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.

Homogeneity of echo intensity values in transverse ultrasound images.

INTRODUCTION: Echo intensity of skeletal muscle measured by means of ultrasonography has been used to assess muscle quality, however, the heterogeneity of echo intensity has not been thoroughly investigated. Therefore, this study examined echo intensity in different sections of panoramic ultrasound images captured in the transverse plane. METHODS: Echo intensity of the vastus lateralis was assessed in 24 men (20.2 ± 1.6 years) using panoramic ultrasonography. Echo intensity homogeneity was examined by dividing each image into 3 compartments of equal horizontal length (tertiles). RESULTS: No differences were found between echo intensity of the anterior tertile (59.1 ± 9.1 AU), posterior tertile (56.4 ± 9.9 AU), lateral tertile (58.7 ± 9.9 AU), or the overall panoramic image (58.0 ± 8.8 AU). CONCLUSIONS: Echo intensity of the vastus lateralis appears to be homogeneous as assessed in the transverse plane. Further research is necessary to determine if still imaging is sufficient to obtain an accurate measure of echo intensity. Muscle Nerve 56: 93-98, 2017.

Scanning plane comparison of ultrasound-derived morphological characteristics of the vastus lateralis.

Muscle morphological characteristics obtained via ultrasonography have been used to quantify the size, architecture, and quality of skeletal muscle. Previous research has utilized varying ultrasonographic techniques, however there is little information comparing these different techniques. Muscle morphological characteristics, including cross-sectional area (CSA), muscle thickness (MT), echo intensity (EI), and subcutaneous adipose tissue thickness (SubQ) were assessed in 24 males (20.2 ± 1.6 y) via three panoramic-images captured in the transverse plane (PTI) and three still-images captured in the longitudinal plane (SLI). Cross-sectional area of PTI was significantly greater than CSA of SLI (P < 0.001), however positive correlations existed between the two measurements (r = 0.752, P < 0.001). Echo intensity of PTI was significantly lower than EI of SLI (P = 0.002), however, positive correlations existed between the two measurements (r = 0.681, P < 0.001). MT of PTI was significantly greater than MT of SLI (P = 0.003), but positive correlations existed between measurements (r = 0.809, P < 0.001). However, SubQ of PTI was significantly lower than SubQ of SLI (P < 0.001), but positive correlations existed between measurements (r = 0.915, P < 0.001). In conclusions, PTI and SLI yield significantly different CSA, EI, MT, and SubQ measurements but these values are highly correlated. Still longitudinal images require less time, cost, and expertise, and therefore may be preferred over PTI in future studies. Clin. Anat. 30:533-542, 2017. © 2016 Wiley Periodicals, Inc.

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.

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.

Physical Differences Between Forwards and Backs in American Collegiate Rugby Players.

