Muscle Damage
Conditions
Keywords
Exercise-induced muscle damage, Resistance exercise, Sex differences, Muscle soreness, Milk protein, Dietary protein
Brief summary
Purpose: To investigate the impact of milk protein ingestion on resistance exercise-induced muscle damage in untrained males and females. Rationale: Unaccustomed resistance exercise can cause muscle damage, presenting as muscle soreness and reduced muscle function - such as loss of strength, power, and flexibility - for several days after the exercise bout. Therefore, individuals may require longer recovery periods before performing another exercise bout, and their performance may be impaired. Further, muscle soreness may reduce exercise compliance, particularly in novice individuals. Over time, this may compromise the gains in muscle mass and strength achieved through exercise training. Therefore, strategies to reduce the severity of exercise-induced muscle damage and/or to enhance post-exercise recovery processes are advantageous for exercising individuals. One such strategy is the consumption of dietary protein before or after muscle-damaging exercise, which has shown to alleviate muscle soreness, improve blood markers of muscle damage, and reduce the decline in maximal force and flexibility. In particular, consuming 20-gram doses of milk protein in the days after resistance exercise can improve the recovery time of muscle soreness and maximum force, and also lower levels of damage markers in the blood. However, most studies have been conducted with male participants who are well-trained in resistance exercise. It has been suggested that males and females respond differently to muscle damage, and therefore, this research aims to provide a sex comparison in the muscle damage response to an acute bout of resistance exercise with or without milk protein feeding. Therefore, 40 healthy, young (18-35 years) adults (20 males, 20 females) will be recruited to participate in this randomised controlled trial. Maximal leg strength and body composition (by dual-energy X-ray absorptiometry; DXA) will be conducted at baseline. In females, all primary outcome measures will be obtained during the late follicular phase of the menstrual cycle. Participants will then be randomised to a protein (dairy yoghurt) or placebo (oat-based yoghurt) dietary condition. Three weeks later, participants will complete a high-intensity resistance exercise session on leg extension and leg curl machines to induce muscle damage. Various measures of muscle damage (blood biomarkers, muscle soreness, flexibility, and swelling) will be obtained before, immediately after, and 24, 48, 72, and 168 h after the exercise protocol. The maximal strength test will be repeated 72 and 168 h after the exercise. Participants will consume the protein or placebo yoghurt 4 times per day (every 3-4 hours) on the day of the exercise bout and the following 3 days. Participants' habitual activity and dietary intake will be monitored and controlled throughout the study period. Expected outcome: It is expected that the resistance exercise protocol will induce muscle damage, which will be attenuated with the ingestion of milk protein. It cannot be ascertained whether males and females will have the same responses to the exercise or to protein ingestion.
Interventions
OTHERResistance exercise
Acute leg-based resistance exercise bout performed at 80% 1RM (4 sets to volitional failure on leg extension and leg curl machines)
Sponsors
Durham University
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
BASIC_SCIENCE
Masking
TRIPLE (Subject, Investigator, Outcomes Assessor)
Eligibility
Sex/Gender
ALL
Age
18 Years to 35 Years
Healthy volunteers
Yes
Inclusion criteria
* BMI 18.5 - 25.0 kg/m2 * Untrained in resistance exercise * No known chronic disease or current acute illness * No current or recent (past 3 months) musculoskeletal injury * No frequent use (2x per week for past month) of non-steroidal anti-inflammatory drugs and compliant to abstain from use during experimental period * No recent or current engagement in massage or cryotherapy and compliant to abstain from use during experimental period * No current use of protein or antioxidant supplements * Are able to consume dairy products (i.e., not lactose-intolerant or vegan) * Females will be eumenorrheic (regular menstrual cycle) \>12 months * Absence of pregnancy and breast-feeding
Exclusion criteria
* Underweight * Overweight/obese * Resistance trained * Current or recent injury * Pregnancy or breast-feeding * Lactose intolerant * Unwilling to provide blood samples, perform resistance exercise, or abstain from use of NSAID's and protein supplementation (unless instructed as part of the research) * Unwilling to abstain from other forms of exercise during the experimental period
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Maximal Voluntary Contraction at baseline | Baseline | One-repetition maximum (1RM) test: leg extension and leg curl machines |
| Change from baseline Maximal Voluntary Contraction at 72-hours post-exercise | 72-hours after the exercise bout | One-repetition maximum (1RM) test: leg extension and leg curl machines |
| Change from baseline Maximal Voluntary Contraction at 168-hours post-exercise | 168-hours after the exercise bout | One-repetition maximum (1RM) test: leg extension and leg curl machines |
| Creatine kinase concentration at baseline | Immediately pre-exercise | Serum concentration of creatine kinase from venous blood sampling |
| Change from baseline in Creatine Kinase concentration immediately post-exercise | Immediately after the exercise bout | Serum concentration of creatine kinase from venous blood sampling |
| Change from baseline in Creatine Kinase concentration at 24-hours post-exercise | 24-hours after the exercise bout | Serum concentration of creatine kinase from venous blood sampling |
| Change from baseline in Creatine Kinase concentration at 48-hours post-exercise | 48-hours after the exercise bout | Serum concentration of creatine kinase from venous blood sampling |
