Protein Supplementation Increases Adaptations to Low-Volume, Intra-Session Concurrent Training in Untrained Healthy Adults: A Double-Blind, Placebo-Controlled, Randomized Trial

Combined endurance and resistance training, also known as "concurrent training", is a common practice in exercise routines. While concurrent training offers the benefit of targeting both cardiovascular and muscular fitness, it imposes greater physiological demands on the body compared to performing each modality in isolation. Increased protein consumption has been suggested to support adaptations to concurrent training. However, the impact of protein supplementation on responses to low-volume concurrent training is still unclear. Forty-four untrained, healthy individuals (27 ± 6 years) performed two sessions/week of low-volume high-intensity interval training on cycle ergometers followed by five machine-based resistance training exercises for 8 weeks. Volunteers randomly received (double-blinded) 40 g of whey-based protein (PRO group) or an isocaloric placebo (maltodextrin, PLA group) after each session. Maximal oxygen consumption (VO2max) and overall fitness scores (computed from volunteers' VO2max and one-repetition maximum scores, 1-RM) significantly increased in both groups. The PRO group showed significantly improved 1-RM in all major muscle groups, while the PLA group only improved 1-RM in chest and upper back muscles. Improvements in 1-RM in leg muscles were significantly greater in the PRO group versus the PLA group. In conclusion, our results indicate that adaptations to low-volume concurrent training, particularly leg muscle strength, can be improved with targeted post-exercise protein supplementation in untrained healthy individuals.

Grass-Fed and Non-Grass-Fed Whey Protein Consumption Do Not Attenuate Exercise-Induced Muscle Damage and Soreness in Resistance-Trained Individuals: A Randomized, Placebo-Controlled Trial

Eccentric muscle contractions can cause structural damage to muscle cells resulting in temporarily decreased muscle force production and soreness. Prior work indicates pasture-raised dairy products from grass-fed cows have greater anti-inflammatory and antioxidant properties compared to grain-fed counterparts. However, limited research has evaluated the utility of whey protein from pasture-raised, grass-fed cows to enhance recovery compared to whey protein from non-grass-fed cows. Therefore, using a randomized, placebo-controlled design, we compared the effect of whey protein from pasture-raised, grass-fed cows (PRWP) to conventional whey protein (CWP) supplementation on indirect markers of muscle damage in response to eccentric exercise-induced muscle damage (EIMD) in resistance-trained individuals. Thirty-nine subjects (PRWP, n = 14; CWP, n = 12) completed an eccentric squat protocol to induce EIMD with measurements performed at 24, 48, and 72 h of recovery. Dependent variables included: delayed onset muscle soreness (DOMS), urinary titin, maximal isometric voluntary contraction (MIVC), potentiated quadriceps twitch force, countermovement jump (CMJ), and barbell back squat velocity (BBSV). Between-condition comparisons did not reveal any significant differences (p ≤ 0.05) in markers of EIMD via DOMS, urinary titin, MIVC, potentiated quadriceps twitch force, CMJ, or BBSV. In conclusion, neither PRWP nor CWP attenuate indirect markers of muscle damage and soreness following eccentric exercise in resistance-trained individuals.

Effect of hot water immersion on acute physiological responses following resistance exercise

Purpose: Hot water immersion (HWI) is a strategy theorised to enhance exercise recovery. However, the acute physiological responses to HWI following resistance exercise are yet to be determined. Methods: The effect of HWI on intramuscular temperature (IMT), muscle function, muscle soreness and blood markers of muscle cell disruption and inflammatory processes after resistance exercise was assessed. Sixteen resistance trained males performed resistance exercise, followed by either 10 min HWI at 40°C or 10 min passive recovery (PAS). Results: Post-intervention, the increase in IMT at all depths was greater for HWI compared to PAS, however this difference had disappeared by 1 h post at depths of 1 and 2 cm, and by 2 h post at a depth of 3 cm. There were no differences between groups for muscle function, muscle soreness or any blood markers. Conclusion: These results suggest that HWI is a viable means of heat therapy to support a greater IMT following resistance exercise. Recovery of muscle function and muscle soreness is independent of acute changes in IMT associated with HWI.

