF compared to CAF at hour 8. There were no significant differences between trials in glycerol concentrations (p = 0.86) or metabolic measures (p = 0.17-0.91). Physical reaction time was significantly improved for CAF at hour 5 (p=0.01) compared to PL. Average upper body reaction time was significantly improved for CAF and TR-CAF during hours 1-4 (p = 0.04 and p = 0.01, respectively) and over the 8-hour period (p = 0.04 and p = 0.001, respectively) compared to PL. Average upper body reaction time was also significantly improved for TR-CAF compared to PL during hours 5-8 (p = 0.004). TR-CAF and CAF showed distinct pharmacokinetics yielding modest effects on reaction time, yet did not alter glycerol concentration, metabolic measures, or other performance measures. Key pointsTime-release caffeine and regular caffeine showed distinct pharmacokinetics over an 8-hour period following ingestion.Time-release caffeine and regular caffeine yielded modest effects on reaction time over an 8-hour period following ingestion.Time-release caffeine and regular caffeine did not alter glycerol concentration, metabolic measures, or other performance measures over an 8-hour period following ingestion.

Effects of ß-hydroxy-ß-methylbutyrate free acid and cold water immersion on expression of CR3 and MIP-1ß following resistance exercise.

The inflammatory response to muscle-damaging exercise requires monocyte mobilization and adhesion. Complement receptor type 3 (CR3) and macrophage inflammatory protein (MIP)-1ß enables monocyte recruitment, adhesion, and subsequent infiltration into damaged muscle tissue. The purpose of this study was to examine the effects of cold water immersion (CWI) and/or ß-hydroxy-ß-methylbutyrate free acid (HMB-FA) on CR3 expression and MIP-1ß concentration after four sets of up to 10 repetitions of squat, dead lift, and split squat exercises at 70-80% 1-repetition maximum. Thirty-nine resistance-trained men (22.2 ± 2.5 yr) were randomly divided into four groups: 1) placebo (PL), 2) HMB-FA, 3) HMB-FA-CWI, and 4) PL-CWI. The HMB-FA groups ingested 3 g/day, and CWI groups were submersed into 10-12°C water for 10 min after exercise. Blood was sampled at baseline (PRE), immediately post- (IP), 30 min post- (30P), 24 h post- (24P), and 48 h post (48P)-exercise. Circulating MIP-1ß was assayed and CR3 expression on CD14+ monocytes was measured by flow cytometry. Without treatment, CR3 expression significantly elevated at 30P compared with other time points (P = 0.030-0.047). HMB-FA significantly elevated the percentage of monocytes expressing CR3 between IP and 24P (P = 0.046) and between IP and 48P (P = 0.046). No time effect was observed for MIP-1ß concentration. The recovery modalities showed to attenuate the rise in CR3 following exercise. Additionally, supplementation with HMB-FA significantly elevated the percentage of monocytes expressing CR3 during recovery. Although the time course that inflammatory responses are most beneficial remains to be determined, recovery modalities may alter immune cell mobilization and adhesion mechanisms during tissue recovery.

Effects of ß-hydroxy-ß-methylbutyrate free acid and cold water immersion on post-exercise markers of muscle damage.

The aim of the current study was to examine the effects of cold water immersion (CWI) with and without the free acid form of ß-hydroxy-ß-methylbutyrate (HMB-FA) on markers of muscle damage following acute lower body resistance exercise. Forty recreationally resistance-trained men (22.3 ± 2.4 years) were randomly divided into one of the four groups: (1) Placebo (PL); (2) HMB-FA; (3) HMB-FA-CWI; (4) PL-CWI. HMB-FA groups ingested 3 g day(-1) and CWI groups submersed their lower body into 10-12 °C water for 10-min post-exercise. No differences between groups were observed for CK; however, PL-CWI had significantly greater elevations in myoglobin 30-min post-exercise compared to HMB-FA (p = 0.009) and PL (p = 0.005), and HMB-FA-CWI was significantly greater than HMB-FA (p = 0.046) and PL (p = 0.028). No differences between groups were observed for IL-6 and IL-10, although CRP was significantly greater 24-h post-exercise for PL-CWI compared to HMB-FA-CWI (p = 0.02) and HMB-FA (p = 0.046). Only HMB-FA-CWI showed significantly (p = 0.02) greater improvements in average power per repetition. CWI appeared to elevate myoglobin compared to other groups, while HMB-FA may have attenuated the increase in CRP when combined with CWI. Nevertheless, HMB-FA or CWI treatments did not appear to provide benefit over PL for recovery. Instead, the combination of CWI and HMB-FA improved performance recovery compared to other groups.

