Comparison of Physical Fitness Parameters for Starters vs. Nonstarters in an NCAA Division I Men's Lacrosse Team.

Sell, KM, Prendergast, JM, Ghigiarelli, JJ, Gonzalez, AM, Biscardi, LM, Jajtner, AR, and Rothstein, AS. Comparison of physical fitness parameters for starters vs. nonstarters in an NCAA Division I men's lacrosse team. J Strength Cond Res 32(11): 3160-3168, 2018-The purpose of this study was to present a fitness profile of Division I male lacrosse players and compare the fitness attributes across different positions and starting status. Forty-one Division I men's lacrosse players (19.6 ± 1.6 years, 82.5 ± 9.5 kg, 182.0 ± 5.4 cm) volunteered to participate in the study. Fitness attributes assessed included aerobic fitness (1.5-mile run), muscular strength (1 repetition maximum bench press, squat, and hang clean), grip strength (hand dynamometer), explosive power (vertical jump), agility (3-cone drill, pro-agility), body composition (7-site skinfold), and speed (20- and 40-yard sprint). All testing was conducted by a certified strength and conditioning coach and occurred at the conclusion of pre-season training. The only significant difference across positions was for body mass, whereby defensemen were significantly heavier than attacking players (p < 0.05). Starters were significantly faster on the 3-cone drill, 20- and 40-yard sprint, and jumped significantly higher on the vertical jump compared with nonstarters (p < 0.05). Attributes pertaining to anaerobic fitness (speed, agility, and explosive power) may be better predictors of starting status than aerobic fitness in men's NCAA Division I lacrosse players. This differs from previous research on men's club lacrosse players where a difference in aerobic fitness and body composition was shown between starters and nonstarters. The normative data presented in this study may assist strength and conditioning coaches in the development of sport-specific training programs and motivate athletes toward achieving sport-specific fitness goals by helping identify areas of weakness before the start of the season.

Post-resistance exercise ingestion of milk protein attenuates plasma TNFα and TNFr1 expression on monocyte subpopulations.

Attenuating TNFα/TNFr1 signaling in monocytes has been proposed as a means of mitigating inflammation. The purpose of this study was to examine the effects of a milk protein supplement on TNFα and monocyte TNFr1 expression. Ten resistance-trained men (24.7 ± 3.4 years; 90.1 ± 11.3 kg; 176.0 ± 4.9 cm) ingested supplement (SUPP) or placebo (PL) immediately post-exercise in a randomized, cross-over design. Blood samples were obtained at baseline (BL), immediately (IP), 30-min (30P), 1-h (1H), 2-h (2H), and 5-h (5H) post-exercise to assess plasma concentrations of myoglobin; tumor necrosis factor-alpha (TNFα); and expression of tumor necrosis factor receptor 1 (TNFr1) on classical, intermediate, and non-classical monocytes. Magnitude-based inferences were used to provide inferences on the true effects of SUPP compared to PL. Plasma TNFα concentrations were "likely attenuated" (91.6% likelihood effect) from BL to 30P in the SUPP group compared with PL (d = 0.87; mean effect: 2.3 ± 2.4 pg mL-1). TNFr1 expressions on classical (75.9% likelihood effect) and intermediate (93.0% likelihood effect) monocytes were "likely attenuated" from BL to 2H in the SUPP group compared with PL (d = 0.67; mean effect: 510 ± 670 RFU, and d = 1.05; mean effect: 2500 ± 2300 RFU, respectively). TNFr1 expression on non-classical monocytes was "likely attenuated" (77.6% likelihood effect) from BL to 1H in the SUPP group compared with PL (d = 0.69; mean effect: 330 ± 430 RFU). Ingestion of a milk protein supplement immediately post-exercise appears to attenuate both plasma TNFα concentrations and TNFr1 expression on monocyte subpopulations in resistance-trained men.

Impact of Polyphenol Supplementation on Acute and Chronic Response to Resistance Training.