Evaluating the Effects of Increased Protein Intake on Muscle Strength, Hypertrophy and Power Adaptations with Concurrent Training: A Narrative Review

Concurrent training incorporates dual exercise modalities, typically resistance and aerobic-based exercise, either in a single session or as part of a periodized training program, that can promote muscle strength, mass, power/force and aerobic capacity adaptations for the purposes of sports performance or general health/wellbeing. Despite multiple health and exercise performance-related benefits, diminished muscle hypertrophy, strength and power have been reported with concurrent training compared to resistance training in isolation. Dietary protein is well-established to facilitate skeletal muscle growth, repair and regeneration during recovery from exercise. The degree to which increased protein intake can amplify adaptation responses with resistance exercise, and to a lesser extent aerobic exercise, has been highly studied. In contrast, much less focus has been directed toward the capacity for protein to enhance anabolic and metabolic responses with divergent contractile stimuli inherent to concurrent training and potentially negate interference in muscle strength, power and hypertrophy. This review consolidates available literature investigating increased protein intake on rates of muscle protein synthesis, hypertrophy, strength and force/power adaptations following acute and chronic concurrent training. Acute concurrent exercise studies provide evidence for the significant stimulation of myofibrillar protein synthesis with protein compared to placebo ingestion. High protein intake can also augment increases in lean mass with chronic concurrent training, although these increases do not appear to translate into further improvements in strength adaptations. Similarly, the available evidence indicates protein intake twice the recommended intake and beyond does not rescue decrements in selective aspects of muscle force and power production with concurrent training.

Does Protein Supplementation Support Adaptations to Arduous Concurrent Exercise Training? A Systematic Review and Meta-Analysis with Military Based Applications

We evaluated the impact of protein supplementation on adaptations to arduous concurrent training in healthy adults with potential applications to individuals undergoing military training. Peer-reviewed papers published in English meeting the population, intervention, comparison and outcome criteria were included. Database searches were completed in PubMed, Web of science and SPORTDiscus. Study quality was evaluated using the COnsensus based standards for the selection of health status measurement instruments checklist. Of 11 studies included, nine focused on performance, six on body composition and four on muscle recovery. Cohen's d effect sizes showed that protein supplementation improved performance outcomes in response to concurrent training (ES = 0.89, 95% CI = 0.08-1.70). When analysed separately, improvements in muscle strength (SMD = +4.92 kg, 95% CI = -2.70-12.54 kg) were found, but not in aerobic endurance. Gains in fat-free mass (SMD = +0.75 kg, 95% CI = 0.44-1.06 kg) and reductions in fat-mass (SMD = -0.99, 95% CI = -1.43-0.23 kg) were greater with protein supplementation. Most studies did not report protein turnover, nitrogen balance and/or total daily protein intake. Therefore, further research is warranted. However, our findings infer that protein supplementation may support lean-mass accretion and strength gains during arduous concurrent training in physical active populations, including military recruits.

Changes in muscle strength and endurance of professional cyclists due to PycnoRacerTM

[Purpose] Changes in the muscle performance of professional motorized athletes using pycnogenol-containing supplements have not been clarified. The purpose of this study was to evaluate the changes in muscle strength and endurance of professional cyclists during 4 weeks of training with the use of PycnoRacer^TM. [Participants and Methods] Eight professional cyclists were requested to consume PycnoRacer^TM twice/day for 4 weeks. The muscle endurance test consisted of 50 consecutive knee flexion and extension exercises at 180°/sec using an isokinetic torque machine before and after PycnoRacer^TM administration. The athletes’ body composition, including leg muscle mass, was also measured. [Results] The maximum flexor muscle torque and 41st–50th flexion muscle torque values significantly improved after supplement consumption (average improvement of 8.5%; range, 13.3–67.2%). The leg muscle mass and body composition did not differ significantly between the two conditions. The participants showed an average improvement of 31.8% (range, 0.9–67.8%) in their total work with cycling training. No adverse events were observed. [Conclusion] The use of PycnoRacer^TM may improve training, muscle strength, and endurance, but not muscle mass.

