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Background: Citrulline malate (CM), especially when used in conjunction with physical exercise, has demonstrated potential as a non-pharmacological adjunct in the management of hypertension. Nevertheless, its impact on nocturnal blood pressure dipping remains unexplored. Objective: Evaluate the impact of a single dose of CM on nocturnal blood pressure dipping after exercise in hypertensive individuals. Methods: In a double-blind, placebo-controlled, parallel-group clinical trial, twenty hypertensive adults (55 ± 16 years) were randomly assigned to either a CM (6 g) or placebo (6 g of corn starch) group (PLA). Resting blood pressure was measured after a 20-min period of comfortable seating in a calm environment. Both groups underwent 40 min of treadmill running/walking at an intensity of 60–70% of their reserve heart rate, 120 min after ingesting the substances. Ambulatory blood pressure monitoring was employed to measure blood pressure over 24 h. Results: No significant differences in systolic blood pressure values were observed between the CM and PLA groups at rest, during wakefulness, sleep, or over a 24-h period. However, CM exhibited a significant reduction in diastolic blood pressure in several metrics: delta 24 h (-14 mmHg vs −6 mmHg, p = 0.047), delta wakefulness (-12 mmHg vs −4 mmHg, p = 0.024), percent delta 24 h (-16% vs −6%, p = 0.024), and percent delta wakefulness (-14% vs −4%, p = 0.013). No significant differences were found between CM and PLA in terms of systolic and diastolic nocturnal absolute reductions (-13 mmHg vs −12 mmHg, p = 0.808, and −13 mmHg vs −8 mmHg, p = 0.273, respectively) or nocturnal percentage decrease (-9.9% vs −9.4%, p = 0.844, and −15.3% vs −11.7%, p = 0.399, respectively). Conclusions: The study found no significant changes in the post-exercise nocturnal blood pressure dip following a single dose of CM supplementation. However, a notable reduction in diastolic blood pressure was observed during the waking period and over the average 24-h monitoring period. Clinical trial registry number and website: ClinicalTrials.gov platform (NCT03378596). [ABSTRACT FROM AUTHOR]

The purpose of this study was to investigate the effects of supplementation of whey protein (WP) versus leucine-matched collagen peptides (CP) on muscle thickness MT and performance after a resistance training (RT) program in young adults. Twenty-two healthy untrained participants were randomly assigned to either a WP (n = 11) or leucine-matched CP (n = 11) group and then submitted to a supervised 10-week RT program (3 days/week). The groups were supplemented with an equivalent amount of WP (35 g, containing 3.0 g of leucine) and CP (35 g, containing 1.0 g of leucine and 2.0 g of free leucine) during the intervention period (after each workout and in the evening on nontraining days). MT of the vastus lateralis and biceps brachii, isokinetic peak torque and mean power output of the elbow flexors, and peak power output of the lower body were assessed before and after the RT program. The WP group experienced a greater (interaction, p <.05) increase in the vastus lateralis (effect size, WP = 0.68 vs. CP = 0.38; % Δ, WP = 8.4 ± 2.5 vs. CP = 5.6 ± 2.6%) and biceps brachii muscle thickness (effect size, WP = 0.61 vs. CP = 0.35; % , WP = 10.1 ± 3.8 vs. CP = 6.0 ± 3.2%), with a similar increase in muscle performance (peak torque, mean power output, and peak power output) between groups (time p <.05). Supplementation with WP was superior to leucine content-matched CP supplementation in increasing muscle size, but not strength and power, after a 10-week RT program in young adults. [ABSTRACT FROM AUTHOR]

