Protein Supplementation and Skeletal Muscle Healing Process

Effects of Protein Supplementation on Skeletal Muscle Regeneration and Healing Process Following Exercise-induced Aseptic Injury

In this study the investigators utilized protein supplementation over an 8-day period following eccentric exercise-induced muscle damage in order to test the initial hypotheses : i) protein supplementation after exercise-induced muscle injury affects exercise-induced aseptic inflammation and muscle performance.

Study Overview

• Status: Completed
• Conditions: Skeletal Muscle Performance; Skeletal Muscle Damage; Exercise-induced Aseptic Inflammation; Intracellular Signaling in Skeletal Muscle; Proteasome Activation
• Intervention / Treatment: Dietary supplement: Milk protein isolate; Dietary supplement: Placebo

Detailed Description

The objective was to examine weather protein supplementation is able to affect the inflammatory response as well as recovery of muscle performance following an intense eccentric exercise protocol. In a double-blind, counterbalanced design, 14 men received either Placebo (PLA) or milk protein isolate (PRO) for 8 consecutive days following a single bout of exercise (300 eccentric contractions at 30 deg/sec). In both conditions, performance was assessed at baseline, immediately post-exercise, 2h post-exercise and daily for 8 consecutive days. Blood samples were collected at baseline, 2h post-exercise and daily for the remaining 8 days. Muscle biopsies from vastus lateralis were collected at baseline as well as at day 2 and day 8 of the post-exercise period.

• Study Type: Interventional
• Enrollment (Actual): 14
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Greece
  • Karies, Trikala, Greece, 42100
    • Exercise Biochemistry Laboratory, School of Physical Education & Sports Sciences, University of Thessaly

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 30 years (ADULT)
• Accepts Healthy Volunteers: Yes
• Genders Eligible for Study: Male

Description

Inclusion Criteria:

• a) recreationally trained as indicated by the maximal oxygen consumption levels (VO2max > 45 ml/kg/min), b) engaged in systematic exercise at least three times per week for > 12 months, c) non-smokers, d) abstained from any vigorous physical activity during the study, e) abstained from consumption of caffeine, alcohol, performance-enhancing or antioxidant supplements, and medications during the study.

Exclusion Criteria:

• a) a recent febrile illness, b) history of muscle lesion, c) lower limb trauma

Study Plan

How is the study designed?

Design Details

• Primary Purpose: BASIC_SCIENCE
• Allocation: RANDOMIZED
• Interventional Model: CROSSOVER
• Masking: DOUBLE

