The Effects of a Protease Enzyme Blend on Post-Resistance Exercise Intramuscular Anabolic Signaling

Abstract Objectives Protease supplementation has been reported to decrease inflammation and indices of muscle damage while increasing functional recovery following strenuous resistance exercise compared to a placebo. While various mechanisms have been proposed, the effects of protease supplementation on the resistance exercise induced anabolic signaling response has not been reported in the literature. To examine the effects of a protease enzyme blend added to whey protein on post-resistance exercise intramuscular anabolic signaling. Methods Ten resistance-trained males (24.4 ± 4.1yrs, 1.79 ± 0.86 m, 92.6 ± 10.4 kg) were enrolled in this double-blind, cross-over, placebo controlled study and engaged in three separate bouts of resistance exercise. Each participant completed 4 sets of leg presses and leg extensions for 8–10 repetitions at 75% of their 1-repetition maximum with 90 seconds of rest between each set. Immediately following the resistance exercise protocol, participants consumed either 250 mg of a protease enzyme blend + 26 g of whey protein (PW), 26 g whey alone (W), or non-caloric control (CON) in a counterbalanced fashion. Skeletal muscle microbiopsies were obtained from the vastus lateralis pre-exercise (PRE), 1-hour (1H), and 3-hours (3H) post-exercise. Multiplex signaling assay kits were used to quantify the phosphorylation status of proteins specific to the mTOR (AKT, mTOR, p70S6K) and MAPK (ERK1/2, JNK, p38) signaling pathways using the MAGPIX® (Luminex, Austin, TX, USA). A 2-way repeated measures analysis of variance (ANOVA) was used to identify differences between treatments over time. Results A main effect for time (p < 0.05) revealed phosphorylation of AKT was decreased at 1H (p < 0.001), mTOR was increased at 1H (P = 0.025) and 3H (P = 0.009) post-exercise, while p70S6K remained unchanged (P > 0.05) from PRE. A main effect for time (p < 0.05) was found with increased phosphorylation at 1H for JNK (P = 0.001), and decreased phosphorylation at 3H for ERK 1/2 (P = 0.022) with respect to baseline. Additionally, there were no differences in any mTOR nor MAPK signaling proteins observed between treatments. Conclusions These data suggest that acute protease supplementation may not alter mTOR or MAPK signaling in skeletal muscle following acute resistance exercise. Funding Sources Deerland Enzymes, Kennesaw, GA.

Download Full-text

Expression of titin-linked putative mechanosensing proteins in skeletal muscle after power resistance exercise in resistance-trained men

Journal of Applied Physiology ◽

10.1152/japplphysiol.00711.2020 ◽

2020 ◽

Author(s):

Stefan G. Wette ◽

Nigel P. Birch ◽

Matthias Soop ◽

Martina Zügel ◽

Robyn M. Murphy ◽

...

Keyword(s):

Skeletal Muscle ◽

Creatine Kinase ◽

Resistance Exercise ◽

Vastus Lateralis ◽

Cytoskeletal Proteins ◽

Muscle Sample ◽

Post Exercise ◽

Protein Levels ◽

Ankyrin Repeat Proteins ◽

Muscle Remodeling

Little is known about the molecular responses to power resistance exercise that lead to skeletal muscle remodeling and enhanced athletic performance. We assessed the expression of titin-linked putative mechanosensing proteins implicated in muscle remodeling: muscle ankyrin repeat proteins (Ankrd1, Ankrd2 and Ankrd23), muscle-LIM proteins (MLP), muscle RING-finger protein-1 (MuRF-1), and associated myogenic proteins (MyoD1, myogenin, and myostatin) in skeletal muscle in response to power resistance exercise with or without a post-exercise meal, in fed, resistance-trained men. A muscle sample was obtained from the vastus lateralis of seven healthy men on separate days, 3h after 90 min of rest (Rest) or power resistance exercise with (Ex+Meal) or without (Ex) a post-exercise meal, to quantify mRNA and protein levels. The levels of phosphorylated HSP27 (pHSP27-Ser15) and cytoskeletal proteins in muscle and creatine kinase activity in serum were also assessed. The exercise increased (P≤0.05) pHSP27-Ser15 (~6-fold) and creatine kinase (~50%), whereas cytoskeletal protein levels were unchanged (P>0.05). Ankrd1 (~15-fold) and MLP (~2-fold) mRNA increased, whereas Ankrd2, Ankrd23, MuRF-1, MyoD1, and myostatin mRNA were unchanged. Ankrd1 (~3-fold, Ex) and MLPb (~20-fold, Ex+Meal) protein increased, but MLPa, Ankrd2, Ankrd23, and the myogenic proteins were unchanged. The post-exercise meal did not affect the responses observed. Power resistance exercise, as performed in practice, induced subtle early responses in the expression of MLP and Ankrd1, yet had little effect on the other proteins investigated. These findings suggest possible roles for MLP and Ankrd1 in the remodeling of skeletal muscle in individuals who regularly perform this type of exercise.