Context: Chronic low-back pain (CLBP) may be associated with changes in postural balance in athletes as poor postural control during sports practice. Objective: To compare the postural control of athletes with and without CLBP during 2 one-legged stance tasks and identify the center of pressure (COP) cutoff values to determine the main differences. Designed: A cross-sectional study. Setting: Laboratory of functional evaluation and human motor performance. Participants: A total of 56 male athletes, 28 with and 28 without CLBP (mean age = 26 y). Intervention: The one-legged stance with knee extension and with the knee at 30° flexion tasks were measured and analyzed on a force platform. The participants completed three 30-second trials (30 s of rest between each trial). Main Outcome Measures: The COP parameters: the area of COP, mean COP sway velocity in both the anteroposterior and mediolateral directions, and total COP displacement were computed, and a receiver operating characteristics curve analysis was applied to determine the group differences. Results: Athletes with CLBP had poorer postural control (P <.01) in both tasks. The 30° knee flexion reported more postural instability than the knee extension for all COP parameters (a large effect size d = 0.80).The knee extension cutoffs identified were >7.1 cm2 for the COP area, >2.6 cm/s for the COP sway velocity in the anterior-posterior direction, and >3.2 cm/s for the mediolateral direction. Whereas, the 30° knee flexion cutoffs were >10.9 cm2 for the COP area, >2.9 cm/s for the COP sway velocity in the anterior-posterior direction, and >4.1 cm/s for the mediolateral direction. Both measures showed enough sensitivity and specificity (ie, area under the curve = 0.88 in and 0.80, respectively) to discriminate both groups. Conclusions: The athletes with CLBP had poorer postural control than the healthy athletes and obtained specific cutoff scores from the COP values. [ABSTRACT FROM AUTHOR]

This study aimed to compare the effects of resistance training performed with low versus moderate loads on systemic resting blood pressure (BP) in older women. A total of 29 women (72.6 ± 5.1 years) were randomized into two groups: low load (LOW, n = 15) and moderate load (MOD, n = 14). An 8-week whole-body resistance training program was carried out 3 days/week (eight exercises, three sets, 10 or 15 repetition maximum). The LOW and MOD groups trained with a relative load of 15 and 10 repetition maximum, respectively. Outcome measures included resting systolic and diastolic BP. After 8 weeks, both groups presented significant changes (p <.05) in systolic BP (LOW = −3.0%; MOD = −4.6%) and mean BP (LOW = −1.9%; MOD = −3.1%). There was no change for diastolic BP in the posttest in both groups. The results suggest that low and moderate loads are equally effective for promoting decreases in resting BP in older women. [ABSTRACT FROM AUTHOR]

The authors aimed to compare the effects of creatine (Cr) supplementation combined with resistance training on skeletal muscle mass (SMM), total body water, intracellular water (ICW), and extracellular water (ECW) in resistance-trained men as well as to determine whether the SMM/ICW ratio changes in response to the use of this ergogenic aid. Twenty-seven resistance-trained men received either Cr (n = 14) or placebo (n = 13) over 8 weeks. During the same period, subjects performed two split resistance training routines four times per week. SMM was estimated from appendicular lean soft tissue assessed by dual-energy X-ray absorptiometry. Total body water, ICW, and ECW were determined by spectral bioelectrical impedance. Both groups showed improvements (p <.05) in SMM, total body water, and ICW, with greater values observed for the Cr group compared with placebo. ECW increased similarly in both groups (p <.05). The SMM/ICW ratio did not change in either group (p >.05), whereas the SMM/ECW ratio decreased only in the Cr group (p <.05). A positive correlation was observed (p <.05) between SMM and ICW changes (r =.71). The authors' results suggest that the increase in muscle mass induced by Cr combined with resistance training occurs without alteration of the ratio of ICW to SMM in resistance-trained men. [ABSTRACT FROM AUTHOR]

The main purpose of this study was to compare the effects of resistance training (RT) performed two versus three times per week on phase angle (a cellular health indicator) in older women. A total of 39 women (69.1 ± 5.5 years) were randomly assigned to perform a RT program two (G2X) or three (G3X) days per week for 12 weeks. The RT was a whole-body program (eight exercises, one set, 10–15 repetitions). Phase angle, resistance, reactance, and total body water were assessed by bioimpedance spectroscopy. Intracellular water, reactance, and phase angle increased significantly in G2X (2.1%, 3.0%, and 5.6%, respectively) and G3X (5.0%, 6.9%, and 10.3%, respectively) from pretraining to posttraining, with no significant difference between groups. Bioimpedance resistance decreased similarly in both groups (G2X = −1.7% vs. G3X = −3.2%). We conclude that a single set RT program with a frequency of 2 days per week may be sufficient to promote an improvement in cellular health in older women. [ABSTRACT FROM AUTHOR]

