Effects of Protein and NAC Co-ingestion on Skeletal Muscle Recovery

NCT06367413 | Recruiting

• 1 other identifier: UTH-PRoNAC Study
• Study Type: interventional
• Target: 30
• Locations: 1 country
• Sites: 1

Brief Summary

Previous evidence suggests that though N-acetylcysteine (NAC) supplementation following eccentric exercise-induced muscle damage disrupts the skeletal muscle's repair and remodelling process at 8 days of recovery, it attenuates substantially the decline of skeletal muscle performance during the first 48 hours of recovery. The enhanced performance capacity during the first phase of recovery in response to NAC supplementation might be attributed to the altered redox status in skeletal muscle as a consequence of the NAC-mediated elevation of reduced glutathione (GSH) levels. The rise in GSH results in a redox-dependent attenuation of immune cell mobilisation and reduction of oxidative stress response, leading to a blunted rise of muscle damage and inflammatory markers during the first 2-3 days of recovery. However, following exercise-induced muscle damage, protein synthesis increases in skeletal muscle over the next 24-48 hours to support its repair process, and thus protein supplementation might accelerate the recovery process by enhancing the protein synthetic response. Therefore, the present study aims at investigating for first time the combined effect of NAC and whey protein supplementation on the short-term (during the first 72 hours) recovery process of skeletal muscle following damaging exercise (eccentric exercise) and compared it with the well-documented efficacy of NAC supplementation. The results of this study might be particularly useful for athletes, such as those in soccer and basketball, that participate in 3 games or intense training sessions during the same macrocycle with only 48-72 hours of recovery in-between.

Conditions

Aseptic Muscle Injury

Outcome Measures

Primary Outcomes (8)

• Change in maximal voluntary isometric muscle contraction.

  Maximal voluntary isometric muscle contraction will be assessed on an isokinetic dynamometer.

  Before exercise and at 1-, 2-, 3-, 24-, 48- and 72-hours post-exercise.

• Change in countermovement jump height.

  Countermovement jump height will be assessed by using the Optojump Next system.

  Before exercise and at 1-, 2-, 3-, 24-, 48- and 72-hours post-exercise.

• Change in delayed onset of muscle soreness (DOMS)

  DOMS of the knee extensors of the dominant limb will be evaluated by palpation of the relaxed muscle's belly and distal region with participants rating the perceived soreness on a visual analogue scale ranging from 1 to 10.

  Before exercise and at 1-, 2-, 3-, 24-, 48- and 72-hours post-exercise.

• Change in reduced glutathione content.

  Reduced glutathione content in blood erythrocytes will be assessed using spectrophometric method.

  Before exercise and at 24-, 48- and 72-hours post-exercise.

• Change in oxidized glutathione content.

  Oxidized glutathione content in blood erythrocytes will be assessed using spectrophometric method.

  Before exercise and at 24-, 48- and 72-hours post-exercise.

• Change in catalase activity.

  Catalase activity will be measured spectrophotometrically in red blood cells.

  Before exercise and at 24-, 48- and 72-hours post-exercise.

• Change in protein carbonyl concentration

  Protein carbonyl concentration will be measured spectrophotometrically in red blood cells.

  Before exercise and at 24-, 48- and 72-hours post-exercise.

• Change in myoglobin concentration in blood.

  Myoglobin concentration in blood will be assessed using an automatic biochemistry analyzer and commercially available kits.

  Before exercise and at 24-, 48- and 72-hours post-exercise.

Secondary Outcomes (8)

• Participants' lean body mass

  At baseline.

• Participants' daily physical activity-related energy expenditure.

  At baseline.

• Participants daily dietary intake.

  At baseline.

• Participants' resting metabolic rate.

  At baseline.

• Participants' cardiorespiratory fitness status.

  At baseline.

Study Arms (3)

Placebo

PLACEBO COMPARATOR

Participants in this arm will execute 150 eccentric muscle contractions an receive a placebo supplement consisted of carbohydrate (maltodextrin).

Dietary Supplement: Placebo

NAC

EXPERIMENTAL

Participants in this arm will execute 150 eccentric muscle contractions an receive a N-acetylcysteine supplement.

