Skeletal Muscle Damage, Exercise-induced Aseptic Inflammation, Skeletal Muscle Performance, Intracellular Signaling in Skeletal Muscle, Proteasome Activation
Conditions
Brief summary
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.
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.
Interventions
DIETARY_SUPPLEMENTMilk 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.
DIETARY_SUPPLEMENTPlacebo
500 mL drink that contained water (375 mL), sugar-free cordial (125 mL) and 2 g of low-calorie glucose/dextrose powder.
Sponsors
University of Thessaly
Study design
Allocation
RANDOMIZED
Intervention model
CROSSOVER
Primary purpose
BASIC_SCIENCE
Masking
DOUBLE (Subject, Investigator)
Eligibility
Sex/Gender
MALE
Age
18 Years to 30 Years
Healthy volunteers
Yes
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
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Change in protein expression level of proteasome subunits | 1h before exercise, 2 days post-exercise, 8 days post-exercise | Measurement of B1i, B2i, B5i, B5, B1, B2 and α7 |
| Change in cytokine concentration in plasma | 1h before exercise, 2h post-exercise, daily for 8 days post-exercise | Measurement of IL-1β, IL-4, IL-6, IL-8, IL-10, TNF-α |
| 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 | 1h before exercise, 2 days post-exercise, 8 days post-exercise | 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. |
| Change in proteasome activities in muscle | 1h before exercise, 2 days post-exercise, 8 days post-exercise | Measurement of LLVY, LSTR and LLE |
| Change in reduced glutathione in blood | 1h before exercise, 2h post-exercise, daily for 8 days post-exercise | Concentration of reduced glutathione in red blood cells |
| Change in protein carbonyls in serum | 1h before exercise, 2h post-exercise, daily for 8 days post-exercise | Concentration of protein carbonyls |
| Change in protein carbonyls in muscle | 1h before exercise, 2 days post-exercise, 8 days post-exercise | Protein carbonyl concentration in quadriceps skeletal muscle group |
| Change in thiobarbituric acid and reactive substances in serum | 1h before exercise, 2h post-exercise, daily for 8 days post-exercise | Thiobarbituric acid reactive substances concentration in serum |
| Change in oxidized glutathione in blood | 1h before exercise, 2h post-exercise, daily for 8 days post-exercise | Concentration of oxidized glutathione in red blood cells |
| Change in total antioxidant capacity in serum | 1h before exercise, 2h post-exercise, daily for 8 days post-exercise | Total antioxidant capacity in serum |
| Change in catalase activity in serum | 1h before exercise, 2h post-exercise, daily for 8 days post-exercise | Catalase activity in serum |
| 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 | — |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Change in muscle function of knee extensor and flexor muscle | 1h before exercise, 5 min post-exercise, 2h post-exercise, daily for 8 days post-exercise | Assessment of muscle peak and mean torque of knee extensors and flexors on an isokinetic dynamometer at 0, 90 and 180 degrees/sec |
| Body composition | One day before exercise | Assessment of percent (%) body mass |
| Maximal aerobic capacity | One day before exercise | Assessment of maximal oxygen consumption |
| Change in dietary intake profile | 1h before exercise, daily for 8 days post-exercise | Assessment of dietary intake with emphasis on protein consumption |
Countries
Greece
Outcome results
None listed