Resistive Training Combined With Nutritional Therapy After Stroke "REPS"

Recruiting

Phase N/A Results N/A

Trial Description

Stroke survivors experience severe muscle wasting during the chronic phase of recovery, with implications for strength, function and general health. Although resistive exercise training effectively combats this problem, it is unknown whether sub-optimal protein intake limits the observed gains in skeletal muscle growth. Skeletal muscle adaptations may occur when resistive training (RT) is combined with nutritional therapy in the form of post- exercise protein consumption. This study would be the first to directly compare RT+protein supplementation to RT+placebo (same calories as protein supplement) in those with chronic hemiparesis caused by stroke, providing evidence-based rationale for combination therapy in the clinical care of this population.

Detailed Description

The VA research team has played a prominent role in documenting the significant skeletal muscle atrophy that accompanies chronic hemiparesis after disabling stroke. Muscle volume is reduced by 24% in paretic vs. non-paretic legs, having significant implications for strength, function, fitness, metabolism and general health. The investigators' previous work establishes progressive, high-intensity resistive training (RT) as an effective rehabilitation strategy for older stroke survivors, producing thigh muscle hypertrophy on both the paretic and non-paretic sides. Protein supplementation can significantly augment gains in muscle mass after RT in healthy populations, but no experiments have yet been conducted in stroke. New preliminary data from the investigators' group indicates that stroke participants consume 20% less protein than the recommended daily amount for older individuals (0.80 vs. 1.0 g/kg/day) suggesting that relative gains in skeletal muscle could be significantly better in the presence of adequate protein intake. New data also indicates that leg muscle mass predicts resting metabolic rate (RMR) in stroke, implying that a combined nutrition and RT therapy aimed at maximizing muscle gains would translate into improved energy balance, a key factor in rehabilitation success. A better understanding of the true potential for aggressive RT interventions to address stroke-related atrophy and related problems for maximum benefit awaits clinical trials directly comparing RT with and without nutritional therapy. The investigators propose to conduct a 12-week randomized placebo controlled clinical trial comparing the effects of RT+ protein supplementation at 1.2 g/kg/day (RT+PRO) vs. RT+isocaloric placebo (RT+PLA) on body composition, hypertrophy, strength, functional mobility and energy expenditure in chronic stroke.

Conditions

Interventions

  • Placebo Drug
    Intervention Desc: This training is designed to target the major muscle groups of the leg. Resistance training will be completed through a combination of lower extremity machines and complemented by whole body exercises such as squatting. The lower extremity machines include leg press, leg extension, and leg curl.This group will drink a placebo beverage after each training session.
    ARM 1: Kind: Experimental
    Label: Resistive Training
    Description: Participants will drink a placebo beverage before and after each resistance training session.
  • Protein Other
    Intervention Desc: This training is designed to target the major muscle groups of the leg. Resistance training will be completed through a combination of lower extremity machines and complemented by whole body exercises such as squatting. The lower extremity machines include leg press, leg extension, and leg curl. This group will drink a beverage containing protein after each training session.
    ARM 1: Kind: Experimental
    Label: Resistive Training + Protein
    Description: Participants will drink 15 grams of whey protein before and after each resistance training session.

Trial Design

  • Allocation: Randomized
  • Masking: Double Blind (Subject, Investigator)
  • Purpose: Treatment
  • Endpoint: Efficacy Study
  • Intervention: Parallel Assignment

Outcomes

Type Measure Time Frame Safety Issue
Primary Change in thigh muscle area Measured at baseline and after the 3 month intervention No
Secondary Change in muscle quality (strength per unit muscle volume) Measured at baseline and after the 3 month intervention No
Secondary Change in functional mobility (6 min walk distance) Measured at baseline and after the 3 month intervention No
Secondary Change in myostatin mRNA level Measured at baseline and after the 3 month intervention No
Secondary Change in myostatin messenger RNA (mRNA) level Measured at baseline and after the 3 month intervention No

Sponsors