Mediators of monocyte migration, complement receptor-3 (CR3), and chemokine ligand-4 (CCL4) were measured in response to recovery modalities following resistance exercise. Thirty resistance-trained men (23.1±2.9 y;175.2±7.1 cm;82.1±8.4 kg) were given neuromuscular electric stimulation (NMES), cold water immersion (CWI), or control (CON) treatments immediately following resistance exercise. Blood samples were obtained preexercise (PRE), immediately (IP), 30 minutes (30 P), 24 hours (24 H), and 48 hours (48 H) after exercise for measurement of circulating CCL4 and CR3 expression on CD14+ monocytes, by assay and flow cytometry. Circulating CCL4 showed no consistent changes. Inferential analysis indicated that CR3 expression was likely greater in CON at 30 P than NMES (90.0%) or CWI (86.8%). NMES was likely lower than CON at 24 H (92.9%) and very likely lower at 48 H (98.7%). Expression of CR3 following CWI was very likely greater than CON (96.5%) at 24 H. The proportion of CR3+ monocytes was likely greater following CWI than NMES (85.8%) or CON (85.2%) at 24 H. The change in proportion of CR3+ monocytes was likely (86.4%) greater following NMES than CON from IP to 30 P. The increased expression of CR3 and increased proportion of CR3+ monocytes following CWI at 24 H indicate a potentially improved ability for monocyte adhesion to the endothelium, possibly improving phagocytosis of damaged tissues.
Mangine, GT, Hoffman, JR, Wells, AJ, Gonzalez, AM, Rogowski, JP, Townsend, JR, Jajtner, AR, Beyer, KS, Bohner, JD, Pruna, GJ, Fragala, MS, and Stout, JR. Visual tracking speed is related to basketball-specific measures of performance in NBA players. J Strength Cond Res 28(9): 2406–2414, 2014—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.
Apoptosis, or programmed cell death, is an essential physiological process regulating cellular development and is often associated with advanced stages of inflammation and disease. However, limited research has focused on skeletal muscle apoptosis as result of exercise induced muscular trauma. PURPOSE: To observe the effects of an acute lower-body resistance exercise protocol and subsequent recovery on intramuscular apoptotic signaling. METHODS: Twenty-eight untrained males (22.3 ± 3.2 y, 1.7 ± 0.1 m, 81.1 ± 15.5 kg) were assigned to either a control (CON; n=11) or exercise group (EX; n=17) and completed a lower-body resistance exercise protocol consisting of the back squat, leg press, and leg extension exercise. Skeletal muscle microbiopsies were obtained from the vastus lateralis pre-exercise (PRE), 1-hour (1HR), 5-hour (5HR), and 48-hours (48HR) post-resistance exercise. Multiplex signaling assay kits (EMD Millipore, Billerica, MA, USA) were used to quantify the total protein (Caspase-3,-8,-9) or phosphorylation status of proteins (JNK, FADD, p53, BAD, Bcl-2) specific to apoptotic signaling pathways using MAGPIX® (Luminex, Austin, TX, USA). Mann Whitney U analysis was used to determine the effects of the exercise bout on intramuscular signaling. Additionally, change scores were analyzed by magnitude based inferences to determine a mechanistic interpretation. RESULTS: Mann-Whitney U analysis revealed that resistance exercise increased JNK phosphorylation at 1H (p=0.001) and 5H (p=0.022), and FADD phosphorylation at 1H (p=0.029). No other differences observed between groups. Magnitude based inferences revealed a “Likely” increase in total Caspase 3 from PRE-5H and from PRE-48H. JNK phosphorylation was “Most Likely” increased from PRE-1H and PRE-5H and FADD was “Likely” increased from PRE-1H. BAD was “Very Likely” increased from PRE-5H and Bcl-2 was “Most Likely” increased from PRE-1H and “Likely” increased” from PRE-5H. CONCLUSION: These data show that apoptotic signaling is upregulated in response to a typical resistance exercise protocol, providing additional insight into the physiological mechanisms involved in skeletal muscle remodeling following resistance exercise.