Whey protein supplementation does not accelerate recovery from a single bout of eccentric exercise

The current double blind, randomized, placebo-controlled trial with two parallel groups aimed to assess the impact of whey protein supplementation on recovery of muscle function and muscle soreness following eccentric exercise. During a 9-day period, forty recreationally active males received twice daily supplementation with either whey protein (PRO; 60 g/day) or an iso-energetic amount of carbohydrate (CON). Muscle function and soreness were assessed before, and 0, 3, 24, 48, and 72 h after performing 100 drop jumps. Recovery of isometric maximal voluntary contraction (MVC) did not significantly differ between groups (timextreatment, P = 0.56). In contrast, the recovery of isokinetic MVC at 90°·s^-1 was faster in CON as opposed to PRO (timextreatment interaction, P = 0.044). Recovery of isokinetic MVC at 180°·s^-1 was also faster in CON as opposed to PRO (timextreatment interaction, P = 0.011). Recovery of countermovement jump performance did not differ between groups (timextreatment interaction, P = 0.52). Muscle soreness, CK and CRP showed a transient increase over time (P < 0.001), with no differences between groups. In conclusion, whey protein supplementation does not accelerate recovery of muscle function or attenuate muscle soreness and inflammation during 3 days of recovery from a single bout of eccentric exercise.

Protein Supplementation in Sport: Source, Timing, and Intended Benefits

PURPOSE OF REVIEW

The purpose of this review is to provide background on the present literature regarding the utility and effectiveness of protein supplements, including protein source and nutrient timing.

RECENT FINDINGS

In the setting of adequate dietary protein consumption, research suggests some benefit particularly in sport or exercise activities. Protein supplements command a multi-billion-dollar market with prevalent use in sports. Many individuals, including athletes, do not consume optimal dietary protein on a daily basis. High-protein diets are remarkably safe in healthy subjects, especially in the short term. Some objective outcomes are physiologic and may not translate to clinically relevant outcomes. Athletes should, however, consider long-term implications when consuming high quantities of protein in dietary or supplement form.

Nutritional interventions for reducing the signs and symptoms of exercise-induced muscle damage and accelerate recovery in athletes: current knowledge, practical application and future perspectives

PURPOSE

This review provides an overview of the current knowledge of the nutritional strategies to treat the signs and symptoms related to EIMD. These strategies have been organized into the following sections based upon the quality and quantity of the scientific support available: (1) interventions with a good level of evidence; (2) interventions with some evidence and require more research; and (3) potential nutritional interventions with little to-no-evidence to support efficacy.

METHOD

Pubmed, EMBASE, Scopus and Web of Science were used. The search terms 'EIMD' and 'exercise-induced muscle damage' were individually concatenated with 'supplementation', 'athletes', 'recovery', 'adaptation', 'nutritional strategies', hormesis'.

RESULT

Supplementation with tart cherries, beetroot, pomegranate, creatine monohydrate and vitamin D appear to provide a prophylactic effect in reducing EIMD. β-hydroxy β-methylbutyrate, and the ingestion of protein, BCAA and milk could represent promising strategies to manage EIMD. Other nutritional interventions were identified but offered limited effect in the treatment of EIMD; however, inconsistencies in the dose and frequency of interventions might account for the lack of consensus regarding their efficacy.

CONCLUSION

There are clearly varying levels of evidence and practitioners should be mindful to refer to this evidence-base when prescribing to clients and athletes. One concern is the potential for these interventions to interfere with the exercise-recovery-adaptation continuum. Whilst there is no evidence that these interventions will blunt adaptation, it seems pragmatic to use a periodised approach to administering these strategies until data are in place to provide and evidence base on any interference effect on adaptation.