Resistance training improves single leg stance performance in older adults.

Age-associated losses in muscle mass, or sarcopenia, are marked by accompanying decrements in strength and muscle quality, impairing balance and increasing the risk for falls. Although progressive resistance training has been widely accepted as an appropriate modality for the treatment of sarcopenia, it has yet to offer consistent results in terms of improved balance. The purpose of the present research was to investigate the effects on static balance performance following a 6-week full-body progressive resistance training program in untrained older adults. Evaluation of magnitude-based inferences indicated the progressive resistance training intervention to be likely beneficial for improving static balance performance. These results were likely related to the strengthening of all major muscle groups by the incorporation of both free weights and resistance machines in the exercise regimen. Our findings support the use of progressive resistance training for untrained older adults to improve balance.

Visual tracking speed is related to basketball-specific measures of performance in NBA players.

The purpose of this study was to determine the relationship between visual tracking speed (VTS) and reaction time (RT) on basketball-specific measures of performance. Twelve professional basketball players were tested before the 2012-13 season. Visual tracking speed was obtained from 1 core session (20 trials) of the multiple object tracking test, whereas RT was measured by fixed- and variable-region choice reaction tests, using a light-based testing device. Performance in VTS and RT was compared with basketball-specific measures of performance (assists [AST]; turnovers [TO]; assist-to-turnover ratio [AST/TO]; steals [STL]) during the regular basketball season. All performance measures were reported per 100 minutes played. Performance differences between backcourt (guards; n = 5) and frontcourt (forward/centers; n = 7) positions were also examined. Relationships were most likely present between VTS and AST (r = 0.78; p < 0.003), STL (r = 0.77; p < 0.003), and AST/TO (r = 0.78; p < 0.003), whereas a likely relationship was also observed with TO (r = 0.49; p < 0.109). Reaction time was not related to any of the basketball-specific performance measures. Backcourt players were most likely to outperform frontcourt players in AST and very likely to do so for VTS, TO, and AST/TO. In conclusion, VTS seems to be related to a basketball player's ability to see and respond to various stimuli on the basketball court that results in more positive plays as reflected by greater number of AST and STL and lower turnovers.

Performance and muscle architecture comparisons between starters and nonstarters in National Collegiate Athletic Association Division I women's soccer.

This study compared performance and muscle architecture (MA) changes in starters (S) and nonstarters (NS) during a National Collegiate Athletic Association Division I women's soccer season. Twenty-eight women (19.9 ± 1.1 years; 1.71 ± 0.08 m; 64.7 ± 6.4 kg) were monitored for vertical jump power (VJP), repeated line drills (LDs), 3-dimensional multiple object tracking (3D-MOT), and reaction time (RT) at preseason, midseason, and postseason. Muscle architecture changes using ultrasonography were assessed at preseason and postseason. Comparisons between S (n = 11; 70.0 ± 14.6 min per game) and NS (n = 17; 8.4 ± 8.0 min per game) were performed to make magnitude-based inferences. No differences were seen in VJP during the season in either group. Starters were more likely (81.1%) to decrease LD time than NS, with no differences in fatigue rate. Starters and NS improved 3D-MOT (1.14 ± 0.41 to 1.55 ± 0.43) and RT (0.37 ± 0.05 to 0.34 ± 0.33 seconds), with no differences between groups. Rectus femoris (RF) echo intensity improved (65.57 ± 1.50 to 61.26 ± 1.59) in both groups, with no interactions observed. Cross-sectional area (20.84 ± 3.58 to 21.46 ± 3.66 cm) increased and pennation angle (PANG) (12.58 ± 2.56 to 11.78 ± 2.03°) decreased for both groups in the vastus lateralis (VL). Muscle architecture comparisons between groups revealed S likely decreased VL muscle thickness (MT) and PANG (81.6 and 79.4%, respectively) and possibly decreased RF MT and PANG (65.7 and 59.4%, respectively) when compared with NS. Results indicate that VJP and LD fatigue rate are not changed during a competitive season, but S become faster than NS. Three-dimensional multiple object tracking and RT improve regardless of playing time. Changes in MA indicate that practices alone provide sufficient stimulus for improving muscle quality during the competitive season.