Download Full-text

The Effect of ProHydrolase® on the Amino Acid and Intramuscular Anabolic Signaling Response to Resistance Exercise in Trained Males

Sports ◽

10.3390/sports8020013 ◽

2020 ◽

Vol 8 (2) ◽

pp. 13 ◽

Cited By ~ 1

Author(s):

Jeremy R. Townsend ◽

Jaclyn E. Morimune ◽

Megan D. Jones ◽

Cheryle N. Beuning ◽

Allison A. Haase ◽

...

Keyword(s):

Amino Acid ◽

Resistance Exercise ◽

Whey Protein ◽

Double Blind Study ◽

Double Blind ◽

Post Exercise ◽

Leg Extension ◽

Protease Enzyme ◽

Plasma Leucine ◽

Amino Acid Concentrations

This double-blind study examined effects of a protease enzyme blend (Prohydrolase®) added to whey protein on post-resistance exercise aminoacidemia and intramuscular anabolic signaling were investigated in ten resistance-trained males. Participants completed 4 sets of 8–10 repetitions in the leg press and leg extension exercises at 75% of 1-repetition maximum. Participants then consumed either 250 mg of Prohydrolase® + 26 g of whey protein (PW), 26 g whey alone (W), or non-nutritive control (CON) in counterbalanced order. Blood samples were obtained prior to exercise (baseline) and then immediately-post (IP), 30-, 60-, 90-, 120-, and 180-min post-exercise. Muscle biopsies were taken at baseline, 1-h (1H), and 3-h (3H) post-exercise. Phosphorylation of AKTSer437 was decreased (3H only: p < 0.001), mTORSer2448 was increased (1H: p = 0.025; 3H: p = 0.009), and p70S6KThr412 remained unchanged similarly for each condition. Plasma leucine, branch-chained amino acids, and essential amino acid concentrations for PW were significantly higher than CON (p < 0.05) at 30 min and similar to W. Compared to IP, PW was the only treatment with elevated plasma leucine levels at 30 min (p = 0.007; ∆ = 57.8 mmol/L, 95% Confidence Interval (CI): 20.0, 95.6) and EAA levels at 180 min (p = 0.003; ∆ = 179.1 mmol/L, 95% CI: 77.5, 280.7). Area under the curve amino acid analysis revealed no differences between PW and W. While no different than W, these data indicate that PW was the only group to produce elevated amino acid concentrations 30-min and 180-min post-ingestion.

Download Full-text

Effect of aerobic and resistance exercise on the mitochondrial peptide MOTS-c in Hispanic and Non-Hispanic White breast cancer survivors

Scientific Reports ◽

10.1038/s41598-021-96419-z ◽

2021 ◽

Vol 11 (1) ◽

Cited By ~ 1

Author(s):

Christina M. Dieli-Conwright ◽

Nathalie Sami ◽

Mary K. Norris ◽

Junxiang Wan ◽

Hiroshi Kumagai ◽

...

Keyword(s):

