Effects of Protein and NAC Co-ingestion on Skeletal Muscle Recovery
ConditionAseptic Muscle Injury
Trial statusRecruiting
Trial phaseNot applicable
Trial typeInterventional
Biological sexMale
Age18-27
SponsorUniversity of Thessaly
About this trial
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.
Eligibility criteria
This trial accepts healthy volunteersQualifiers
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.
Disqualifiers
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.
Trial design
Design model
Parallel
Treatments tested in this trial
Placebo
Dietary supplementParticipants 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).
NAC
Dietary supplementParticipants 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 + Whey Protein
Dietary supplementParticipants 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).
Treatment groups
30 Participants
are divided into 3 treatment groupsGroup A: PlaceboPlacebo comparator 1 intervention
Group B: NACExperimental treatment 1 intervention
Group C: PRoNACExperimental treatment 1 intervention
Trial outcomes
Primary outcomes
1
Change in maximal voluntary isometric muscle contraction.
Maximal voluntary isometric muscle contraction will be assessed on an isokinetic dynamometer.
Time frame
Before exercise and at 1-, 2-, 3-, 24-, 48- and 72-hours post-exercise.2
Change in countermovement jump height.
Countermovement jump height will be assessed by using the Optojump Next system.
Time frame
Before exercise and at 1-, 2-, 3-, 24-, 48- and 72-hours post-exercise.3
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.
Time frame
Before exercise and at 1-, 2-, 3-, 24-, 48- and 72-hours post-exercise.4
Change in reduced glutathione content.
Reduced glutathione content in blood erythrocytes will be assessed using spectrophometric method.
Time frame
Before exercise and at 24-, 48- and 72-hours post-exercise.Secondary outcomes
1
Participants' lean body mass
Lean body mass (kg) will be assessed using dual-energy X-ray absorptiometry (DXA) instrumentation.
Time frame
At baseline.2
Participants' daily physical activity-related energy expenditure.
Physical activity-related energy expenditure (kcal/day) will be assessed using accelerometers.
Time frame
At baseline.3
Participants daily dietary intake.
Daily dietary intake composition (total kcal/day, gr of protein, gr of CHO and gr of fat intake/day, gr/mg of micronutrient intake/day) will be monitored using 24-h dietary recalls that will be analyzed by a trained dietitian using a dietary analysis software.
Time frame
At baseline.4
Participants' resting metabolic rate.
Resting metabolic rate will be assessed using indirect calorimetry.
Time frame
At baseline.Sponsors and contacts
Click on the lead sponsor to view all of their trials.
Source ClinicalTrials.gov