Does beta-alanine supplementation enhance adaptations to resistance training? A randomized, placebo-controlled, double-blind study.

The aim of the present study was to assess the effects of beta-alanine supplementation on muscle strength and thickness. Nineteen resistance-trained men (age: 27.3 ± 5.5 years; height: 178 ± 10 cm; body mass: 83.4 ± 9.7 kg; training experience: 5.9 ± 3.9 years) were allocated to one of the following groups: Beta-alanine (BA) (6.4 g/day of beta-alanine) or Placebo (PLA) (6.4 g/day of maltodextrin). Subjects completed 4 resistance training sessions per week for 8 weeks. The following assessments were performed before and after intervention periods: 1 repetition maximum (1RM) and 60%1RM tests in the bench press (60%1RMBENCH) and back squat (60%1RMSQUAT) exercises; muscle thickness assessment of biceps brachialis (MTBB), triceps brachialis (MTTB), and vastus lateralis (MTVL) by ultrasonography. No significant difference between groups was observed for the absolute increase (pre-post intervention) in the 1RMBENCH (mean difference = 0.8 kg; p = 0.679), 1RMSQUAT (mean difference = 0.1 kg; p = 0.992), MTBB (mean difference = 0.7 mm; p = 0.637), MTTB (mean difference = 1.4 mm; p = 0.282), MTVL (mean difference = 1.6 mm; p = 0.311), 60%1RMBENCH (mean difference = 0.5 repetitions; p = 0.670) and 60%1RMSQUAT (mean difference = 0.7 repetitions; p = 0.690). In conclusion, the 8-week training period induced significant strength and morphological responses. However, the addition of beta-alanine supplementation did not enhance these adaptive outcomes.

High Resistance-Training Volume Enhances Muscle Thickness in Resistance-Trained Men.

ABSTRACT: Brigatto, FA, Lima, LEdM, Germano, MD, Aoki, MS, Braz, TV, and Lopes, CR. High resistance-training volume enhances muscle thickness in resistance-trained men. J Strength Cond Res 36(1): 22-30, 2022-This study investigated the effects of different volumes of resistance training (RT) (8 weeks of 16, 24, and 32 weekly sets per muscle group) on muscular strength and hypertrophy. Subjects were pair-matched according to baseline strength and then randomly assigned to 1 of 3 experimental groups: 16 weekly sets per muscle group (G16, n = 9), 24 weekly sets per muscle group (G24, n = 9), or 32 weekly sets per muscle group (G32, n = 9). All other RT variables (e.g., exercise performed, exercise order, weekly frequency, range of repetitions, rest interval between sets and exercises, etc.) were maintained constant. The total load lifted was calculated for every RT session to compare the accumulated external training load among experimental groups across the intervention period. Testing was conducted before intervention (pre) and after 8-week (post-8) periods for maximal voluntary muscle strength (1 repetition maximum [1RM] test for bench press and parallel back squat exercises) and muscle thickness (MT) of the biceps brachii, triceps brachii, and vastus lateralis. The major findings were as follows: (a) all RT volumes increased bench press and parallel back squat 1RM and (b) all RT volumes increased the biceps brachii, triceps brachii, and vastus lateralis MT. The magnitude of increase in 1RM and MT of the lower body when training with 32 weekly sets per muscle group was higher than for 16 weekly sets per muscle group. The magnitude of the increase in MTTB was higher when training with 32 weekly sets than for 16 weekly sets.

Effect of Different Recoveries During HIIT Sessions on Metabolic and Cardiorespiratory Responses and Sprint Performance in Healthy Men.

ABSTRACT: Germano, MD, Sindorf, MAG, Crisp, AH, Braz, TV, Brigatto, FA, Nunes, AG, Verlengia, R, Moreno, MA, Aoki, MS, and Lopes, CR. Effect of different recoveries during HIIT sessions on metabolic and cardiorespiratory responses and sprint performance in healthy men. J Strength Cond Res 36(1): 121-129, 2022-The purpose of this study was to investigate how the type (passive and active) and duration (short and long) recovery between maximum sprints affect blood lactate concentration, O2 consumed, the time spent at high percentages of V̇o2max, and performance. Subjects were randomly assigned to 4 experimental sessions of high-intensity interval training exercise. Each session was performed with a type and duration of the recovery (short passive recovery-2 minutes, long passive recovery [LPR-8 minutes], short active recovery-2 minutes, and long active recovery [LAR-8 minutes]). There were no significant differences in blood lactate concentration between any of the recoveries during the exercise period (p > 0.05). The LAR presented a significantly lower blood lactate value during the postexercise period compared with LPR (p < 0.01). The LPR showed a higher O2 volume consumed in detriment to the active protocols (p < 0.001). There were no significant differences in time spent at all percentages of V̇o2max between any of the recovery protocols (p > 0.05). The passive recoveries showed a significantly higher effort time compared with the active recoveries (p < 0.001). Different recovery does not affect blood lactate concentration during exercise. All the recoveries permitted reaching and time spent at high percentages of V̇o2max. Therefore, all the recoveries may be efficient to generate disturbances in the cardiorespiratory system.