Breast Cancer ◽

Resistance Exercise ◽

Cancer Survivors ◽

Repeated Measures ◽

Breast Cancer Survivors ◽

Exercise Intervention ◽

Care Group ◽

Post Exercise ◽

Increased Risk ◽

Hispanic White

AbstractMOTS-c is a mitochondrial derived peptide with exercise mimetic activity that elicits beneficial effects on metabolism and exercise capacity. Furthermore, MOTS-c effects in humans are affected by race, potentially via ethnic-specific mtDNA variations. Women treated for breast cancer are at an increased risk for cardiovascular disease, diabetes and obesity, due to side effects of cancer-treatments. We conducted a secondary analysis of the effects of a 16-week aerobic and resistance exercise intervention on MOTS-c in Hispanic and Non-Hispanic White breast cancer survivors (BCS). BCS (Stage I–III) were randomized to exercise or standard care. The intervention promoted aerobic and resistance exercise for 16 weeks. MOTS-c was analyzed in fasting plasma using an in-house ELISA. Within and between group differences were assessed by paired t-test and repeated measures ANOVA. Pearson’s correlation was computed to assess the association between MOTS-c and metabolic biomarkers at baseline and post-exercise. Twenty-five Hispanic-BCS and 24 non-Hispanic White BCS were included. Hispanic BCS were younger, of greater adiposity, had higher stage cancers, and had worse metabolic profiles at baseline compared to non-Hispanic White BCS (p < 0.001). Post-exercise, MOTS-c levels significantly increased when compared to baseline and the usual care group among non-Hispanic White BCS (p < 0.01) but not among Hispanic breast cancer survivors (p > 0.01). Post-exercise levels of MOTS-c among non-Hispanic White BCS were significantly associated with reductions in fat mass, body weight, HOMA-IR, CRP, and an increase in lean mass (p < 0.01). A 16-week aerobic and resistance intervention increased MOTS-c levels among non-Hispanic White BCS. Trial registration: This trial is registered on ClinicalTrials.gov: NCT01140282 as of June 9, 2010. https://clinicaltrials.gov/ct2/show/NCT01140282.

Download Full-text

Alterations in Skeletal Muscle Repair in Young Adults with Type 1 Diabetes Mellitus

AJP Cell Physiology ◽

10.1152/ajpcell.00322.2021 ◽

2021 ◽

Author(s):

Athan G. Dial ◽

Grace K. Grafham ◽

Cynthia MF. Monaco ◽

Jennifer Voth ◽

Linda Brandt ◽

...

Keyword(s):

Electron Microscopy ◽

Skeletal Muscle ◽

Type 1 Diabetes ◽

Young Adults ◽

Gene Networks ◽

Vastus Lateralis ◽

Post Exercise ◽

Ultrastructural Damage ◽

The Impact

Though preclinical models of type 1 diabetes (T1D) exhibit impaired muscle regeneration, this has yet to be investigated in humans with T1D. Here we investigated the impact of damaging exercise (eccentric quadriceps contractions) in eighteen physically-active young adults with and without T1D. Pre- and post-exercise (48h and 96h), participants provided blood samples, vastus lateralis biopsies and performed maximal voluntary quadriceps contractions (MVC). Skeletal muscle sarcolemmal integrity, extracellular matrix content (ECM), and satellite cell (SC) content/proliferation were assessed by immunofluorescence. Transmission electron microscopy was used to quantify ultrastructural damage. MVC was comparable between T1D and controls before exercise. Post-exercise, MVC was decreased in both groups, but T1D subjects exhibited moderately lower strength recovery at both 48h and 96h. Serum creatine kinase, an indicator of muscle damage, was moderately higher in T1D participants at rest, and exhibited a small elevation 96h post-exercise. T1D participants showed lower SC content at all timepoints and demonstrated a moderate delay in SC proliferation after exercise. A greater number of myofibers exhibited sarcolemmal damage (disrupted dystrophin) and increased ECM (laminin) content in participants with T1D despite no differences between groups in ultrastructural damage as assessed by electron microscopy. Finally, transcriptomic analyses revealed dysregulated gene networks involving RNA translation and mitochondrial respiration, providing potential explanations for previous observations of mitochondrial dysfunction in similar T1D cohorts. Our findings indicate that skeletal muscle in young adults with moderately-controlled T1D is altered after damaging exercise; suggesting that longer recovery times following intense exercise may be necessary.

Download Full-text

Transdermal delivery of carnosine into equine skeletal muscle

Comparative Exercise Physiology ◽

10.3920/cep200077 ◽

2021 ◽

pp. 1-6

Author(s):

B.P. Dieter ◽

C.J. Macias ◽

T.J. Sharpe ◽

B. Roberts ◽

M. Wille ◽

...

Keyword(s):