Effects of a Multi-ingredient Beverage on Recovery of Contractile Properties, Performance, and Muscle Soreness After Hard Resistance Training Sessions

Naclerio, F, Larumbe-Zabala, E, Cooper, K, and Seijo, M. Effects of a multi-ingredient beverage on recovery of contractile properties, performance, and muscle soreness after hard resistance training sessions. J Strength Cond Res 34(7): 1884-1893, 2020-Carbohydrate-protein-based supplements have been proposed for maximizing postexercise recovery. This study compared the effects of postworkout supplementation ingesting a multi-ingredient (MTN) vs. carbohydrate alone (CHO) on the recovery of muscle function and perceived of delayed onset of muscle soreness (DOMS) after hard resistance workouts. In a double-blinded, crossover design, 10 resistance trained men (26.9 ± 7.4 years) performed 2 identical 5-day intervention periods while ingesting either MTN or CHO. The subjects performed one workout per day during the first 3 days. Thereafter, they were assessed 1, 24, and 48 hours after the completion of the third workout session. Primary outcome was tensiomyography (muscle displacement [Dm], contraction time [Tc], and contraction velocity [Vc]) of the vastus medialis (VM) and biceps femoris long head (BFLH). Secondary outcomes were performance and DOMS. At 24 hours, both conditions decreased (p < 0.05) Dm (MTN -1.71 ± 1.8, CHO -1.58 ± 1.46 mm) and Vc (MTN -0.03 ± 0.03, CHO 0.03 ± 0.04 m·s) in the VM. At 48 hours, all tensiomyography variables were recovered under the MTN while remained depressed (p < 0.01) in CHO (VM, Dm 1.61 ± 1.60, Vc -0.04 ± 0.04 m·s; BFLH, Dm 1.54 ± 1.52, Vc -0.02 ± 0.02 m·s). Vertical jump performance decreased in CHO, but not in MTN. Although both conditions decreased upper-body strength and power at 1 hour, values returned to baseline in 24 hours for MTM while needed 48 hours in CHO. DOMS similarly increased at both 24 and 48 hours in both conditions. Compared with the ingestion of only carbohydrates, postworkout multi-ingredient supplementation seems to hasten recovery of muscular contractile properties and performance without attenuating DOMS after hard resistance workouts.

Effects of Creatine Supplementation on Lower-Limb Muscle Endurance Following an Acute Bout of Aerobic Exercise in Young Men

We aimed to determine whether creatine supplementation influences lower-limb muscle endurance following an acute bout of aerobic exercise (AE) in young healthy men. Using a randomized, double-blind, placebo-controlled crossover design, 11 men (26.5 ± 6.2 years, body mass index 26.6 ± 2.1 kg/m²),with 12 months of experience in strength training (three times/week) and AE (two times/week) were randomized to receive creatine (20 g/day plus 20 g/day maltodextrin) and placebo (40 g/day maltodextrin) for 7 days, separated by a washout period of 14 days, before performing an acute bout of AE (30 min on treadmill at 80% baseline maximum velocity) which was followed by four sets of bilateral leg extension endurance exercise using a 10-repetition maximum protocol (10 RM)). There was a significant decrease in the number of repetitions performed in the third (Placebo: −20% vs. Creatine: −22%) and fourth set (Placebo: −22% vs. Creatine: −28%) compared with the first set (p < 0.05), with no differences between creatine and placebo. Additionally, no differences were observed between creatine and placebo for the total number of repetitions performed across all four sets (Placebo: 33.9 ± 7.0 vs. Creatine: 34.0 ± 6.9 repetitions, p = 0.97), nor for total work volume (Placebo: 3030.5 ± 1068.2 vs. Creatine: 3039.8 ± 1087.7 kg, p = 0.98). Short-term creatine supplementation has no effect on lower-limb muscle endurance following an acute bout of aerobic exercise in trained young men.