Effect of Resistance Training Frequency on Neuromuscular Performance and Muscle Morphology After 8 Weeks in Trained Men.

Brigatto, FA, Braz, TV, Zanini, TCdC, Germano, MD, Aoki, MS, Schoenfeld, BJ, Marchetti, PH, and Lopes, CR. Effect of resistance training frequency on neuromuscular performance and muscle morphology after 8 weeks in trained men. J Strength Cond Res 33(8): 2104-2116, 2019-The purpose of this study was to investigate the chronic effects of training muscle groups 1 day per week vs. 2 days per week on neuromuscular performance and morphological adaptations in trained men with the number of sets per muscle group equated between conditions. Participants were randomly assigned in 2 experimental groups: 1 session·wk per muscle group (G1, n = 10), where every muscle group was trained once a week with 16 sets or 2 sessions·wk per muscle group (G2, n = 10), where every muscle group was trained twice a week with 8 sets per session. All other variables were held constant over the 8-week study period. No significant difference between conditions for maximal strength in the back squat or bench press, muscle thickness in the elbow extensors, elbow flexors, or quadriceps femoris, and muscle endurance in the back squat and bench press performed at 60% 1 repetition maximum was detected. Effect size favored G2 for some outcome measurements, suggesting the potential of a slight benefit to the higher training frequency. In conclusion, both G1 and G2 significantly enhance neuromuscular adaptations, with a similar change noted between experimental conditions.

High Resistance-Training Frequency Enhances Muscle Thickness in Resistance-Trained Men.

Zaroni, RS, Brigatto, FA, Schoenfeld, BJ, Braz, TV, Benvenutti, JC, Germano, MD, Marchetti, PH, Aoki, MS, and Lopes, CR. High resistance-training frequency enhances muscle thickness in resistance-trained men. J Strength Cond Res 33(7S): S140-S151, 2019-The purpose of this study was to compare the effect a split training routine with muscle groups trained once per week (SPLIT) vs. whole-body split training routine with muscle groups trained 5 days per week (TOTAL) on neuromuscular adaptations in well-trained men. Eighteen healthy men (height = 177.8 ± 6.6 cm; total body mass = 84.4 ± 8.1 kg; age = 26.4 ± 4.6 years) were recruited to participate in this study. The experimental groups were matched according to baseline strength and then randomly assigned to 1 of the 2 experimental groups: SPLIT (n = 9) or TOTAL (n = 9). Prestudy and poststudy testing included 1RM for bench press, parallel back-squat and machine close-grip seated row, as well as an ultrasound analysis of the muscle thickness (MT) of the elbow flexors, triceps brachii, and vastus lateralis. After 8 weeks of training, no significant difference between groups was noted for all 1RM tests (p > 0.05). TOTAL induced a significantly greater increase in MT of the forearm flexors and vastus lateralis (p < 0.05). In conclusion, muscle strength increment is similar regardless of the experimental conditions studied; however, TOTAL may confer a potentially superior hypertrophic effect.

Twice-daily sessions result in a greater muscle strength and a similar muscle hypertrophy compared to once-daily session in resistance-trained men.

BACKGROUND: The present study investigated the mid-term effects of training muscle groups once- versus twice-daily on morphofunctional adaptations in trained men. METHODS: Participants were randomly assigned to 1 of 2 experimental groups: 1 daily session per muscle group (1S, N.=11), where every muscle group was trained once a day or 2 daily sessions per muscle group (2S, N.=12), where every muscle group was trained twice. Testing was conducted before intervention and after 8 weeks for maximal strength (1RM) and muscular endurance (60%1RM) for bench press and parallel back squat exercises, and muscle thickness (MT) of the biceps brachii, triceps brachii, vastus lateralis, anterior quadriceps and pectoralis major. RESULTS: The major findings were as follows: 1) the increase in 1RM back squat was significantly greater in 2S (∆=16.1%) compared to 1S (∆=7.8%) (P<0.05); 2) both groups significantly increased bench press 1RM (1S: ∆=4.6%; 2S: ∆=6.8%), back squat 60% 1RM (1S: ∆=19.0%; 2S: ∆=24.3%), bench press 60% 1RM (1S: ∆=15.4%; 2S: ∆=24.0%) and all MT outcomes (P<0.05 for all), with no differences between experimental groups (1S and 2S). CONCLUSIONS: This study provides evidence that a twice-daily resistance training augments lower-body muscular strength; however, the daily frequency does not seem to have any additive effect on upper-body muscular strength, muscular endurance, and muscle hypertrophy in trained men.

