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

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

Interventions

DIETARY_SUPPLEMENT

Placebo

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).

DIETARY_SUPPLEMENT

NAC

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).

DIETARY_SUPPLEMENT

NAC + Whey Protein

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).

Sponsors & Collaborators

• University of Thessaly

  lead OTHER

Principal Investigators

• Dimitrios Draganidis, PhD · University of Thessaly, Department of Physical Education and Sport Science

Study Design

Allocation

RANDOMIZED

Purpose

TREATMENT

Masking

TRIPLE

Model

PARALLEL

Eligibility

Min Age

18 Years

Max Age

27 Years

Sex

MALE

Healthy Volunteers

Yes

Timeline & Regulatory

Start

2024-04-08

Primary Completion

2025-06-30

Completion

2025-07-30

Countries

• Greece

Study Locations