β-Hydroxy-β-Methylbutyrate Free Acid Attenuates Oxidative Stress Induced by a Single Bout of Plyometric Exercise

PURPOSE

The purpose of this study was to examine the effect of β-hydroxy-β methylbutyrate free acid (HMB-FA) ingestion on oxidative stress and leukocyte responses to plyometric exercise.

METHODS

In a randomized double-blind placebo-controlled design, physically active males were assigned to the HMB-FA (n = 8) or placebo (n = 8) groups that consumed either 1 g of HMB-FA or placebo 30 min prior to performing an acute plyometric exercise protocol (15 sets of 10 repetitions of maximal-effort vertical jumps). Blood was obtained pre-(T1), post-(T2), and 1-h post-(T3) exercise to determine changes in serum levels of 8-hydroxy-2-deoxyguanosine (8-OHdG), malondialdehyde (MDA), protein carbonyl (PC), and white blood cells (WBC).

RESULTS

The exercise protocol significantly elevated 8-OHdG (HMB-FA, T2 9.5 and T3 12.6%; placebo, T2 18.2 and T3 36.5%), MDA (HMB-FA, T2 11.6 and T3 25.2%; placebo, T2 11.8 and T3 41%) and PC (HMB-FA, T2 6.9 and T3 25%; placebo, T2 23.4 and T3 55.3%) at post- and 1-h post-exercise, respectively. However, at 1-h post-exercise, greater increases in oxidative stress markers (8-OHdG 36.5 vs. 12.6%; MDA 41 vs. 25.1% and PC 55.3 vs. 25%) were observed in the placebo group compared to the HMB-FA group (p < 0.05). In addition, the WBC level was greater for the placebo group in comparison to the HMB-FA group at post-exercise.

CONCLUSION

HMB-FA attenuated oxidative stress and leukocyte responses to plyometric exercise compared with placebo.

Assessing the usefulness of acute physiological responses following resistance exercise: sensitivity, magnitude of change, and time course of measures

A variety of strategies exist to modulate the acute physiological responses following resistance exercise aimed at enhancing recovery and/or adaptation processes. To assess the true impact of these strategies, it is important to know the ability of different measures to detect meaningful change. We investigated the sensitivity of measures used to quantify acute physiological responses to resistance exercise and constructed a physiological profile to characterise the magnitude of change and the time course of these responses. Eight males accustomed to regular resistance exercise performed experimental sessions during a “control week”, void of an exercise stimulus. The following week, termed the “exercise week”, participants repeated this sequence of experimental sessions, and they also performed a bout of lower-limb resistance exercise following the baseline assessments. Assessments were conducted at baseline and at 2, 6, 24, 48, 72, and 96 h after the intervention. On the basis of the signal-to-noise ratio, the most sensitive measures were maximal voluntary isometric contraction, 20-m sprint, countermovement jump peak force, rate of force development (100–200 ms), muscle soreness, Daily Analysis Of Life Demands For Athletes part B, limb girth, matrix metalloproteinase-9, interleukin-6, creatine kinase, and high-sensitivity C-reactive protein with ratios >1.5. Clear changes in these measures following resistance exercise were determined via magnitude-based inferences. These findings highlight measures that can detect real changes in acute physiological responses following resistance exercise in trained individuals. Researchers investigating strategies to manipulate acute physiological responses for recovery and/or adaptation can use these measures, as well as the recommended sampling points, to be confident that their interventions are making a worthwhile impact.