Although the ergogenic mechanisms of supplementation with citrulline malate are well known, unclear findings regarding variables of muscle strength have been recorded. Such misleading findings in the literature illustrate the need for well-conducted meta-analysis research to elucidate the possible ergogenic impact, which could have major practical consequences for athletes and recreational practitioners seeking to optimize gains in muscle strength. The objective of this systematic review was to summarize the existing literature that evaluated the effects of citrulline malate supplementation on muscle strength outcomes from resistance exercise in resistance-trained individuals. A systematic electronic search in Medline and Scientific Electronic Library Online (SciELO) was completed in August 2020 identifying randomized controlled trials investigating the effect of citrulline malate supplementation on muscle strength in resistance-trained adults. A subsequent meta-analysis was performed. The meta-analysis involved four studies and 138 assessments (69 in citrulline-malate and 69 in placebo groups). We did not observe an overall effect favoring citrulline-malate supplementation (SMD95% = 0.13 [−0.21; 0.46]). Considering the lower (SMD95% = 0.06 [−0.47; 0.60]) and upper (SMD95% = 0.17 [−0.26; 0.60]) limbs, a non-significant overall effect was identified. The mean effects were similar for "limbs" (upper vs lower) [p = 0.763]. Accordingly, our findings suggest that citrulline malate supplementation does not improve muscle strength in healthy and resistance-trained individuals (PROSPERO registration number: CRD42020159338). [ABSTRACT FROM AUTHOR]

J Strength Cond Res 24(1): 88-96, 2010--The purpose of this study was to utilize a rodent model to test the hypothesis that creatine (Cr) supplementation during resistance training would influence the pattern of slow-twitch muscle myosin heavy chain (MHC) isoforms expression. Male Wistar rats (2-3 months old, 250-300 g) were divided into 4 groups: Nontrained without creatine supplementation (CO), nontrained with creatine supplementation (CR), trained without creatine supplementation (TR), and trained with creatine supplementation (TRCR). TR and TRCR groups were submitted to a resistance training program for 5 weeks (5 days/week) for morphological and biochemical analysis of the soleus muscle. Weightlifting exercise involved jump sessions into water, carrying progressive overload equivalent to percentage of body weight. CR and TRCR groups were given creatine at 0.5 g/[kg.sup.-1]/[d.sup.-1]. Both Cr supplementation and resistance training alone or associated did not result in significant alterations (p > 0.05) in body weight gain, food intake, and muscle weight in the CR, TR and TRCR groups compared to the CO group. Also compared to the CO group, the CR group showed a significant (p < 0.02) increase in MHCI content and a reduction in MHCII; inversely, the TR group increased the MHCII content and reduced MHCI (p < 0.02). When combined, both creatine and resistance training did not promote significant (p > 0.05) changes in MHC content of the TRCR group compared to the CO group. The data show that Cr supplementation provides a potential action to abolish the exercise-induced MHC isoform transitions from slow to fast in slow-twitch muscle. Thus, Cr supplementation might be a suitable strategy to maintaining a slow phenotype in slow muscle during resistance training, which may be favorable to maintenance of muscle oxidative capacity of endurance athletes. KEY WORDS skeletal muscle, muscle plasticity, weight training, nutritional intervention, soleus muscle