Effect of acute L-Alanyl-L-Glutamine and electrolyte ingestion on cognitive function and reaction time following endurance exercise.

The purpose of this study was to examine the effect of the L-Alanyl-L-Glutamine dipeptide (AG) on cognitive function and reaction time (RT) following endurance exercise. Twelve male endurance athletes (23.5 ± 3.7 y; 175.5 ± 5.4 cm; 70.7 ± 7.6 kg) performed four trials, each consisting of running on a treadmill at 70% of VO2max for 1h, then at 90% of VO2max until exhaustion. One trial consisted of no hydration (DHY), another required ingestion of only a sports electrolyte drink (ED) and two trials required ingestion of a low dose (LD; 300 mg·500 ml(-1)) and high dose (HD) of AG (1 g·500ml(-1)) added to the ED. Cognitive function and reaction tests were administered pre- and post-exercise. Magnitude based inferences were used to analyze ∆ cognitive function and ∆ reaction test data. Results indicated that DHY had a possible negative effect on number of hits in a 60-sec reaction test compared to LD and HD, while ED appeared to have a negative effect compared to HD. Analysis of lower body quickness indicated that LD and HD were likely improved in comparison to DHY. Performance on the serial subtraction test appeared to be possibly better in ED than DHY, while other comparisons between groups regarding cognitive function were unclear. In conclusion, rehydrating with AG during submaximal exercise may maintain or enhance subsequent RT in upper and lower body activities compared to DHY. These same effects were not apparent when participants consumed ED.

Moderate Altitude Affects High Intensity Running Performance in a Collegiate Women's Soccer Game.

The effect of altitude on soccer game activity profiles was retrospectively examined in six NCAA Division I female soccer players. Comparisons were made between two matches played at sea level (SL) and one match played at a moderate altitude (1839 m). A 10-Hz global positioning system device was used to measure distance and velocity. The rate of total distance capacity (TDC) and high intensity running (HIR) as well as percent of time at HIR were evaluated. Significant differences were seen in the distance rate (120.55 ± 8.26 m·min-1 versus 105.77 ± 10.19 m·min-1) and the HIR rate (27.65 ± 9.25 m·min-1 versus 25.07 ± 7.66 m·min-1) between SL and altitude, respectively. The percent of time at HIR was not significantly different (p = 0.064), yet tended to be greater at SL (10.4 ± 3.3%) than at altitude (9.1 ± 2.2%). Results indicate that teams residing at SL and competing at a moderate altitude may have a reduced ability in distance covered and a high intensity run rate.

Sprinting performance on the Woodway Curve 3.0 is related to muscle architecture.

To determine if unilateral measures of muscle architecture in the rectus femoris (RF) and vastus lateralis (VL) were related to (and predictive of) sprinting speed and unilateral (and bilateral) force (FRC) and power (POW) during a 30 s maximal sprint on the Woodway Curve 3.0 non-motorized treadmill. Twenty-eight healthy, physically active men (n = 14) and women (n = 14) (age = 22.9 ± 2.4 years; body mass = 77.1 ± 16.2 kg; height = 171.6 ± 11.2 cm; body-fa t = 19.4 ± 8.1%) completed one familiarization and one 30-s maximal sprint on the TM to obtain maximal sprinting speed, POW and FRC. Muscle thickness (MT), cross-sectional area (CSA) and echo intensity (ECHO) of the RF and VL in the dominant (DOM; determined by unilateral sprinting power) and non-dominant (ND) legs were measured via ultrasound. Pearson correlations indicated several significant (p < 0.05) relationships between sprinting performance [POW (peak, DOM and ND), FRC (peak, DOM, ND) and sprinting time] and muscle architecture. Stepwise regression indicated that POW(DOM) was predictive of ipsilateral RF (MT and CSA) and VL (CSA and ECHO), while POW(ND) was predictive of ipsilateral RF (MT and CSA) and VL (CSA); sprinting power/force asymmetry was not predictive of architecture asymmetry. Sprinting time was best predicted by peak power and peak force, though muscle quality (ECHO) and the bilateral percent difference in VL (CSA) were strong architectural predictors. Muscle architecture is related to (and predictive of) TM sprinting performance, while unilateral POW is predictive of ipsilateral architecture. However, the extent to which architecture and other factors (i.e. neuromuscular control and sprinting technique) affect TM performance remains unknown.