La Monica, MB, Fukuda, DH, Miramonti, AA, Beyer, KS, Hoffman, MW, Boone, CH, Tanigawa, S, Wang, R, Church, DD, Stout, JR, and Hoffman, JR. Physical differences between forwards and backs in American collegiate rugby players. J Strength Cond Res 30(9): 2382-2391, 2016-This study examined the anthropometric and physical performance differences between forwards and backs in a championship-level American male collegiate rugby team. Twenty-five male rugby athletes (mean ± SD; age 20.2 ± 1.6 years) were assessed. Athletes were grouped according to position as forwards (n = 13) and backs (n = 12) and were evaluated on the basis of anthropometrics (height, weight, percent body fat [BF%]), cross-sectional area (CSA), muscle thickness (MT), and pennation angle (PA) of the vastus lateralis (VL), maximal strength (1 repetition maximum [1RM] bench press and squat), vertical jump power, midthigh pull (peak force [PF] and peak rate of force development [PRFD]), maximal aerobic capacity (V[Combining Dot Above]O2peak), agility (pro agility, T test), speed (40-m sprint), and a tethered sprint (peak velocity [PV], time to peak velocity, distance covered, and step rate and length). Comparisons between forwards and backs were analyzed using independent t-tests with Cohen's d effect size. Forwards were significantly different from backs for body weight (90.5 ± 12.4 vs. 73.7 ± 7.1 kg, p < 0.01; d = 1.60), BF% (12.6 ± 4.2 vs. 8.8 ± 2.1%, p ≤ 0.05; d = 1.10), VL CSA (38.3 ± 9.1 vs. 28.7 ± 4.7 cm, p < 0.01; d = 1.26), 1RM bench press (121.1 ± 30.3 vs. 89.5 ± 20.4 kg, p ≤ 0.05; d = 1.17), 1RM squat (164.6 ± 43.0 vs. 108.5 ± 31.5 kg, p < 0.01; d = 1.42), PF (2,244.6 ± 505.2 vs. 1,654.6 ± 338.8 N, p < 0.01; d = 1.32), PV (5.49 ± 0.25 vs. 5.14 ± 0.37 m·s, p ≤ 0.05; d = 1.04), and step length (1.2 ± 0.1 vs. 1.1 ± 0.1 m, p ≤ 0.05; d = 0.80). V[Combining Dot Above]O2peak was significantly (p ≤ 0.05, d = -1.20) higher in backs (54.9 ± 3.9 ml·kg·min) than in forwards (49.4 ± 4.4 ml·kg·min). No differences in agility performance were found between position groups. The results of this study provide descriptive information on anthropometric and performance measures on American male collegiate championship-level rugby players offering potential standards for coaches to use when developing or recruiting players.

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 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 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.

Resistance training does not induce uniform adaptations to quadriceps.

Resistance training may differentially affect morphological adaptations along the length of uni-articular and bi-articular muscles. The purpose of this study was to compare changes in muscle morphology along the length of the rectus femoris (RF) and vastus lateralis (VL) in response to resistance training. Following a 2-wk preparatory phase, 15 resistance-trained men (24.0 ± 3.0 y, 90.0 ± 13.8 kg, 174.9 ± 20.7 cm) completed pre-training (PRE) assessments of muscle thickness (MT), pennation angle (PA), cross-sectional area (CSA), and echo-intensity in the RF and VL at 30, 50, and 70% of each muscle's length; fascicle length (FL) was estimated from respective measurements of MT and PA within each muscle and region. Participants then began a high intensity, low volume (4 x 3-5 repetitions, 3min rest) lower-body resistance training program, and repeated all PRE-assessments after 8 weeks (2 d ∙ wk-1) of training (POST). Although three-way (muscle [RF, VL] x region [30, 50, 70%] x time [PRE, POST]) repeated measures analysis of variance did not reveal significant interactions for any assessment of morphology, significant simple (muscle x time) effects were observed for CSA (p = 0.002) and FL (p = 0.016). Specifically, average CSA changes favored the VL (2.96 ± 0.69 cm2, p < 0.001) over the RF (0.59 ± 0.20 cm2, p = 0.011), while significant decreases in average FL were noted for the RF (-1.03 ± 0.30 cm, p = 0.004) but not the VL (-0.05 ± 0.36 cm, p = 0.901). No other significant differences were observed. The findings of this study demonstrate the occurrence of non-homogenous adaptations in RF and VL muscle size and architecture following 8 weeks of high-intensity resistance training in resistance-trained men. However, training does not appear to influence region-specific adaptations in either muscle.

Monocyte Recruitment after High-Intensity and High-Volume Resistance Exercise.

