Lifting light weights with blood flow restriction to improve muscular fitness and functional abilities in older people

This will be a two-armed RCT. Older people will be recruited to undertake a 12 week resistance training intervention, with the initial 4-weeks comprising low-load exercise (predominantly body-weight while participants learn exercise techniques) and the remaining 8 weeks including traditional moderate-load training (lifting weights equivalent to 8-12 repetition maximum). Participants will also be followed up at 4 weeks after the exercise intervention has concluded (i.e. at 16 weeks). Participants will be randomly allocated to one of two arms for the duration of the study: ARM 1 - Traditional resistance training (RT): During the initial 4-week phase of training, participants will lift light weights for lower-body-based exercises. This training phase will aim to teach appropriate technique for lower-body exercises (variations of squats, deadlifts, lunges and step-ups). Training will occur 3x per week at Murdoch University's exercise science laboratory, and will always be supervised directly by an accredited exercise physiologist with a PhD under review and 4+ yrs experience implementing exercise training for older adults. In the following 8 weeks, participants will use the same exercises from the initial 4-week phase, but they will now lift heavier weights following current recommendations from the American College of Sports Medicine. During this phase, training will occur under the same conditions as the introductory phase (directly supervised at Murdoch University, 3x per week). It is anticipated that all training sessions will last 30-60 minutes throughout the study. ARM 2 - Resistance training with blood flow restriction (RTBFR): The exercise interventions in this group will be identical to ARM 1, with the exception that the introductory 4-week phase of training will be performed with thin inflatable cuffs applied to the top of the thighs, and inflated to a sub-occlusive pressure during all training sessions. The actual pressure applied will be individualised for each participant as 60% of the pressure required to occlude blood flow at rest (i.e. the arterial occlusion pressure; AOP). The AOP will be determined individually for each participant in their initial training session via gradual cuff inflation whilst auscultating the posterior tibial artery with doppler ultrasound, to determine the pressure required for complete occlusion. Exercise adherence will be assessed for all participants in the research by an Accredited Exercise Physiologist who is running the training sessions. The total number of sessions completed, as well as the number of repetitions and weight lifted for each set, will be recorded to indicate adherence to the program and the training dose experienced.