Auto-regulated Resistance-training for Improving Strength in Older Adults

Auto-regulated resistance training has emerged as a resistance training paradigm to individualize programming; however, it remains to be elucidated whether auto-regulated resistance training provides a greater benefit than traditional standardized resistance training on physiological adaptations and performance outcomes in older adults. Traditional resistance training involves prescription of intensity as a percentage of the maximal amount of weight an individual can lift (for example, a resistance of 70% of maximal strength is a weight equal to 70% of the maximal weight a person can lift one time. An individual with this prescription would lift this weight for a number of repetitions to failure; i.e. usually 8-10 repetitions). Auto-regulation can be done two ways: "Subjective" auto-regulation involves lifting a weight for a number of repetitions until the individual reaches a certain "rating of perceived exertion". The rating of perceived exertion is on a scale of 1-10, with 10 being the most difficult or maximal exertion. For example, if one was prescribed a rating of perceived exertion of 8 they would lift a weight for a given number of repetitions until they believed they were at an 8/10 on the scale and had 2 repetitions left before failing. "Objective" auto-regulation involves lifting a weight for a given number of repetitions until a predetermined velocity of lifting is reached. For example, once someone starts to get fatigued while performing repeated lifting, the velocity of lifting will slow down. Once they have reached a critical slow velocity, the exercise would be stopped. There is some evidence that auto-regulation improves muscular strength to a greater extent than traditional resistance training in healthy populations. The research design is a prospective randomized trial comparing three training protocols in 30 participants. Participants will be randomized into one of three groups (n = 10 each), with matching on baseline strength: traditional standardized, subjective auto-regulated, and objective auto-regulated. Training will be twice per week for 12 weeks. Measures include strength assessments, muscle size, and performance of functional tasks.