Skeletal Muscle ◽

Transdermal Delivery ◽

Repeated Measures ◽

Muscle Metabolism ◽

Enzyme Linked Immunosorbent Assay ◽

Time To Exhaustion ◽

Thoroughbred Racehorses ◽

Repeated Measures Analysis ◽

Main Effect ◽

Main Effects

The dipeptide carnosine consists of β-alanine and L-histidine. It plays a major role in skeletal muscle metabolism, especially as an intracellular buffer and antioxidant. Increasing intramuscular carnosine has been shown to improve recovery from exercise and increase anaerobic threshold and time-to-exhaustion. Dietary supplementation with carnosine does not effectively increase intramuscular carnosine due to the presence of carnosinase in the blood. However, an effective transdermal delivery process could expediently increase intramuscular concentrations of carnosine. This study’s objective was to examine the efficacy of a transdermal system for delivering carnosine into the skeletal muscle of horses, using a randomised, placebo controlled, crossover study. Carnosine plus a proprietary transdermal delivery agent or the agent alone (placebo) were applied to the middle gluteal muscles of 10 Thoroughbred racehorses, and muscle biopsies were taken before and 30, 60, and 120 min after application. Muscle carnosine concentration was measured using an enzyme-linked immunosorbent assay. A two-way repeated measures analysis of variance was used to test for the main effects of time and treatment (placebo or carnosine) as well as an interaction between time and treatment. Independent F-tests examined the change in intramuscular carnosine levels from baseline to each time point (30, 60, and 120 min). There was a significant main effect of treatment (P=0.004), no significant main effect for time (P=0.18), and a non-significant interaction of treatment with time (P=0.08). Mean intramuscular carnosine concentrations increased from baseline to 120 min. Compared to concentrations following placebo application, carnosine was greater by ~35% at 30 min (P=0.002) and ~46% after 60 min (P=0.044), but not at 120 min (P=0.20). The results indicated that intramuscular carnosine can be increased using a transdermal delivery system within 60 min of application which could have important implications for the health of horses, and their capacity to perform and recover from physical activity.

Download Full-text

The Impact of Virtual Physical Activity Interventions on Depression and Anxiety among College Students: Randomized Controlled Trial (Preprint)

10.2196/preprints.31839 ◽

2021 ◽

Author(s):

Andy Murray ◽

Michele Marenus ◽

Ana Cahuas ◽

Kathryn Friedman ◽

Haley Ottensoser ◽

...

Keyword(s):

College Students ◽

Resistance Exercise ◽

Interaction Effect ◽

Repeated Measures ◽

Exercise Intervention ◽

Controlled Trial ◽

Depression Symptoms ◽

Depression And Anxiety ◽

Main Effect ◽

The Impact

BACKGROUND Depression and anxiety are growing issues for college students, with both aerobic-resistance training and mindfulness-yoga exercises known to be effective in reducing symptoms and severity. However, no known research is available comparing these two depression and anxiety interventions simultaneously and in a virtual environment. OBJECTIVE This study aimed to determine the effects of a virtual aerobic-resistance exercise intervention (WeActive) and a virtual yoga-mindfulness mindfulness exercise intervention (WeMindful) on depression and anxiety symptoms in college students METHODS The participants were 78 college students who anonymously completed a Qualtrics survey including the Generalized Anxiety Disorder Scale (GAD-7) and the Major Depression Inventory (MDI) at baseline and the post-test. Participants were randomly assigned to either the WeActive or WeMindful group and underwent two 30-minute virtual aerobic-resistance exercise lessons or yoga-mindfulness lessons per week for eight weeks. RESULTS The results of ANCOVA with repeated measures indicated that, while not statistically significant, both groups showed a notable decrease in anxiety with a marginal significant main effect of time (F = 3.485, p = 0.066, η2 = 0.047) but no significant main effect of group and no significant interaction effect of time with group. The two intervention groups experienced a significant decrease in depression with the main effect of time (F = 3.892, p = 0.052, η2 = 0.052). There was no significant main effect of group or interaction effect of time with group for depression. CONCLUSIONS College students in both WeActive and WeMindful groups experienced a significant decrease in depression symptoms and a decrease, though not significant, in anxiety as well. The study suggests that virtual WeActive and WeMindful interventions are effective approaches to managing US college student depression and anxiety during a pandemic.

Download Full-text

Effect of increased serum 25(OH)D and calcium on structure and function of post-menopausal women: a pilot study

Archives of Osteoporosis ◽

10.1007/s11657-020-00814-4 ◽

2020 ◽

Vol 15 (1) ◽

Author(s):

H. J. Hillstrom ◽

R. Soeters ◽

M. Miranda ◽

S. I. Backus ◽

J. Hafer ◽

...