UNLABELLED: The innate immune response is generally considered to have an important role in tissue remodeling after resistance exercise. PURPOSE: The purpose of this study was to compare changes in markers of monocyte recruitment after an acute bout of high-intensity (HVY) versus high-volume (VOL) lower-body resistance exercise. METHODS: Ten resistance-trained men (24.7 ± 3.4 yr, 90.1 ± 11.3 kg, 176.0 ± 4.9 cm) performed each protocol in a randomized, counterbalanced order. Blood samples were collected at baseline, immediately (IP), 30 min (30P), 1 h (1H), 2 h (2H), and 5 h (5H) postexercise. Plasma concentrations of monocyte chemoattractant protein 1 (MCP-1), tumor necrosis factor alpha (TNF-α), myoglobin, and cortisol were measured via assay. Tumor necrosis factor receptor 1 (TNFr1), macrophage-1 antigen (cluster of differentiation 11b [CD11b]), and C-C chemokine receptor 2 (CCR2) expression levels were measured using flow cytometry. TNFr1 and CD11b were assessed on CD14CD16 monocytes, whereas CCR2 was assessed on CD14 monocytes. RESULTS: Plasma myoglobin concentrations were significantly greater after HVY compared with VOL (P < 0.001). Changes in plasma TNF-α, MCP-1, and expression levels of CCR2 and CD11b were similar between HVY and VOL. When collapsed across groups, TNF-α was significantly increased at IP, 30P, 1H, and 2H (P values < 0.05), whereas MCP-1 was significantly elevated at all postexercise time points (P values < 0.05). CCR2 expression on CD14 monocytes was significantly lower at IP, 1H, 2H, and 5H (P values < 0.05). CD11b expression on CD14 CD16 was significantly greater at IP (P < 0.014) and 1H (P = 0.009). TNFr1 expression did not differ from baseline at any time point. Plasma cortisol concentrations did not seem to be related to receptor expression. CONCLUSIONS: Results indicate that both HVY and VOL protocols stimulate a robust proinflammatory response. However, no differences were noted between resistance exercise training paradigms.

The Effect of Post-Resistance Exercise Amino Acids on Plasma MCP-1 and CCR2 Expression.

The recruitment and infiltration of classical monocytes into damaged muscle is critical for optimal tissue remodeling. This study examined the effects of an amino acid supplement on classical monocyte recruitment following an acute bout of lower body resistance exercise. 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 monocyte chemoattractant protein 1 (MCP-1), myoglobin, cortisol and insulin concentrations; and expressions of C-C chemokine receptor-2 (CCR2), and macrophage-1 antigen (CD11b) on classical monocytes. Magnitude-based inferences were used to provide inferences on the true effects of SUPP compared to PL. Changes in myoglobin, cortisol, and insulin concentrations were similar between treatments. Compared to PL, plasma MCP-1 was "very likely greater" (98.1% likelihood effect) in SUPP at 2H. CCR2 expression was "likely greater" at IP (84.9% likelihood effect), "likely greater" at 1H (87.7% likelihood effect), "very likely greater" at 2H (97.0% likelihood effect), and "likely greater" at 5H (90.1% likelihood effect) in SUPP, compared to PL. Ingestion of SUPP did not influence CD11b expression. Ingestion of an amino acid supplement immediately post-exercise appears to help maintain plasma MCP-1 concentrations and augment CCR2 expression in resistance trained men.

Muscle strength and hypertrophy occur independently of protein supplementation during short-term resistance training in untrained men.