Beyer, KS, Stout, JR, Fukuda, DH, Jajtner, AR, Townsend, JR, Church, DD, Wang, R, Riffe, JJ, Muddle, TWD, Herrlinger, KA, and Hoffman, JR. Impact of polyphenol supplementation on acute and chronic response to resistance training. J Strength Cond Res 31(11): 2945-2954, 2017-This study investigated the effect of a proprietary polyphenol blend (PPB) on acute and chronic adaptations to resistance exercise. Forty untrained men were assigned to control, PPB, or placebo. Participants in PPB or placebo groups completed a 4-week supplementation period (phase I), an acute high-volume exercise bout (phase II), and a 6-week resistance training program (phase III); whereas control completed only testing during phase II. Blood draws were completed during phases I and II. Maximal strength in squat, leg press, and leg extension were assessed before and after phase III. The exercise protocol during phase II consisted of squat, leg press, and leg extension exercises using 70% of the participant's strength. The resistance training program consisted of full-body exercises performed 3 d·wk. After phase I, PPB (1.56 ± 0.48 mM) had greater total antioxidant capacity than placebo (1.00 ± 0.90 mM). Changes in strength from phase III were similar between PPB and placebo. Polyphenol blend supplementation may be an effective strategy to increase antioxidant capacity without limiting strength gains from training.

Exercise-Induced Hormone Elevations Are Related to Muscle Growth.

Mangine, GT, Hoffman, JR, Gonzalez, AM, Townsend, JR, Wells, AJ, Jajtner, AR, Beyer, KS, Boone, CH, Wang, R, Miramonti, AA, LaMonica, MB, Fukuda, DH, Witta, EL, Ratamess, NA, and Stout, JR. Exercise-induced hormone elevations are related to muscle growth. J Strength Cond Res 31(1): 45-53, 2017-Partial least squares regression structural equation modeling (PLS-SEM) was used to examine relationships between the endocrine response to resistance exercise and muscle hypertrophy in resistance-trained men. Pretesting (PRE) measures of muscle size (thickness and cross-sectional area) of the vastus lateralis and rectus femoris were collected in 26 resistance-trained men. Participants were randomly selected to complete a high-volume (VOL, n = 13, 10-12RM, 1-minute rest) or high-intensity (INT, n = 13, 3-5RM, 3-minute rest) resistance training program. Blood samples were collected at baseline, immediately postexercise, 30-minute, and 60-minute postexercise during weeks 1 (week 1) and 8 (week 8) of training. The hormonal responses (testosterone, growth hormone [22 kD], insulin-like growth factor-1, cortisol, and insulin) to each training session were evaluated using area-under-the-curve (AUC) analyses. Relationships between muscle size (PRE), AUC values (week 1 + week 8) for each hormone, and muscle size (POST) were assessed using a consistent PLS-SEM algorithm and tested for statistical significance (p ≤ 0.05) using a 1,000 samples consistent bootstrapping analysis. Group-wise comparisons for each relationship were assessed through independent t-tests. The model explained 73.4% (p < 0.001) of variance in muscle size at POST. Significant pathways between testosterone and muscle size at PRE (p = 0.043) and muscle size at POST (p = 0.032) were observed. The ability to explain muscle size at POST improved when the model was analyzed by group (INT: R = 0.882; VOL: R = 0.987; p < 0.001). No group differences in modal quality were found. Exercise-induced testosterone elevations, independent of the training programs used in this study, seem to be related to muscle growth.

Intramuscular MAPK signaling following high volume and high intensity resistance exercise protocols in trained men.

PURPOSE: To examine the mitogen-activated protein kinase (MAPK) family of signaling proteins following typical high volume (HV) and high intensity (HI) lower body resistance exercise protocols in resistance-trained men. METHODS: Ten resistance-trained men (24.7 ± 3.4 year; 90.1 ± 11.3 kg; 176.0 ± 4.9 cm) performed each resistance exercise protocol in a random, counterbalanced order. The HV protocol utilized a load of 70 % 1-RM for sets of 10-12 repetitions with a 1-min rest period length between sets and exercises. The HI protocol utilized a load of 90 % 1-RM for sets of 3-5 repetitions with a 3-min rest period length between sets and exercises. Both protocols included six sets of barbell back squats and four sets of bilateral leg press, bilateral hamstring curls, bilateral leg extensions, and seated calf raises. Fine needle muscle biopsies of the vastus lateralis were completed at baseline (BL) and 1-h post exercise (1H). RESULTS: No significant differences over time were noted for phosphorylation of MEK1, ERK1/2, p38, MSK1, ATF2, p53, or c-Jun (p > 0.05). No significance between trial interactions was noted for phosphorylation of MAPK signaling proteins, including MEK1, ERK1/2, p38, JNK, MSK1, ATF2, STAT1, p53, c-Jun, or HSP27 (p > 0.05). However, significant time effects were observed for phosphorylation of JNK (p < 0.01), HSP27 (p < 0.01), and STAT1 (p = 0.03). Phosphorylation of JNK, HSP27, and STAT1 was significantly elevated from BL at 1H for both HV and HI. CONCLUSIONS: HV and HI lower body resistance exercise protocols appear to elicit similar MAPK activation in resistance-trained men.