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
EXPERIMENTAL: Protein; Milk protein isolate supplementation: orally, 20g of protein immediately post-exercise and then 20g every 3h on 3 occasions (+3, +6, +9), on the exercise day. The remaining 8 days, 20g daily with breakfast.	Dietary supplement: Milk protein isolate; Milk protein isolate in a powder form consisted of 80% casein and 20% whey protein. 20g were diluted into 500 ml water. Placebo consisted of 365 ml water, 125 ml sugar-free cordial and 2g of low-calorie glucose/dextrose powder.
ACTIVE_COMPARATOR: Placebo; Placebo administration: orally 500 ml, immediately post-exercise as well as at +3, +6 and +9 hours, on the exercise day. The remaining 8 days, 500 ml daily with breakfast.	Dietary supplement: Placebo; 500 mL drink that contained water (375 mL), sugar-free cordial (125 mL) and 2 g of low-calorie glucose/dextrose powder.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in reduced glutathione in blood	Concentration of reduced glutathione in red blood cells	1h before exercise, 2h post-exercise, daily for 8 days post-exercise
Change in protein carbonyls in serum	Concentration of protein carbonyls	1h before exercise, 2h post-exercise, daily for 8 days post-exercise
Change in protein carbonyls in muscle	Protein carbonyl concentration in quadriceps skeletal muscle group	1h before exercise, 2 days post-exercise, 8 days post-exercise
Change in thiobarbituric acid and reactive substances in serum	Thiobarbituric acid reactive substances concentration in serum	1h before exercise, 2h post-exercise, daily for 8 days post-exercise
Change in oxidized glutathione in blood	Concentration of oxidized glutathione in red blood cells	1h before exercise, 2h post-exercise, daily for 8 days post-exercise
Change in total antioxidant capacity in serum	Total antioxidant capacity in serum	1h before exercise, 2h post-exercise, daily for 8 days post-exercise
Change in catalase activity in serum	Catalase activity in serum	1h before exercise, 2h post-exercise, daily for 8 days post-exercise
Change in creatine kinase activity in plasma		1h before exercise, 2h post-exercise, daily for 8 days post-exercise
Change in C-reactive protein in plasma		1h before exercise, 2h post-exercise, daily for 8 days post-exercise
Change in white blood cell count in blood		1h before exercise, 2h post-exercise, daily for 8 days post-exercise
Changes in volume and morphological complexity of immune cells		1h before exercise, 2h post-exercise, daily for 8 days post-exercise
Change in neutrophil count in blood		1h before exercise, 2h post-exercise, daily for 8 days post-exercise
Change in glucose concentration in blood		1h before exercise, 2h post-exercise, daily for 8 days post-exercise
Change in insulin concentration in blood		1h before exercise, 2h post-exercise, daily for 8 days post-exercise
Change in testosterone concentration in plasma		1h before exercise, 2h post-exercise, daily for 8 days post-exercise
Change in cytokine concentration in plasma	Measurement of IL-1β, IL-4, IL-6, IL-8, IL-10, TNF-α	1h before exercise, 2h post-exercise, daily for 8 days post-exercise
Change in adhesion molecule concentration in blood		1h before exercise, 2h post-exercise, daily for 8 days post-exercise
Change in intracellular signalling proteins in muscle	Measurement of phosphorylation levels of mammalian target of rapamycin (mTOR), ribosomal protein S6 (rpS6) and nuclear factor kB (NFkB), and protein expression levels of forkhead box protein O1 (FOXO1), HSP70, and parkin.	1h before exercise, 2 days post-exercise, 8 days post-exercise
Change in proteasome activities in muscle	Measurement of LLVY, LSTR and LLE	1h before exercise, 2 days post-exercise, 8 days post-exercise
Change in protein expression level of proteasome subunits	Measurement of B1i, B2i, B5i, B5, B1, B2 and α7	1h before exercise, 2 days post-exercise, 8 days post-exercise

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in muscle function of knee extensor and flexor muscle	Assessment of muscle peak and mean torque of knee extensors and flexors on an isokinetic dynamometer at 0, 90 and 180 degrees/sec	1h before exercise, 5 min post-exercise, 2h post-exercise, daily for 8 days post-exercise
Body composition	Assessment of percent (%) body mass	One day before exercise
Maximal aerobic capacity	Assessment of maximal oxygen consumption	One day before exercise
Change in dietary intake profile	Assessment of dietary intake with emphasis on protein consumption	1h before exercise, daily for 8 days post-exercise

Collaborators and Investigators

• Sponsor: University of Thessaly
• Investigators: Principal Investigator: IOANNIS G. FATOUROS, Ph.D., UNIVERSITY OF THESSALY, SCHOOL OF PHYSICAL EDUCATION & SPORTS SCIENCES

Study record dates

Study Major Dates

• Study Start: May 1, 2014
• Primary Completion (ACTUAL): February 1, 2016
• Study Completion (ACTUAL): July 1, 2016

Study Registration Dates

• First Submitted: June 24, 2016
• First Submitted That Met QC Criteria: June 24, 2016
• First Posted (ESTIMATE): June 28, 2016

Study Record Updates

• Last Update Posted (ESTIMATE): October 4, 2016
• Last Update Submitted That Met QC Criteria: October 3, 2016
• Last Verified: July 1, 2016

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Pathologic Processes; Inflammation; Molecular Mechanisms of Pharmacological Action; Chelating Agents; Sequestering Agents; Caseins
• Other Study ID Numbers: PROTEIN-MUSCLEINJURY-2014