Short-term resistance training has consistently demonstrated gains in muscular strength, but not hypertrophy. Post-resistance training protein ingestion is posited to augment the acute anabolic stimulus, thus potentially accelerating changes in muscle size and strength. The purpose of this investigation was to examine the effects of 4 weeks of resistance training with protein supplementation on strength and muscle morphology changes in untrained men. Participants (mean ± SD; N = 18; age, 22.0 ± 2.5 years; body mass index, 25.1 ± 5.4 kg · m(-2)) were randomly assigned to a resistance training + protein group (n = 9; whey (17 g) + colostrum (3 g) + leucine (2 g)) or a resistance training + placebo group (n = 9). One-repetition maximum (1RM) strength in the leg press (LP) and leg extension (LE) exercises, maximal isometric knee extensor strength (MVIC), and muscle morphology (thickness (MT), cross-sectional area (CSA), pennation angle) of the dominant rectus femoris (RF) and vastus lateralis (VL) was assessed before and after training. Participants performed LP and LE exercises (3 × 8-10; at 80% 1RM) 3 days/week for 4 weeks. Data were analyzed using 2-way ANOVA with repeated measures. Four weeks of resistance training resulted in significant increases in LP (p < 0.001), LE (p < 0.001), MVIC (p < 0.001), RF MT (p < 0.001), RF CSA (p < 0.001), VL MT (p < 0.001), and VL CSA (p < 0.001). No between-group differences were observed. Although nutrition can significantly affect training adaptations, these results suggest that short-term resistance training augments muscle strength and size in previously untrained men with no additive benefit from postexercise protein supplementation.

Effects of ß-Hydroxy-ß-methylbutyrate Free Acid Ingestion and Resistance Exercise on the Acute Endocrine Response.

Objective. To examine the endocrine response to a bout of heavy resistance exercise following acute ß-hydroxy-ß-methylbutyrate free acid (HMB-FA) ingestion. Design. Twenty resistance trained men were randomized and consumed either 1 g of HMB-FA (BetaTor) or placebo (PL) 30 min prior to performing an acute heavy resistance exercise protocol. Blood was obtained before (PRE), immediately after (IP), and 30 min after exercise (30P). Circulating concentrations of testosterone, growth hormone (GH), insulin-like growth factor (IGF-1), and insulin were assayed. Data were analyzed with a repeated measures ANOVA and area under the curve (AUC) was analyzed by the trapezoidal rule. Results. The resistance exercise protocol resulted in significant elevations from PRE in testosterone (P < 0.01), GH (P < 0.01), and insulin (P = 0.05) at IP, with GH (P < 0.01) and insulin (P < 0.01) remaining elevated at 30P. A significant interaction was noted between groups in the plasma GH response at IP, which was significantly higher following HMB-FA compared to PL (P < 0.01). AUC analysis revealed an elevated GH and IGF-1 response in the HMB-FA group compared to PL. Conclusion. HMB-FA prior to resistance exercise augments the GH response to high volume resistance exercise compared to PL. These findings provide further support for the potential anabolic benefits associated with HMB supplementation.

The effect of training volume and intensity on improvements in muscular strength and size in resistance-trained men.

This investigation compared the effect of high-volume (VOL) versus high-intensity (INT) resistance training on stimulating changes in muscle size and strength in resistance-trained men. Following a 2-week preparatory phase, participants were randomly assigned to either a high-volume (VOL; n = 14, 4 × 10-12 repetitions with ~70% of one repetition maximum [1RM], 1-min rest intervals) or a high-intensity (INT; n = 15, 4 × 3-5 repetitions with ~90% of 1RM, 3-min rest intervals) training group for 8 weeks. Pre- and posttraining assessments included lean tissue mass via dual energy x-ray absorptiometry, muscle cross-sectional area and thickness of the vastus lateralis (VL), rectus femoris (RF), pectoralis major, and triceps brachii muscles via ultrasound images, and 1RM strength in the back squat and bench press (BP) exercises. Blood samples were collected at baseline, immediately post, 30 min post, and 60 min postexercise at week 3 (WK3) and week 10 (WK10) to assess the serum testosterone, growth hormone (GH), insulin-like growth factor-1 (IGF1), cortisol, and insulin concentrations. Compared to VOL, greater improvements (P < 0.05) in lean arm mass (5.2 ± 2.9% vs. 2.2 ± 5.6%) and 1RM BP (14.8 ± 9.7% vs. 6.9 ± 9.0%) were observed for INT. Compared to INT, area under the curve analysis revealed greater (P < 0.05) GH and cortisol responses for VOL at WK3 and cortisol only at WK10. Compared to WK3, the GH and cortisol responses were attenuated (P < 0.05) for VOL at WK10, while the IGF1 response was reduced (P < 0.05) for INT. It appears that high-intensity resistance training stimulates greater improvements in some measures of strength and hypertrophy in resistance-trained men during a short-term training period.