This study compared caffeine pharmacokinetics, glycerol concentrations, metabolic rate, and performance measures following ingestion of a time-release caffeine containing supplement (TRCAF) 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.
Proteases are enzymes which aid in the hydrolysis of proteins. Previous work has demonstrated protease supplementation may enhance recovery after high-intensity exercise by decreasing muscle damage and inflammation. While the mechanisms involved are not fully understood, it has been suggested that protease supplementation may alter the endocrine response to exercise, promoting a more favorable recovery state. PURPOSE: To determine if protease supplementation immediately after an exercise session influences circulating testosterone, cortisol, insulin, insulin-like growth factor-1 (IGF-1), and growth hormone (GH) concentrations. METHODS: Ten resistance trained males (24.1±4.1yr, 69.6±6.8 kg 179±8.6 cm) completed 3 acute lower-body resistance exercise sessions consisting of 4 sets of leg press and leg extension in a randomized, crossover fashion. Each exercise was performed at 75% of participant’s previously determined one repetition maximum, for 8-10 repetitions, with 90 seconds of rest between sets. Following the exercise session, participants consumed one of 3 treatments (W: 26g whey; PW: 26g whey + 250mg of a protease enzyme blend; PL: non-caloric control). Blood draws were obtained at baseline (BL), immediately-post (IP), 1-hour (1H) and 3-hours post-exercise (3H) and analyzed for testosterone, cortisol, insulin, IGF-1, and GH. Data for each hormone were analyzed with a 2-way repeated measures analysis of variance (ANOVA), while area under the curve (AUC) values were analyzed with a one-way ANOVA. RESULTS: Significant main effects for time (p<0.05) were observed for all hormones. There was a significant decrease in testosterone at IP (p=0.007), 1H (p<0.001), and 3H (p<0.001). There was a significant decrease in cortisol at all time points (p<0.001) compared to BL. There were significant increases in insulin, IGF-1, and growth hormone at all time points (p<0.001) following exercise. Additionally, no interaction for any hormone concentrations or AUC values were seen between treatments in this study. CONCLUSION: There were no differential effects of W or PW on the post-exercise endocrine response compared to PL. Therefore, neither protease nor protein supplementation appear to alter endocrine response to resistance exercise in trained males. Supported by Deerland Enzymes, Kennesaw, GA
Background: Brain-derived neurotrophic factor (BDNF) has been demonstrated to have an important role in neuronal remodeling and modulating synaptic plasticity and neurotransmitter release. Acute elevations in BDNF concentrations have been seen during exercise, the understanding in resistance trained (RT) men, and the difference between high intensity (HI) and high volume (HV) protocols is limited. PURPOSE: To examine the response of BDNF to acute bouts of HI and HV in experienced, RT men. METHODS: Twenty experienced resistance trained men (23.5 ± 2.6 y, 1.79 ± 0.05 m, 75.7 ± 13.75) volunteered for this study. To ensure participants were trained, 10 weeks of supervised training occurred prior to the acute bout. The first 2-weeks was a preparatory phase, after which participants were randomized into either a HV (n = 10, 4 x 10-12RM, 1-min rest) or HI (n = 10, 4 x 3-5RM, 3-min rest) training protocol. Participants trained for an additional 8 weeks (4 d·week-1). During the acute training session resting blood draws were obtained prior to (PRE), immediately (IP), 30 min (30P), and 60 min (60P) post-exercise. Plasma BDNF concentrations were determined using a multiplex signaling assay kit and analyzed with MAGPIX® technology. Data were analyzed using a group x time repeated measures ANOVA. Additionally, area under curve (AUC) was calculated and analyzed with an independent t-test. RESULTS: The repeated measures ANOVA demonstrated a significant (p=0.019) main effect for time. BDNF concentrations were significantly elevated from PRE (1911.63 ± 447.79 pg·ml-1) at 30P (3579.47 ± 680.04 pg·ml-1), and 60P (3307.75 ± 536.80 pg·ml-1). In addition, BDNF concentrations were significantly greater at 30P than IP (2624.37 ± 399.67 pg·ml-1). When collapsed across time, the BDNF response during HV (3572.92 ± 545.33 pg·ml-1) tended to be higher (p = 0.079) than during HI (2138.69 ± 545.33 pg·ml-1). However, no significant interactions (p=0.325), or differences for AUC (p=0.257) were observed. CONCLUSIONS: The results of this study indicate BDNF increases in response to a resistance training stress in resistance trained men. However, comparisons between HV and HI training indicates a trend towards a difference in the BDNF response.