Keyword(s):

Skeletal Muscle ◽

Muscle Fatigue ◽

Repeated Measures ◽

Vastus Lateralis ◽

Structure And Function ◽

Muscle Size ◽

Menopausal Women ◽

Post Menopausal ◽

And Function

Abstract Summary The purpose was to determine if increasing serum 25(OH)D and calcium in postmenopausal women increased skeletal muscle size, strength, balance, and functional task performance while decreasing muscle fatigue. PCSA of the vastus lateralis increased and ascent of stairs time decreased after 6 months of increased serum 25(OH)D. Purpose The Institute of Medicine recommends ≥ 20 ng/ml of serum 25-hydroxyvitamin D [25(OH)D] for bone and overall health. Serum 25(OH)D levels have been associated with physical performance, postural sway, and falls. The purpose of this study was to determine if increasing postmenopausal women’s serum 25(OH)D levels from 20–30 ng/ml to 40–50 ng/ml improved skeletal muscle size, strength, balance, and functional performance while decreasing skeletal muscle fatigue. Methods Twenty-six post-menopausal women (60–85 years old) with baseline serum 25(OH)D levels between 20 and 30 ng/ml were recruited. Oral over-the-counter (OTC) vitamin D3 and calcium citrate were prescribed to increase subjects’ serum 25(OH)D to levels between 40 and 50 ng/ml, serum calcium levels above 9.2 mg/dl, and PTH levels below 60 pg/ml, which were confirmed at 6 and 12 weeks. Outcome measures assessed at baseline and 6 months included muscle physiological cross-sectional area (PCSA), muscle strength, postural balance, time to perform functional tasks, and muscle fatigue. Repeated measures comparisons between baseline and follow-up were performed. Results Nineteen subjects completed the study. One individual could not afford the time commitment for the repeated measures. Three individuals did not take their vitamin D as recommended. Two subjects were lost to follow-up (lack of interest), and one did not achieve targeted serum 25(OH)D. Vastus lateralis PCSA increased (p = 0.007) and ascent of stair time decreased (p = 0.042) after 6 months of increasing serum 25(OH)D levels from 20–30 ng/ml to 40–50 ng/ml. Isometric strength was unchanged. Anterior-posterior center of pressure (COP) excursion and COP path length decreased (p < 0.1) albeit non-significantly, suggesting balance may improve from increased serum 25(OH)D and calcium citrate levels. Conclusions Several measures of muscle structure and function were sensitive to elevated serum 25(OH)D and calcium levels indicating that further investigation of this phenomenon in post-menopausal women is warranted.

Download Full-text

Antioxidants Facilitate High–intensity Exercise IL–15 Expression in Skeletal Muscle

International Journal of Sports Medicine ◽

10.1055/a-0781-2527 ◽

2018 ◽

Vol 40 (01) ◽

pp. 16-22 ◽

Cited By ~ 2

Author(s):

Alberto Pérez-López ◽

Marcos Martin-Rincon ◽

Alfredo Santana ◽

Ismael Perez-Suarez ◽

Cecilia Dorado ◽

...

Keyword(s):

Skeletal Muscle ◽

Protein Expression ◽

High Intensity ◽

Human Skeletal Muscle ◽

Vastus Lateralis ◽

Acute Hypoxia ◽

High Intensity Exercise ◽

Oxygen Deficit ◽

Post Exercise ◽

Sprint Exercise

AbstractInterleukin (IL)-15 stimulates mitochondrial biogenesis, fat oxidation, glucose uptake and myogenesis in skeletal muscle. However, the mechanisms by which exercise triggers IL-15 expression remain to be elucidated in humans. This study aimed at determining whether high-intensity exercise and exercise-induced RONS stimulate IL-15/IL-15Rα expression and its signaling pathway (STAT3) in human skeletal muscle. Nine volunteers performed a 30-s Wingate test in normoxia and hypoxia (PIO2=75 mmHg), 2 h after placebo or antioxidant administration (α-lipoic acid, vitamin C and E) in a randomized double-blind design. Blood samples and muscle biopsies (vastus lateralis) were obtained before, immediately after, and 30 and 120 min post-exercise. Sprint exercise upregulated skeletal muscle IL-15 protein expression (ANOVA, P=0.05), an effect accentuated by antioxidant administration in hypoxia (ANOVA, P=0.022). In antioxidant conditions, the increased IL-15 expression at 120 min post-exercise (33%; P=0.017) was associated with the oxygen deficit caused by the sprint (r=–0.54; P=0.020); while, IL-15 and Tyr705-STAT3 AUCs were also related (r=0.50; P=0.036). Antioxidant administration promotes IL-15 protein expression in human skeletal muscle after sprint exercise, particularly in severe acute hypoxia. Therefore, during intense muscle contraction, a reduced PO2 and glycolytic rate, and possibly, an attenuated RONS generation may facilitate IL-15 production, accompanied by STAT3 activation, in a process that does not require AMPK phosphorylation.