Resistance training intensity and volume affect changes in rate of force development in resistance-trained men.

PURPOSE: To compare the effects of two different resistance training programs, high intensity (INT) and high volume (VOL), on changes in isometric force (FRC), rate of force development (RFD), and barbell velocity during dynamic strength testing. METHODS: Twenty-nine resistance-trained men were randomly assigned to either the INT (n = 15, 3-5 RM, 3-min rest interval) or VOL (n = 14, 10-12 RM, 1-min rest interval) training group for 8 weeks. All participants completed a 2-week preparatory phase prior to randomization. Measures of barbell velocity, FRC, and RFD were performed before (PRE) and following (POST) the 8-week training program. Barbell velocity was determined during one-repetition maximum (1RM) testing of the squat (SQ) and bench press (BP) exercises. The isometric mid-thigh pull was used to assess FRC and RFD at specific time bands ranging from 0 to 30, 50, 90, 100, 150, 200, and 250 ms. RESULTS: Analysis of covariance revealed significant (p < 0.05) group differences in peak FRC, FRC at 30-200 ms, and RFD at 50-90 ms. Significant (p < 0.05) changes in INT but not VOL in peak FRC (INT: 9.2 ± 13.8 %; VOL: -4.3 ± 10.2 %), FRC at 30-200 ms (INT: 12.5-15.8 %; VOL: -1.0 to -4.3 %), and RFD at 50 ms (INT: 78.0 ± 163 %; VOL: -4.1 ± 49.6 %) were observed. A trend (p = 0.052) was observed for RFD at 90 ms (INT: 58.5 ± 115 %; VOL: -3.5 ± 40.1 %). No group differences were observed for the observed changes in barbell velocity. CONCLUSIONS: Results indicate that INT is more advantageous than VOL for improving FRC and RFD, while changes in barbell velocity during dynamic strength testing are similarly improved by both protocols in resistance-trained men.

Resistance exercise increases intramuscular NF-κb signaling in untrained males.

PURPOSE: The NF-κB signaling pathway regulates multiple cellular processes following exercise stress. This study aims to examine the effects of an acute lower-body resistance exercise protocol and subsequent recovery on intramuscular NF-κB signaling. METHODS: Twenty-eight untrained males 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 exercises. Skeletal muscle microbiopsies were obtained from the vastus lateralis pre-exercise (PRE), 1-hour (1H), 5-hours (5H), and 48-hours (48H) post-resistance exercise. Multiplex signaling assay kits (EMD Millipore, Billerica, MA, USA) were used to quantify the total protein (TNFR1, c-Myc) or phosphorylation status of proteins belonging to the NF-κB signaling pathway (IKKa/b, IkBα, NF-κB) using multiplex protein assay. Repeated measures ANOVA analysis was used to determine the effects of the exercise bout on intramuscular signaling at each time point. Additionally, change scores were analyzed by magnitude based inferences to determine a mechanistic interpretation. RESULTS: Repeated measures ANOVA indicated a trend for a two-way interaction between the EX and CON Group (p = 0.064) for c-Myc post resistance exercise. Magnitude based inference analysis suggest a "Very Likely" increase in total c-Myc from PRE-5H and a "Likely" increase in IkBα phosphorylation from PRE-5H post-resistance exercise. CONCLUSION: Results indicated that c-Myc transcription factor is elevated following acute intense resistance exercise in untrained males. Future studies should examine the role that post-resistance exercise NF-κß signaling plays in c-Myc induction, ribosome biogenesis and skeletal muscle regeneration.