Reduced high-intensity-running rate in collegiate women's soccer when games are separated by 42 hours.

PURPOSE: During the competitive soccer season, women's intercollegiate matches are typically played on Friday evenings and Sunday afternoons. The efficacy of a 42-h recovery period is not well understood. This investigation was conducted to determine performance differences between Friday and Sunday matches during a competitive season. METHODS: Ten NCAA Division I female soccer players (20.5±1.0 y, 166.6±5.1 cm, 61.1±5.8 kg) were monitored with 10-Hz GPS devices across 8 weekends with matches played on Friday evenings and Sunday afternoons. The players were outside backs, midfielders, and forwards. All players had to participate in a minimum of 45 min/match to be included in the study. Average minutes played, total distance covered, total distance of high-intensity running (HIR) (defined as running at a velocity equal to or exceeding 3.61 m/s for longer than 1 s), the number of HIR efforts, and the number of sprints were calculated for each match. Data for Friday vs Sunday matches were averaged and then compared using dependent t tests. RESULTS: No differences were seen in minutes played, distance rate, or number of sprints between Friday and Sunday matches. A significant (P=.017) decrease in rate of HIR between Friday (25.37±7.22 m/min) and Sunday matches (22.90±5.70 m/min) was seen. In addition, there was a trend toward a difference (P=.073) in the number of efforts of HIR between Friday (138.41±36.43) and Sunday (126.92±31.31). CONCLUSIONS: NCAA Division I female soccer players cover less distance of HIR in games played less than 48 h after another game. This could be due to various factors such as dehydration, glycogen depletion, or muscle damage.

ß-Hydroxy-ß-methylbutyrate (HMB)-free acid attenuates circulating TNF-α and TNFR1 expression postresistance exercise.

The purpose of this study was to examine the effect of ß-hydroxy-ß-methylbutyrate-free acid (HMB-FA) and cold-water immersion (CWI) on circulating concentrations of TNF-α and monocyte TNF-α receptor 1 (TNFR1) expression. Forty resistance-trained men (22.3 ± 2.4 yr) were randomized into four groups [placebo (PL), HMB-FA, CWI, and HMB-FA-CWI] and performed an acute, intense exercise protocol (four sets of up to 10 repetitions of the squat, dead lift, and split squat). Participants also performed four sets of up to 10 repetitions of the squat at 24 and 48 h following the initial exercise bout. Blood was sampled before exercise (PRE), immediately postexercise (IP), and 30 min, 24 h, and 48 h postexercise (30P, 24P, and 48P, respectively). Circulating TNF-α was assayed, and TNFR1 expression on CD14+ monocytes was measured by flow cytometry. The exercise protocol significantly elevated TNF-α in only PL (P = 0.006) and CWI (P = 0.045) IP. Mean percent changes show that TNF-α significantly increased from PRE to IP for only PL and CWI groups (P < 0.05), whereas the percent change of TNF-α for HMB-FA and HMB-FA-CWI was not significant. TNFR1 expression was elevated in PL (P = 0.023) and CWI (P = 0.02) at 30P compared with PRE, whereas both HMB-FA-treated groups did not increase significantly. In conclusion, HMB-FA attenuated circulating TNF-α IP and TNFR1 expression during recovery compared with PL and CWI. HMB-FA supplementation may attenuate the initial immune response to intense exercise, which may reduce recovery time following intense exercise.