Dietary Supplement: NAC

PRoNAC

EXPERIMENTAL

Participants in this arm will execute 150 eccentric muscle contractions an receive a supplement consisted of N-acetylcysteine and whey protein.

Dietary Supplement: NAC + Whey Protein

Interventions

Placebo DIETARY_SUPPLEMENT

Participants will receive three servings of carbohydrate per day during the 4-day experimental period. In specific, they will be supplemented with 0.31 gr of maltodextrin per kg of body weight in the first two servings (at mid-morning and mid-afternoon supplements) and with 0.49 gr of maltodextrin per kg of body weight in the pre-sleep serving (1.1 gr maltodextrin/kg BW/day).

Placebo

NAC DIETARY_SUPPLEMENT

Participants will receive three servings of N-acetylcysteine per day during the 4-day experimental period. In specific, they will be supplemented with 13.33 mg of N-acetylcysteine per kg of body weight per serving (40 mg NAC/kg BW/day).

NAC

NAC + Whey Protein DIETARY_SUPPLEMENT

Participants will receive three servings of N-acetylcysteine + whey protein per day during the 4-day experimental period. In specific, they will be supplemented with 0.31 gr of whey protein and 13.33 mg of N-acetylcysteine per kg of body weight in the first two servings (at mid-morning and mid-afternoon supplements) and with 0.49 gr of whey protein and 13.33 mg of N-acetylcysteine per kg of body weight in the pre-sleep serving (1.1 gr Whey protein + 40 mg NAC /kg BW/day).

PRoNAC

Eligibility Criteria

• Age: 18 Years - 27 Years
• Sex: male
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64)

You may qualify if:

• Free of asthma, kidney disease, bleeding disorders, peptic ulcers.
• Free of musculoskeletal injuries and limitations.
• Abstain from dietary energy restriction.
• Do not use medication such as anti-inflammatory drugs, antibiotics, antihypertensive drugs or anticoagulants.
• Do not use dietary supplements such as protein, carbohydrate, antioxidants, vitamins etc.
• Free of N-acetylcysteine intolerance.
• Non-smokers.
• Abstain from alcohol throughout the study.

You may not qualify if:

• Presence of asthma, kidney disease, bleeding disorders, peptic ulcers.
• Musculoskeletal injuries and limitations.
• Dietary energy restriction.
• Use of anti-inflammatory drugs, antibiotics, antihypertensive drugs or anticoagulants.
• Use of dietary supplements such as protein, carbohydrate, antioxidants, vitamins etc.
• N-acetylcysteine intolerance.
• Smoking.
• Alcohol consumption during the study.

Sponsors & Collaborators

• University of Thessaly: lead

Study Sites (1)

Department of Physical Education and Sport Science, University of Thessaly

Trikala, Karies, 42100, Greece

RECRUITING

MeSH Terms

Interventions

Whey Proteins

Intervention Hierarchy (Ancestors)

Milk Proteins; Animal Proteins, Dietary; Dietary Proteins; Proteins; Amino Acids, Peptides, and Proteins; Whey; Milk; Dairy Products; Food; Diet, Food, and Nutrition; Physiological Phenomena; Food and Beverages

Study Officials

• Dimitrios Draganidis, PhD

  University of Thessaly, Department of Physical Education and Sport Science

  PRINCIPAL INVESTIGATOR

Central Study Contacts

Dimitrios Draganidis, PhD

CONTACT

+30 2431047078; ddraganidis@uth.gr

Ioannis G Fatouros, PhD

CONTACT

+302431047047; ifatouros@uth.gr

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: TRIPLE
• Who Masked: PARTICIPANT, INVESTIGATOR, OUTCOMES ASSESSOR
• Masking Details: Participants, outcomes assessor and the principal investigator will be blinded until the intervention and the outcomes' assessment is done.
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Assistant Professor

Model Details: A randomized, double-blind, placebo-controlled, parallel group model.

Study Record Dates

• First Submitted: April 7, 2024
• First Posted: April 16, 2024
• Study Start: April 8, 2024
• Primary Completion: June 30, 2025
• Study Completion: July 30, 2025
• Last Updated: June 4, 2025

Record last verified: 2025-01

Locations

GR (1)