Changes in Plasma Aldosterone and Electrolytes Following High-Volume and High-Intensity Resistance Exercise Protocols in Trained Men.

Boone, CH, Hoffman, JR, Gonzalez, AM, Jajtner, AR, Townsend, JR, Baker, KM, Fukuda, DH, and Stout, JR. Changes in plasma aldosterone and electrolytes following high-volume and high-intensity resistance exercise protocols in trained men. J Strength Cond Res 30(7): 1917-1923, 2016-Program variables such as training intensity, volume, and rest interval length are known to elicit distinct hormonal, metabolic, and physical responses. However, little is known regarding resistance exercise (RE) program design and the fluid regulatory response. This investigation aimed to compare the plasma aldosterone (ALD), electrolyte, plasma volume (PV), and osmolality (Posm) responses following high-volume (HV; 4-6 × 10-12 reps, 70% 1 repetition maximum [1RM], 60-s rest) and high-intensity (HI; 6 × 3-5 reps, 90% 1RM, 180-second rest) RE protocols. Ten experienced, resistance-trained men (24.7 ± 3.4 years; 90.1 ± 11.3 kg; 176.0 ± 4.9 cm) performed each protocol in a random, counterbalanced order. Blood samples were obtained at baseline (BL), immediately (IP), 30 minutes (30P), and 1 hour (1H) postexercise. Significant trial × time interactions (p < 0.01) were observed in Posm, sodium (Na), and potassium (K), whereas a trend (p = 0.06) was observed for ALD. The PV shift from BL-30P was greater than BL-IP and BL-1H (p ≤ 0.05), but no significant between-trial differences were noted. Comparisons between RE protocols revealed significantly greater (p ≤ 0.05) elevations during HV vs. HI in Posm at IP, 30P, and 1H; and Na at IP and 30P. During HV, significant reductions (p ≤ 0.05) were noted in K at IP compared with HI. Area under the curve analysis indicates a trend (p = 0.07) toward a higher ALD response following HV compared with HI. Results of this study indicate that high-volume, moderate-intensity resistance exercise seems to augment the fluid regulatory response to a greater extent than low-volume, high-intensity training.

Short-Term Unilateral Resistance Training Results in Cross Education of Strength Without Changes in Muscle Size, Activation, or Endocrine Response.

Short-term unilateral resistance training results in cross education of strength without changes in muscle size, activation, or endocrine response. J Strength Cond Res 30(5): 1213-1223, 2016-The purpose of this study was to assess the cross education of strength and changes in the underlying mechanisms (muscle size, activation, and hormonal response) after a 4-week unilateral resistance training (URT) program. A group of 9 untrained men completed a 4-week URT program on the dominant leg (DOM), whereas cross education was measured in the nondominant leg (NON); and were compared with a control group (n = 8, CON). Unilateral isometric force (PKF), leg press (LP) and leg extension (LE) strength, muscle size (by ultrasonography) and activation (by electromyography) of the rectus femoris and vastus lateralis, and the hormonal response (testosterone, growth hormone, insulin, and insulin-like growth factor-1) were tested pretraining and posttraining. Group × time interactions were present for PKF, LP, LE, and muscle size in DOM and for LP in NON. In all interactions, the URT group improved significantly better than CON. There was a significant acute hormonal response to URT, but no chronic adaptation after the 4-week training program. Four weeks of URT resulted in an increase in strength and size of the trained musculature, and cross education of strength in the untrained musculature, which may occur without detectable changes in muscle size, activation, or the acute hormonal response.

Effects of l-Alanyl-l-Glutamine Ingestion on One-Hour Run Performance.

