Supplemental Protein And Resistance Training Adaptations

Not Applicable

Completed

• Conditions: Hypertrophy
• Interventions: Dietary Supplement: Placebo beverage; Dietary Supplement: Protein-polyphenol beverage

• Registration Number: NCT03918395
• Lead Sponsor: University of Exeter

Brief Summary

Chronic resistance training has been shown to increase muscle cross-sectional area, volume and strength. Individuals participating in a resistance training program may wish to consume protein supplements to aid recovery and maximise adaptation. Furthermore, antioxidants have been shown to aid recovery from acute bouts of exercise. However, the effect of antioxidants combined with protein on long term-training adaptation is not fully understood.

This study will combine measures of muscle size, muscle strength and function, and the underlying changes in muscle metabolism in order to assess the effect of consuming a combined protein-antioxidant supplement during a 30 session resistance training program.

Detailed Description

Supplemental protein ingestion is an established method for augmenting gains in fat free mass, muscle strength and muscle cross sectional area following a period of resistance exercise training. In addition to protein, supplements high in polyphenols such as berry and pomegranate extract are believed to be an effective method of reducing soreness and facilitating recovery following a single bout of resistance exercise.

However, whilst polyphenols are shown to facilitate recovery from a single session of resistance exercise, their effect on adaptations to repeated bouts of resistance exercise are unknown. Asking this question will allow a detailed investigation of the mechanisms by which protein-polyphenol ingestion may affect adaptations to resistance exercise training when compared to a non protein or polyphenol containing placebo, which is an important yet underexplored area

Study Timeline

• Study Start: 2018-09-01
• Study First Submitted: 2019-04-16
• Study First Submitted QC: 2019-04-16
• Study First Posted: 2019-04-17
• Primary Completion: 2019-12-21
• Study Completion: 2019-12-21
• Status Verified: 2020-03
• Last Update Submitted: 2020-03-30
• Last Update Posted: 2020-03-31

Recruitment & Eligibility

• Status: COMPLETED
• Sex: All
• Target Recruitment: 32

Inclusion Criteria

• Male and Female
• 18 - 40 years of age
• Recreationally active

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Exclusion Criteria

• Any diagnosed metabolic impairment (e.g. type 1 or 2 Diabetes). Such impairments can affect skeletal muscle metabolism
• Any diagnosed cardiovascular disease or hypertension
• Use of nutritional supplements (e.g. protein, polyphenols, vitamins, antioxidants) as use of nutritional supplements during the study period may interfere with the physiological responses to the supplements of interest administered in this study.
• Habitual dietary protein intake <0.8 g/kg/day or >1.6 g/kg/day as calculated with a three day diet diary. Habitually low protein may impair adaptations to resistance exercise training and a habitually excessive protein intake may negate the benefit of protein supplementation.
• Current musculoskeletal injury that may impair exercise performance or may be exacerbated due to this studies exercise protocol.
• Resistance trained (participating in structured resistance exercise 3 or more times per week for >6 months), endurance trained (participating in structured endurance exercise for >6h per week for >6 months), or sedentary participants as these are not the populations of interest.
• Chronic use of anti-inflammatory medicines prior to the study and unwillingness to refrain from taking anti-inflammatory medications during the study as these medications may affect skeletal muscle metabolism and/or adaptation to exercise.
• Individuals who carry an epi-pen, or those with a diagnosed allergy or who believe that they have an allergy to milk or milk products, crustacean shellfish, tree nuts, or peanuts
• Individuals with a severe allergy to egg, fish, wheat or soy ingredients as the product is manufactured in a facility that contains these ingredients
• Individuals with non removable metallic implants (including heart pacemaker, cochlea implants, medication pumps, surgical clips, plates or screws) or claustrophobia

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Study & Design

• Study Type: INTERVENTIONAL
• Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
Placebo	Placebo beverage	Placebo beverage
Protein-Polyphenol supplement	Protein-polyphenol beverage	Protein-polyphenol beverage

Primary Outcome Measures

Name	Time	Method
Change in cross-sectional area of quadriceps muscle group	After 30 training sessions (approx. 10 weeks)	The cross-sectional area of the muscles comprising the thigh after 30 training sessions will be compared to pre-training values. This will be measured using MRI.

Secondary Outcome Measures

Name	Time	Method
Change in knee extensor isokinetic total work	After 30 training sessions (approx. 10 weeks)	Bilateral knee extensor isokinetic total work will be assessed before and after the training program by quantifying work completed over 30 isokinetic quadriceps contractions on an isokinetic dynamometer.
Perceived quadriceps muscle soreness:	After 30 training sessions (approx. 10 weeks)	Soreness will be assessed at the start of each training session using a validated visual analogue scale (VAS)
Change in maximal isokinetic peak torque	After 30 training sessions (approx. 10 weeks)	Knee extensor isokinetic peak torque over 3 repetitions will be assessed before and after the training program using an isokinetic dynamometer.
Change in muscle protein synthesis assessed using the stable isotope Deuterium Oxide	After 30 training sessions (approx. 10 weeks)	The enrichment of deuterated alanine (from the deuterium oxide heavy water stable isotope tracer) in vastus lateralis biopsy samples will be measured relative to the non-deuterated alanine. The change over 48 hours will be measured pre- and post-training to calculate a fractional synthesis rate (% day).
Change in quadriceps muscle group volume	After 30 training sessions (approx. 10 weeks)	The volume of the muscles comprising the thigh after 30 training sessions will be compared to pre-training values. This will be measured using MRI.
Change in maximal isometric peak torque	After 30 training sessions (approx. 10 weeks)	Knee extensor isometric peak torque will be assessed before and after the training program using an isokinetic dynamometer.

Trial Locations

Locations (1)

University of Exeter; 🇬🇧 Exeter, Devon, United Kingdom