Protein supplementation does not alter intramuscular anabolic signaling or endocrine response after resistance exercise in trained men.

The mammalian/mechanistic target of rapamycin complex 1 (mTORC1) signaling pathway appears to be the primary regulator of muscle protein synthesis. A variety of stimuli including resistance exercise, amino acids, and hormonal signals activate mTORC1 signaling. The purpose of this study was to investigate the effect of a protein supplement on mTORC1 signaling following a resistance exercise protocol designed to promote elevations in circulating hormone concentrations. We hypothesized that the protein supplement would augment the intramuscular anabolic signaling response. Ten resistance-trained men (age, 24.7 ± 3.4 years; weight, 90.1 ± 11.3 kg; height, 176.0 ± 4.9 cm) received either a placebo or a supplement containing 20 g protein, 6 g carbohydrates, and 1 g fat after high-volume, short-rest lower-body resistance exercise. Blood samples were obtained at baseline, immediately, 30 minutes, 1 hour, 2 hours, and 5 hours after exercise. Fine-needle muscle biopsies were completed at baseline, 1 hour, and 5 hours after exercise. Myoglobin, lactate dehydrogenase, and lactate concentrations were significantly elevated after resistance exercise (P < .0001); however, no differences were observed between trials. Resistance exercise also elicited a significant insulin, growth hormone, and cortisol response (P < .01); however, no differences were observed between trials for insulin-like growth factor-1, insulin, testosterone, growth hormone, or cortisol. Intramuscular anabolic signaling analysis revealed significant elevations in RPS6 phosphorylation after resistance exercise (P = .001); however, no differences were observed between trials for signaling proteins including Akt, mTOR, p70S6k, and RPS6. The endocrine response and phosphorylation status of signaling proteins within the mTORC1 pathway did not appear to be altered by ingestion of supplement after resistance exercise in resistance-trained men.

Intramuscular anabolic signaling and endocrine response following high volume and high intensity resistance exercise protocols in trained men.

Resistance exercise paradigms are often divided into high volume (HV) or high intensity (HI) protocols, however, it is unknown whether these protocols differentially stimulate mTORC1 signaling. The purpose of this study was to examine mTORC1 signaling in conjunction with circulating hormone concentrations following a typical HV and HI lower-body resistance exercise protocol. Ten resistance-trained men (24.7 ± 3.4 years; 90.1 ± 11.3 kg; 176.0 ± 4.9 cm) performed each resistance exercise protocol in a random, counterbalanced order. Blood samples were obtained at baseline (BL), immediately (IP), 30 min (30P), 1 h (1H), 2 h (2H), and 5 h (5H) postexercise. Fine needle muscle biopsies were completed at BL, 1H, and 5H. Electromyography of the vastus lateralis was also recorded during each protocol. HV and HI produced a similar magnitude of muscle activation across sets. Myoglobin and lactate dehydrogenase concentrations were significantly greater following HI compared to HV (P = 0.01-0.02), whereas the lactate response was significantly higher following HV compared to HI (P = 0.003). The growth hormone, cortisol, and insulin responses were significantly greater following HV compared to HI (P = 0.0001-0.04). No significant differences between protocols were observed for the IGF-1 or testosterone response. Intramuscular anabolic signaling analysis revealed a significantly greater (P = 0.03) phosphorylation of IGF-1 receptor at 1H following HV compared to HI. Phosphorylation status of all other signaling proteins including mTOR, p70S6k, and RPS6 were not significantly different between trials. Despite significant differences in markers of muscle damage and the endocrine response following HV and HI, both protocols appeared to elicit similar mTORC1 activation in resistance-trained men.