OBJECTIVE: To examine the efficacy of l-alanyl-l-glutamine ingestion with a commercially available sports drink compared to the sports drink only on time to exhaustion and physiological measures during prolonged endurance exercise. METHODS: Twelve endurance-trained men (23.5 ± 3.7 years; 175.5 ± 5.4 cm; 70.7 ± 7.6 kg) performed 4 trials, each consisting of a 1-hour treadmill run at 75% VO2peak followed by a run to exhaustion at 90% VO2peak. One trial consisted of no hydration (NHY), another required ingestion of only a sports drink (ED), and 2 trials required ingestion of a low dose (LD; 300 mg·500 ml(-1)) and high dose (HD) of l-alanyl-l-glutamine (1 g·500 ml(-1)) added to the sports drink. During the fluid ingestion trials, 250 ml was consumed every 15 minutes. Plasma glutamine, glucose, electrolytes, and osmolality were measured prior to the run (PRE) and at 30, 45, and 60 minutes. VO2, respiratory quotient (RQ), and heart rate (HR) were measured every 15 minutes. RESULTS: Time to exhaustion was significantly longer during the LD and HD trials compared to NHY. No differences were noted in time to exhaustion between ED and NHY. Plasma glutamine concentrations were significantly elevated at 45 minutes in LD and HD trials and remained elevated at 60 minutes during HD. Sodium concentrations increased from the beginning of exercise and remained stable for the duration of the 1-hour run. At 60 minutes, plasma sodium was significantly lower in all trials compared to NHY. CONCLUSIONS: Results indicated that ingestion of the alanine-glutamine dipeptide at either the low or high dose significantly improved time to exhaustion during high-intensity exercise compared to a no-hydration trial.

Comparison of the effects of electrical stimulation and cold-water immersion on muscle soreness after resistance exercise.

CONTEXT: Resistance training is a common form of exercise for competitive and recreational athletes. Enhancing recovery from resistance training may improve the muscle-remodeling processes, stimulating a faster return to peak performance. OBJECTIVE: To examine the effects of 2 different recovery modalities, neuromuscular electrical stimulation (NMES) and cold-water immersion (CWI), on performance and biochemical and ultrasonographic measures. PARTICIPANTS: Thirty resistance-trained men (23.1 ± 2.9 y, 175.2 ± 7.1 cm, 82.1 ± 8.4 kg) were randomly assigned to NMES, CWI, or control (CON). DESIGN AND SETTING: All participants completed a high-volume lower-body resistance-training workout on d 1 and returned to the human performance laboratory 24 (24H) and 48 h (48 H) postexercise for follow-up testing. MEASURES: Blood samples were obtained preexercise (PRE) and immediately (IP), 30 min (30 P), 24 h (24H), and 48 h (48 H) post. Subjects were examined for performance changes in the squat exercise (total repetitions and average power per repetition), biomarkers of inflammation, and changes in cross-sectional area and echo intensity (EI) of the rectus femoris (RF) and vastus lateralis muscles. RESULTS: No differences between groups were observed in the number of repetitions (P = .250; power: P = .663). Inferential-based analysis indicated that increases in C-reactive protein concentrations were likely increased by a greater magnitude after CWI compared with CON, while NMES possibly decreased more than CON from IP to 24H. Increases in interleukin-10 concentrations between IP and 30 P were likely greater in CWI than NMES but not different from CON. Inferential-based analysis of RF EI indicated a likely decrease for CWI between IP and 48 H. No other differences between groups were noted in any other muscle-architecture measures. CONCLUSIONS: Results indicated that CWI induced greater increases in pro- and anti-inflammatory markers, while decreasing RF EI, suggesting that CWI may be effective in enhancing short-term muscle recovery after high-volume bouts of resistance exercise.

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.

Vastus lateralis exhibits non-homogenous adaptation to resistance training.

INTRODUCTION: Variations in transverse point of measure on the vastus lateralis (VL) may significantly affect the relationship between structure and function. The purpose of this study was to compare changes in muscle architecture at 2 commonly used points of measure (VL0 and VL5). METHODS: Maximal strength (1-repetition maximum [1RM] barbell squat) and muscle architecture were assessed PRE and POST 15 weeks of periodized resistance training. VL0 was 50% of the straight line distance between the greater trochanter and lateral epicondyle of the femur. VL5 was 5cm medial to VL0. RESULTS: Increases in 1RM strength (3.7 ± 2.4 kg; P = 0.004) were observed. Changes in muscle thickness (MT) at VL5 were significantly greater than at VL0 (P = 0.006). Changes in strength correlated with changes in muscle architecture at VL0 only (MT: r = 0.561; fascicle length: r = 0.503). CONCLUSIONS: Changes in muscle architecture appear to occur in a non-homogeneous manner.