| Change from baseline in Creatine Kinase concentration at 72-hours post-exercise | 72-hours after the exercise bout | Serum concentration of creatine kinase from venous blood sampling |
| Change from baseline in Creatine Kinase concentration at 168-hours post-exercise | 168-hours after the exercise bout | Serum concentration of creatine kinase from venous blood sampling |
| Interleukin-6 concentration at baseline | Immediately pre-exercise | Serum concentration of Interleukin-6 from venous blood sampling |
| Change from baseline in Interleukin-6 concentration immediately post-exercise | Immediately after the exercise bout | Serum concentration of Interleukin-6 from venous blood sampling |
| Change from baseline in Interleukin-6 concentration at 24-hours post-exercise | 24-hours after the exercise bout | Serum concentration of Interleukin-6 from venous blood sampling |
| Change from baseline in Interleukin-6 concentration at 48-hours post-exercise | 48-hours after the exercise bout | Serum concentration of Interleukin-6 from venous blood sampling |
| Change from baseline in Interleukin-6 concentration at 72-hours post-exercise | 72-hours after the exercise bout | Serum concentration of Interleukin-6 from venous blood sampling |
| Change from baseline in Interleukin-6 concentration at 168-hours post-exercise | 168-hours after the exercise bout | Serum concentration of Interleukin-6 from venous blood sampling |
| Muscle soreness (pressure algometry) at baseline | Immediately pre-exercise | Self-perceived rating of muscle soreness with use of pressure algometry |
| Change in muscle soreness (pressure algometry) immediately post-exercise | Immediately after the exercise bout | Self-perceived rating of muscle soreness with use of pressure algometry |
| Change in muscle soreness (pressure algometry) at 24-hours post-exercise | 24-hours after the exercise bout | Self-perceived rating of muscle soreness with use of pressure algometry |
| Change in muscle soreness (pressure algometry) at 48-hours post-exercise | 48-hours after the exercise bout | Self-perceived rating of muscle soreness with use of pressure algometry |
| Change in muscle soreness (pressure algometry) at 72-hours post-exercise | 72-hours after the exercise bout | Self-perceived rating of muscle soreness with use of pressure algometry |
| Change in muscle soreness (pressure algometry) at 168-hours post-exercise | 168-hours after the exercise bout | Self-perceived rating of muscle soreness with use of pressure algometry |
| Muscle soreness (VAS) at baseline | Immediately pre-exercise | Self-perceived rating of muscle soreness while performing a bodyweight squat with use of a visual analogue scale |
| Change in muscle soreness (VAS) immediately post-exercise | Immediately after the exercise bout | Self-perceived rating of muscle soreness while performing a bodyweight squat with use of a visual analogue scale |
| Change in muscle soreness (VAS) at 24-hours post-exercise | 24-hours after the exercise bout | Self-perceived rating of muscle soreness while performing a bodyweight squat with use of a visual analogue scale |
| Change in muscle soreness (VAS) at 48-hours post-exercise | 48-hours after the exercise bout | Self-perceived rating of muscle soreness while performing a bodyweight squat with use of a visual analogue scale |
| Change in muscle soreness (VAS) at 72-hours post-exercise | 72-hours after the exercise bout | Self-perceived rating of muscle soreness while performing a bodyweight squat with use of a visual analogue scale |
| Change in muscle soreness (VAS) at 168-hours post-exercise | 168-hours after the exercise bout | Self-perceived rating of muscle soreness while performing a bodyweight squat with use of a visual analogue scale |
| Range of motion at baseline | Immediately pre-exercise | Flexibility of the exercised limb as determined by goniometry |
| Change in range of motion immediately post-exercise | Immediately after the exercise bout | Flexibility of the exercised limb as determined by goniometry |
| Change in range of motion at 24-hours post-exercise | 24-hours after the exercise bout | Flexibility of the exercised limb as determined by goniometry |
| Change in range of motion at 48-hours post-exercise | 48-hours after the exercise bout | Flexibility of the exercised limb as determined by goniometry |
| Change in range of motion at 72-hours post-exercise | 72-hours after the exercise bout | Flexibility of the exercised limb as determined by goniometry |
| Change in range of motion at 168-hours post-exercise | 168-hours after the exercise bout | Flexibility of the exercised limb as determined by goniometry |
| Limb circumference at baseline | Immediately pre-exercise | Measure of leg circumference with use of standard anthropometric tape to indicate muscle swelling |
| Change in limb circumference immediately post-exercise | Immediately after the exercise bout | Measure of leg circumference with use of standard anthropometric tape to indicate muscle swelling |
| Change in limb circumference at 24-hours post-exercise | 24-hours after the exercise bout | Measure of leg circumference with use of standard anthropometric tape to indicate muscle swelling |
| Change in limb circumference at 48-hours post-exercise | 48-hours after the exercise bout | Measure of leg circumference with use of standard anthropometric tape to indicate muscle swelling |
| Change in limb circumference at 72-hours post-exercise | 72-hours after the exercise bout | Measure of leg circumference with use of standard anthropometric tape to indicate muscle swelling |
| Change in limb circumference at 168-hours post-exercise | 168-hours after the exercise bout | Measure of leg circumference with use of standard anthropometric tape to indicate muscle swelling |
Countries
United Kingdom
Contacts
Primary ContactAlice G Pearson
Backup ContactLindsay S Macnaughton
Outcome results
None listed