Tri-Set Training System Induces a High Muscle Swelling with Short Time Commitment in Resistance-Trained Subjects: A Cross-Over Study.

The purpose of the present study was to assess performance and morphological acute responses to the tri-set (TRI) resistance-training system. In a random order, 18 subjects (years: 30.0 ± 5.6; weight: 81.8 ± 13.4 kg; height: 173 ± 6.2 cm; RT experience: 4.6 ± 1.7 years) performed 3 exercises targeting the pectoralis major muscle in two different experimental conditions: traditional system (TRAD) and TRI. The TRAD protocol referred to the completion of a single exercise set followed by a rest period. For the TRI protocol, one set of each exercise was performed sequentially with a minimal rest interval afforded (< 10 seconds). Both protocols were performed in 3 sets of 10RM. Pectoralis major muscle swelling (PMMS), volume load (VL), internal training load (ITL) and training efficiency (TE) were calculated and compared between both protocols. Despite the low VL (-19.3%; p < 0.001), larger values of PMMS (104.7%; p < 0.001), ITL (24.3%; p < 0.001) and TE (56.0%; p < 0.001) were observed during TRI compared to TRAD condition. In conclusion, the adoption of a TRI training protocol may induce distinct performance and morphological acute responses compared to TRAD, suggesting that resistance-trained subjects may experience a higher muscle swelling and intensity of effort with short time commitment when performing TRI system.

Acute Effects of Inter-set Stretching on Performance and Metabolic Parameters of Resistance-trained Men.

The present study investigated acute muscular performance and metabolic responses to resistance training (RT) with inter-set stretching (ISS). Seventeen resistance-trained men (age: 30.0 ± 5.6 years; body mass: 81.8 ± 13.4 kg; height: 173 ± 6.2 cm; RT experience: 4.6 ± 1.7 years) completed the ISS and traditional training (TT) protocol seven days apart in a randomized order. In both protocols, 7 sets of the seated cable fly exercise were performed with a 10-repetition maximum (10-RM) load. During the ISS protocol, subjects completed inter-set passive static stretching of the agonist muscles for 45 seconds, while a passive rest (no stretching) was adopted for the same duration in the TT protocol. The change in maximal bench press strength (1-RM), muscle swelling (ultrasound) of the pectoralis major (PMMS), and blood lactate were assessed immediately following each protocol. Additionally, the total load lifted (TLL) and internal training load (ITL) were assessed in both protocols. There was no difference between protocols for the change in maximal bench press 1-RM (p > 0.05). There were higher values for PMMS (p < 0.05) and blood lactate (p < 0.05) following the TT versus the ISS protocol. The TT resulted in higher TLL (p < 0.05) and ITL values (p < 0.05) versus the ISS protocol. Resistance training with inter-set stretching results in lower acute performance and metabolic responses versus traditional training with passive rest between sets. Therefore, inter-set stretching might be applied within a periodized program on lower intensity days to reduce the overall stress of a session.

Different volumes and intensities of static stretching affect the range of motion and muscle force output in well-trained subjects.

The manipulation of the volume and intensity of static stretching (SS) can affect the range of motion (ROM) and muscle force output. The purpose of this study was to investigate the effect of two different SS protocols with different intensities (50% and 85% POD) and volumes (120-s and 240-s) on ROM, peak force, and muscle activity during maximal isometric leg curl exercise in well-trained participants. Fifteen young males (age:27.5 ± 6.1years, height:175.6 ± 4.7cm, and body mass:81.5 ± 10.4kg, 6 ± 2 years of resistance training experience) performed passive hip flexion with two different SS protocols: six stretches of 40-s, with 15-sec rest between each stretch at 50% of the point of discomfort (POD) and three stretches of 40-s, with 15-sec rest between each stretch at 85%POD. The passive hip flexion ROM, biceps femoris muscle activation (integrated electromyography: IEMG), and knee flexors force were monitored during a 3-s maximal voluntary isometric leg curl exercise. ROM increased between pre- and post-intervention for both SS protocols (50%POD: p = 0.016, Δ% = 4.6% and 85%POD: p < 0.001, Δ% = 11.42%). Peak force decreased between pre- and post-intervention only for 85%POD (p = 0.004, Δ% = 23.6%). There were no significant IEMG differences. In conclusion, both SS protocols increased ROM, however, the high-intensity and short-duration SS protocol decreased peak force.