Download Full-text

Carbohydrate-Induced Insulin Signaling Activates Focal Adhesion Kinase: A Nutrient and Mechanotransduction Crossroads

Nutrients ◽

10.3390/nu12103145 ◽

2020 ◽

Vol 12 (10) ◽

pp. 3145 ◽

Cited By ~ 1

Author(s):

Dylan T. Wilburn ◽

Steven B. Machek ◽

Thomas D. Cardaci ◽

Darryn S. Willoughby

Keyword(s):

Focal Adhesion Kinase ◽

Focal Adhesion ◽

Insulin Signaling ◽

Repeated Measures ◽

Vastus Lateralis ◽

Future Research ◽

Placebo Condition ◽

Carbohydrate Ingestion ◽

Post Exercise ◽

Repeated Measures Design

Research has suggested that nutrient, exercise, and metabolism-related proteins interact to regulate mammalian target of rapamycin complex one (mTOR) post-exercise and their interactions needs clarification. In a double-blind, cross-over, repeated measures design, ten participants completed four sets to failure at 70% of 1-repitition maximum (1-RM) with 45 s rest on angled leg press with or without pre-exercise maltodextrin (2 g/kg) after a 3 h fast. Vastus lateralis biopsies were collected at baseline before supplementation and 1 h post-exercise to analyze Focal Adhesion Kinase (FAK), ribosomal protein S6 kinase beta-1 (p70S6K), insulin receptor substrate 1 (IRS-1), phosphatidylinositol 3-kinase (PI3K), and 5′ AMP-activated protein kinase (AMPK) activation. FAK and IRS-1 activity were only elevated 1 h post-exercise with carbohydrate ingestion (p < 0.05). PI3K and p70S6K activation were both elevated after exercise in both conditions (p < 0.05). However, AMPK activity did not change from baseline in both conditions (p > 0.05). We conclude that FAK does not induce mTOR activation through PI3K crosstalk in response to exercise alone. In addition, FAK may not be regulated by AMPK catalytic activity, but this needs further research. Interestingly, carbohydrate-induced insulin signaling appears to activate FAK at the level of IRS-1 but did not enhance mTOR activity 1 h post-exercise greater than the placebo condition. Future research should investigate these interactions under different conditions and within different time frames to clearly understand the interactions between these signaling molecules.

Download Full-text

The Combination of Fasting, Acute Resistance Exercise, and Protein Ingestion Led to Different Responses of Autophagy Markers in Gastrocnemius and Liver Samples

Nutrients ◽

10.3390/nu12030641 ◽

2020 ◽

Vol 12 (3) ◽

pp. 641 ◽

Cited By ~ 1

Author(s):

Ana P. Pinto ◽

Tales S. Vieira ◽

Bruno B. Marafon ◽

Gabriela Batitucci ◽

Elisa M. B. Cabrera ◽

...

Keyword(s):

Skeletal Muscle ◽

Physical Exercise ◽

Resistance Exercise ◽

Whey Protein ◽

Serum Levels ◽

Performance Outcomes ◽

Protein Ingestion ◽

Autophagy Pathway ◽

And Performance ◽

Exercise Stimulus

The present study verified the responses of proteins related to the autophagy pathway after 10 h of fast with resistance exercise and protein ingestion in skeletal muscle and liver samples. The rats were distributed into five experimental groups: control (CT; sedentary and without gavage after fast), exercise immediately (EXE-imm; after fast, rats were submitted to the resistance protocol and received water by gavage immediately after exercise), exercise after 1 h (EXE-1h; after fast, rats were submitted to the resistance protocol and received water by gavage 1 h after exercise), exercise and supplementation immediately after exercise (EXE/Suppl-imm; after fast, rats were submitted to the resistance protocol and received a mix of casein: whey protein 1:1 (w/w) by gavage immediately after exercise), exercise and supplementation 1 h after exercise (EXE/Suppl-1h; after fast, rats were submitted to the resistance protocol and received a mix of casein: whey protein 1:1 (w/w) by gavage 1 h after exercise). In summary, the current findings show that the combination of fasting, acute resistance exercise, and protein blend ingestion (immediately or 1 h after the exercise stimulus) increased the serum levels of leucine, insulin, and glucose, as well as the autophagy protein contents in skeletal muscle, but decreased other proteins related to the autophagic pathway in the liver. These results deserve further mechanistic investigations since athletes are combining fasting with physical exercise to enhance health and performance outcomes.

Download Full-text