The effects of citrulline malate (CM) on muscle recovery from resistance exercise remains unknown. We aimed to determine if citrulline malate supplementation improves muscle recovery after a single session of high-intensity resistance exercise (RE) in untrained young adult men. Nine young adult men (24.0 ± 3.3 years) participated in a double-blind crossover study in which they received 6 g of CM and placebo (PL) on two occasions, separated by a seven-day washout period. Each occasion consisted of a single session of high-intensity RE (0 h) and three subsequent fatigue tests sessions (at 24, 48, and 72 h) to assess the time course of muscle recovery. During the tests sessions, we assessed the following variables: number of maximum repetitions, electromyographic signal (i.e., root mean square (RMS) and median frequency (MF)), muscle soreness and perceived exertion, as well as blood levels of creatine kinase (CK), lactate, insulin, and testosterone:cortisol ratio. CK levels increased at 24 h post-exercise and remained elevate at 48 and 72 h, with no difference between CM and PL conditions. Muscle soreness increased at 24 h post-exercise, which progressively returned to baseline at 72 h in both conditions. Lactate levels increased immediately post-exercise and remained elevated at 24,48, and 72 h in both conditions. No significant treatment x time interaction was found for all dependents variables (maximum repetitions, perceived exertion, CK, lactate, RMS, MF, and testosterone:cortisol ratio) during the recovery period. In conclusion, our data indicate that CM supplementation (single 6 g dose pre-workout) does not improve the muscle recovery process following a high-intensity RE session in untrained young adult men. [ABSTRACT FROM AUTHOR]

This study's purpose was to compare the effects of different carbohydrate (CHO) intakes on body composition and muscular strength following eight weeks of resistance training (RT) in pre-conditioned men. In addition, we explored the individual responses to different CHO intakes. Twenty-nine young men volunteered to participate in this study. The participants were divided into two groups according to their relative CHO intake: lower (L-CHO; n = 14) and higher (H-CHO; n = 15). Participants performed a RT program four days a week for eight weeks. The lean soft tissue (LST) and fat mass were determined by dual-energy X-ray absorptiometry. Muscular strength was determined by a one-repetition maximum (1RM) test in the bench press, squat, and arm curl exercises. Both groups increased LST ( P < 0.05) with no statistical differences between conditions (L-CHO = +0.8% vs. H-CHO = +3.5%). Neither group demonstrated changes in fat mass. Both groups increased 1RM ( P < 0.05) in the bench press (L-CHO = +3.6% vs. H-CHO = +5.8%) and squat (L-CHO = +7.5% vs. H-CHO = +9.4%); however, only H-CHO significantly increased arm curl 1RM ( P < 0.05) at post-training (L-CHO = +3.0% vs. H-CHO = +6.6%). Responsiveness was greater in H-CHO vs. L-CHO for LST and arm curl 1RM. In conclusion, lower and higher CHO intakes promote similar increase in LST and muscular strength; however, a greater intake may improve the responsiveness to gains in lean mass and arm curl strength in pre-conditioned men.

Context: Chronic low-back pain (CLBP) may be associated with changes in postural balance in athletes as poor postural control during sports practice., Objective: To compare the postural control of athletes with and without CLBP during 2 one-legged stance tasks and identify the center of pressure (COP) cutoff values to determine the main differences. Designed: A cross-sectional study., Setting: Laboratory of functional evaluation and human motor performance., Participants: A total of 56 male athletes, 28 with and 28 without CLBP (mean age = 26 y)., Intervention: The one-legged stance with knee extension and with the knee at 30° flexion tasks were measured and analyzed on a force platform. The participants completed three 30-second trials (30 s of rest between each trial)., Main Outcome Measures: The COP parameters: the area of COP, mean COP sway velocity in both the anteroposterior and mediolateral directions, and total COP displacement were computed, and a receiver operating characteristics curve analysis was applied to determine the group differences., Results: Athletes with CLBP had poorer postural control (P < .01) in both tasks. The 30° knee flexion reported more postural instability than the knee extension for all COP parameters (a large effect size d = 0.80).The knee extension cutoffs identified were >7.1 cm2 for the COP area, >2.6 cm/s for the COP sway velocity in the anterior-posterior direction, and >3.2 cm/s for the mediolateral direction. Whereas, the 30° knee flexion cutoffs were >10.9 cm2 for the COP area, >2.9 cm/s for the COP sway velocity in the anterior-posterior direction, and >4.1 cm/s for the mediolateral direction. Both measures showed enough sensitivity and specificity (ie, area under the curve = 0.88 in and 0.80, respectively) to discriminate both groups., Conclusions: The athletes with CLBP had poorer postural control than the healthy athletes and obtained specific cutoff scores from the COP values.