Mediators of monocyte migration in response to recovery modalities following resistance exercise.

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.

Speed, force, and power values produced from nonmotorized treadmill test are related to sprinting performance.

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: r = 0.75, standard error of the estimate (SEE) = 0.27 seconds; TM2: r = 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 (r = 0.23, SEE = 0.48 seconds) and mean vertical jump power (r = 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.

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.

Resistance exercise may improve spatial awareness and visual reaction in older adults.

Aerobic exercise has been shown to counteract age-related neurological decrements that are associated with cognitive and physical impairments. However, the effects of resistance exercise on cognition, reaction, and neurotrophins are largely unknown. We examined changes in spatial awareness, visual and motor reaction, and circulating brain-derived neurotrophic factor (BDNF) in response to a resistance exercise intervention in older adults (aged 70.6 ± 6.1 years). Spatial awareness was evaluated before and after training with a Neurotracker perceptual 3-dimensional object-tracking device. Peripheral, visual, motor, and physical reaction times were evaluated using a Dynavision visuomotor device. Circulating BDNF was assayed. Data were analyzed for clinical significance using magnitude-based inferences calculated from independent t-tests. Clinical interpretations of the analyses revealed that resistance exercise training was "likely beneficial" for improving spatial awareness and visual and physical reaction times. Each improved by 40.0, 14.6, and 14.0%, respectively. Circulating BDNF and motor reaction time displayed no apparent meaningful changes. Thus, resistance exercise training may be an effective means to preserve or improve spatial awareness and reaction with aging.

Do changes in muscle architecture affect post-activation potentiation?

The purpose of this randomized, cross-over design study was to examine the effect of three different muscle potentiation protocols on acute changes in muscle architecture and vertical jump performance. Eleven experienced, resistance trained men (25.2±3.6y) completed three potentiation squat protocols using moderate intensity (MI; 75%, 3 sets x 10 repetitions), high intensity (HI; 90%, 3 sets x 3 repetitions) and 100% (1RM; 1 set x 1repetition) of their 1RM. In addition, all participants completed a control session (CTL) in which no protocol was performed. During each testing session, muscle architecture and vertical jump testing were assessed at baseline (BL), 8min post (8P) and 20min post (20P) workout. Ultrasound measures included cross sectional area (CSA) and pennation angle (PANG) of both the rectus femoris (RF) and vastus lateralis (VL). Following each ultrasound measure, peak vertical jump power (PVJP) and mean (MVJP) power was assessed using an accelerometer. Magnitude based inferences were used to make comparisons between trials. The MI trial resulted in a likely greater increase from BL to 8P and 20P in RF-CSA and VL-CSA, while the HI trial resulted in a likely greater change from BL to 20P in both RF-CSA and VL-CSA. Meanwhile, changes in PVJP and MVJP for the MI trial was likely decreased at BL-8P and BL-20P, while the HI trial was shown to result in a likely or possible decrease compared to CTL at BL-8P and BL-20P, respectively. A likely negative relationship was observed between changes in VL-PANG and MVJP (r = -0.35; p , 0.018) at BL-8P, and between changes in PVJP and RF-CSA (r = -0.37; p , 0.014) at BL-20P. Results of this study were unable to demonstrate any potentiation response from the trials employed, however these protocols did result in acute muscle architectural changes. Key pointsThree squat protocols using moderate intensity (75% 1-RM; 3 sets x 10 repetitions), high intensity (90% 1-RM, 3 sets x 3 repetitions) and maximal intensity (100% 1RM; 1 set x 1repetition) were unable to potentiate jump height or jump power in experienced, resistance trained men.Experienced, resistance trained athletes who are not competitive may be limited in regards to potentiation due to a poor level of conditioning.Both the moderate and high intensity potentiation protocols stimulated acute changes in muscle architecture. Greater increases in the CSA of both the RF and VL muscles were noted.A different potentiation protocol may have elicited greater changes in muscle architecture.