Maintaining and improving muscle strength can positively affect an older adult's ability to perform activities of daily living and in turn could esult in greater physical independence and quality of life. Currently it is recommended that older adults perform bouts of high-load (HL) resistance exercise at 60-80% of their maximum strength. However, HL training may not be feasible or safe for individuals who are very weak, frail, arthritic, or in a diseased state. The overall purpose of this study is to directly compare he training adaptations and perceptions of an innovative resistance training program to the currently recommended HL training regimen in older adults. Resistance training at very light loads and volumes (~20-30% of maximum strength) coupled with a blood flow restriction (LLBFR) has resulted in increased muscle mass and strength in young and old individuals, and these improvements are of similar magnitude to that seen with traditional HL resistance exercise. This type of resistance exercise is regularly performed in Japan, where it is referred to as KAATSU (meaning literally: strength training "with the addition of pressure"). Yet KAATSU (henceforth referred to as LLBFR resistance exercise) remains an unfamiliar concept in the United States. There are a limited number of studies that have investigated the use of LLBFR training to increase muscle strength in the aging population, but it is unknown whether this exercise regimen has any impact on functional capacity or quality of life. Therefore, the specific purposes of this study are to determine 1) if LLBFR resistance training is as tolerable and feasible as HL resistance training in older adults;and 2) whether similar adaptations in muscle strength, functional capacity and quality of life in older adults are evident after HL resistance training and LLBFR resistance training. To answer these questions, 45 males and females over 65 years of age who are classified as "at risk of developing mobility limitations" will be studied. The subjects will be placed randomly into one of 3 groups: HL resistance training, LLBFR resistance training, and a control group. Subjects will undergo muscle strength testing, tests of physical functioning and qualitative interviews before, midway and after 12 weeks of resistance training on the upper legs. Establishing the efficacy and tolerance of LLBFR training programs in older adults at risk of mobility limitations would lay the groundwork for implementation of LLBFR resistance exercise in older and weaker adults that cannot engage in HL resistance training. Muscle weakness and subsequent disability and decreased quality of life could be attenuated in older adults if LLBFR exercise is shown to be an effective alternative to HL resistance training.
While high-load resistance training is often prescribed to combat muscle weakness by increasing muscle strength and size, this type of exercise may not be appropriate for all older adults, particularly those with joint discomfort. Resistance training t a low-load coupled with a moderate blood flow restriction may be a practical alternative. The proposed study aims to determine if these two training regimens have similar effects on older adults'muscle strength and size, their ability to perform everyday tasks (functional capacity), and their quality of life.