Effects of oat protein supplementation on skeletal muscle damage, inflammation and performance recovery following downhill running in untrained collegiate men

The positive influence of animal-based protein supplementation during muscle-damaging exercise has been widely studied. However, the effects of plant-based proteins remain unclear and require further clarification. This study investigated the protective role of oat protein against exercise induced muscle damage (EIMD), subsequent inflammation, and loss of performance induced by downhill running. Subjects consumed either oat protein (25 g protein) or a placebo for 14 days prior to a downhill running test and then for 4 days thereafter. Treatments with oat protein for 19 days markedly alleviated eccentric exercise induced skeletal muscle soreness, and reduced the elevation of plasma IL-6 concentrations and serum creatine kinase, myoglobin and C reactive protein contents. In addition, oat protein supplementation significantly inhibited limb edema following damaging exercise, and the adverse effects on muscle strength, knee-joint range of motion, and vertical jump performance were lessened. Furthermore, the administration of oat protein facilitated recovery from exhaustive downhill running in this study. These findings demonstrated that oat protein supplementation has the potential to alleviate the negative effects of eccentric exercise in untrained young males.

A Moderate Supplementation of Native Whey Protein Promotes Better Muscle Training and Recovery Adaptations Than Standard Whey Protein - A 12-Week Electrical Stimulation and Plyometrics Training Study

The purpose of this study was to assess if native whey protein (NW) supplementation could promote recovery and training adaptations after an electrostimulation (ES) training program combined to plyometrics training. Participants were allocated into three groups, supplemented 5 days/week, either with 15 g of carbohydrates + 15 g of NW (n = 17), 15 g of carbohydrates + 15 g of standard whey protein (SW; n = 15), or placebo (PLA; 30 g of carbohydrates; n = 10), while undergoing a 12-week ES training program of the knee extensors. Concentric power (Pmax) was evaluated before, immediately after, as well as 30 min, 60 min, 24 h, and 48 h after the 1st, 4th and last ES training session. The maximal voluntary contraction torque (MVC), twitch amplitude, anatomical cross-sectional area (CSA) and maximal voluntary activation level (VA) were measured before (T0), and after 6 (T1) and 12 weeks of training (T2). P_max recovery kinetics differed between groups (p < 0.01). P_max started to recover at 30 min in NW, 24 h in SW and 48 h in PLA. Training adaptations also differed between groups: MVC increased between T0 and T2 in NW (+11.8%, p < 0.001) and SW (+7.1%, p < 0.05), but not PLA. Nevertheless, the adaptation kinetics differed: MVC increased in NW and SW between T0 and T1, but an additional gain was only observed between T1 and T2 in NW. VA declined at T1 and T2 in PLA (−3.9%, p < 0.05), at T2 in SW (−3.5%, p < 0.05), and was unchanged in NW. CSA increased, but did not differ between groups. These results suggest that NW could promote a faster recovery and neuromuscular adaptations after training than SW. However, the mechanisms underlying this effect remain to be identified.

The Effect of Whey Protein Supplementation on the Temporal Recovery of Muscle Function Following Resistance Training: A Systematic Review and Meta-Analysis

Whey protein (WP) is a widely consumed nutritional supplement, known to enhance strength and muscle mass during resistance training (RT) regimens. Muscle protein anabolism is acutely elevated following RT, which is further enhanced by WP. As a result, there is reason to suggest that WP supplementation may be an effective nutritional strategy for restoring the acute loss of contractile function that occurs following strenuous RT. This systematic review and meta-analysis provides a synthesis of the literature to date, investigating the effect of WP supplementation on the recovery of contractile function in young, healthy adults. Eight studies, containing 13 randomised control trials (RCTs) were included in this review and meta-analysis, from which individual standardised effect sizes (ESs) were calculated, and a temporal overall ES was determined using a random-effects model. Whilst only half of the individual studies reported beneficial effects for WP, the high-quality evidence taken from the 13 RCTs was meta-analysed, yielding overall positive small to medium effects for WP from < 24 to 96 h (ES range = 0.4 to 0.7), for the temporal restoration of contractile function compared to the control treatment. Whilst the effects for WP were shown to be consistent over time, these results are limited to 13 RCTs, principally supporting the requirement for further comprehensive research in this area.