Effect of a short-term whole-body high-intensity interval training on fitness, morphological, and functional parameters in untrained individuals.

BACKGROUND: High-intensity interval training protocols using the body weight (WB-HIIT) as resistance could be an interesting and inexpensive alternative due to the absence of equipment required (low cost) and the possibility to be performed in a wide range of locations. Therefore, the purpose of the present study was to analyze the effects of a short-term WB-HIIT protocol on muscle thickness (MT), muscular endurance (ME), one maximum repetition test (1RM), and maximum oxygen uptake (VO2max) of untrained individuals. METHODS: Fifty healthy men (28.2±6.7 years, 77.5±26.2 kg, 171±10 cm, 23.2±8.2% Fat) were randomized into WB-HIIT (N.=25) or control (CON, N.=25) group. The WB-HIIT performed 9 exercises (40-second stimulus in all out intensity/ 20-second of passive recovery) divided into 3 blocks with 2 sets each for 6 weeks (three times a week). RESULTS: Only WB-HIIT resulted in a significant increase in MT, ME, 1RM, and VO2max (all P<0.05) outcomes and were significantly greater compared to CON (all P<0.05). CONCLUSIONS: Our results demonstrate that a WB-HIIT program can be a time-efficient strategy to promote changes on fitness, morphological and functional parameters in previously untrained sedentary individuals.

Acute Effect of Different Duration of Foam Rolling Protocols on Muscle Thickness, Pain Pressure Threshold, and Volume Load on Multiple Sets of Knee Extension.

Previous studies investigated the effects of foam rolling (FR) on measurements of strength and power. However, the acute effect of FR on muscle thickness (MT) and pressure pain threshold (PPT) after multiple sets of resistance exercise remains to be elucidated. The aim of the present study was to examine the effect of one and three minutes of quadriceps FR on muscle thickness (vastus lateralis [VL] and rectus femoris [RF]), pain threshold (VL and RF), and total load lifted (TLL) on multiple sets of knee extension. Nine resistance-trained men (age: 24.8 ± 5.2 years; height: 177 ± 7 cm; total body mass 77.7 ± 6.2 kg) participated the study. MT, PPT, and performance on multiple sets of knee extension were compared after performing passive recovery (CON), one minute (FR1), or three minutes of FR (FR3). A similar total training load among experimental conditions was observed. There was a greater increase on VL muscle thickness after FR3 when compared to CON and FR1. In addition, there was an increase on rectus femoris PPT two minutes post FR3, with no differences between conditions. These results indicate that longer duration FR-protocol may acutely increase muscle thickness of the vastus lateralis muscle without negatively affect the TLL and PTT.

Multi-joint vs. Single-joint Resistance Exercises Induce a Similar Strength Increase in Trained Men: A Randomized Longitudinal Crossover Study.

The type of exercise is a relevant resistance training-variable that might be manipulated in order to induce significant increases in muscle strength. The aim of this study was to analyze the influence of multi-joint vs single-joint resistance exercises on maximal strength. Sixteen resistance-trained men (age: 23.1 ± 4.4 years; body mass: 86.0 ± 12.8; height: 177.9 ± 6.4 cm; training experience: 4.2 ± 3.4 years) performed one of the following training protocols for six weeks: MULTI, consisting of only multi-joint exercises or SINGLE, consisting of only single-joint exercises. Subjects were then submitted to a three-week washout period, before being submitted to the other protocol for another six weeks. A linear periodization model was adopted in which external load was increased and the repetition range was decreased every two weeks. Maximal dynamic strength of bench press (1RMBENCH) and squat exercises (1RMSQUAT), a percentage variation of total load lifted (ΔTLL) and internal training load (ITL) were measured. Similar increases in 1RMBENCH (MULTI: 10.8%, p < 0.001; SINGLE: 5.5%, p < 0.001) and 1RMSQUAT (MULTI: 19.7%, p < 0.001; SINGLE: 19.0%, p < 0.001) were observed after the MULTI and SINGLE protocols. A decrease in TLL was detected for both exercise protocols; however, the SINGLE protocol induced a greater decrease, compared to the MULTI protocol (-35 ± 11% vs -42 ± 5%, respectively; p = 0.026). A greater ITL for the MULTI was observed when compared to the SINGLE (12.1%; p < 0.001). In conclusion, resistance training protocols with different exercise modalities seem to produce similar strength increases in resistance-trained men.