Mangine, GT, Hoffman, JR, Gonzalez, AM, Wells, AJ, Townsend, JR, Jajtner, AR, McCormack, WP, Robinson, EH, Fragala, MS, Fukuda, DH, and Stout, JR. Speed, force, and power values produced from nonmotorized treadmill test are related to sprinting performance. J Strength Cond Res 28(7): 1812–1819, 2014—The relationships between 30-m sprint time and performance on a nonmotorized treadmill (TM) test and a vertical jump test were determined in this investigation. Seventy-eight physically active men and women (22.9 ± 2.7 years; 73.0 ± 14.7 kg; 170.7 ± 10.4 cm) performed a 30-second maximal sprint on the curve nonmotorized TM after 1 familiarization trial. Pearson product-moment correlation coefficients produced significant (p ≤ 0.05) moderate to very strong relationships between 30-m sprint time and body mass (r = −0.37), %fat (r = 0.79), peak power (PP) (r = −0.59), relative PP (r = −0.42), time to peak velocity (r = −0.23) and TM sprint times at 10 m (r = 0.48), 20 m (r = 0.59), 30 m (r = 0.67), 40 m (r = 0.71), and 50 m (r = 0.75). Strong relationships between 30-m sprint time and peak (r = −0.479) and mean vertical jump power (r = −0.559) were also observed. Subsequently, stepwise regression was used to produce two 30-m sprint time prediction models from TM performance (TM1: body mass + TM data and TM2: body composition + TM data) in a validation group (n = 39), and then crossvalidated against another group (n = 39). As no significant differences were observed between these groups, data were combined (n = 72) and used to create the final prediction models (TM1: r2 = 0.75, standard error of the estimate (SEE) = 0.27 seconds; TM2: r2 = 0.84, SEE = 0.22 seconds). These final movement-specific models seem to be more accurate in predicting 30-m sprint time than derived peak (r2 = 0.23, SEE = 0.48 seconds) and mean vertical jump power (r2 = 0.31, SEE = 0.45 seconds) equations. Consequently, sprinting performance on the TM can significantly predict short-distance sprint time. It, therefore, may be used to obtain movement-specific measures of sprinting force, velocity, and power in a controlled environment from a single 30-second maximal sprinting test.
β-hydroxy-β-methylbutyrate (HMB) is a metabolite of leucine, a branched chained amino acid which functions as an effective stimulator of muscle protein synthesis. This chapter explores the proposed mechanisms of action for HMB raging from its effect on intramuscular signalling to its immunomodulatory properties. It aims to compare common formulations of the compound along with effective dosing strategies. The chapter discusses the effects of acute supplementation with HMB and its influence on markers of muscle damage, immune cells, physical function and recovery from strenuous muscular exertion. While HMB has gained popularity primarily in the athletic realm, it reviews its efficacy in relation the clinical populations such as those with sarcopenia, cachexia and other chronic conditions. In addition to an ability to enhance myofibrillar protein synthesis rates, HMB appears to exert its most prominent effects by reducing catabolism from muscle protein breakdown. The chapter concludes with a discussion of the safety and legality of HMB for various populations and application in sport.
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.
