Acute Cardiovascular and Neuromuscular Responses to Walking With Blood Flow Restriction (BFR) in Older Adults

Acute Cardiovascular and Neuromuscular Responses to Walking With Blood Flow Restriction in Older Adults: a Study Protocol for a Randomized Crossover Trial

The goal of this clinical trial is to explore how walking combined with different levels of partial blood flow restriction (BFR) affects cardiovascular, neuromuscular, and movement (kinematic) variables in older adults.

The main questions it aims to answer are:

Does walking with BFR increase internal effort, as shown by cardiovascular changes, and is this effect proportional to the level of restriction?

Does walking with BFR temporarily reduce neuromuscular control, and is this reduction greater at higher restriction levels?

Does walking with BFR change gait movement patterns?

This study uses a crossover design, meaning that each participant will complete all four conditions and serve as their own control.

Participants will:

Take part in walking sessions under four conditions with different levels of restriction: BFR40%, BFR80%, SHAM (0% BFR), and CON (without BFR).

Have their cardiovascular responses, muscle performance, and gait movement patterns measured.

Report their perceptions of the sessions, including Rate of Perceived Exertion (RPE), satisfaction, and possible side effects.

This innovative research project aims to explore the effect of the novel BFR technique, combined with walking, as a non-pharmacological strategy to prevent or reverse sarcopenia and thereby improve the quality of life in sedentary older adults. BFR involves the use of a specialized pneumatic cuff to restrict venous blood flow to a muscle while partially inhibiting arterial flow, and it can be applied either at rest or in combination with exercise.

The application of BFR combined with exercise has shown promise as a tool to induce favorable physiological effects at lower training doses, that is, at lower intensities (e.g., lower intensities or slower walking or running speeds), compared to active control groups. However, despite the promising benefits reported in some studies, comprehensive investigation of the cardiovascular and neuromuscular responses during BFR combined with walking remains a largely unexplored area, both in healthy participants and special populations. This knowledge gap is particularly relevant when considering the substantial benefits that older adults and individuals with mobility limitations could gain from BFR combined with walking, especially given their potential difficulty in adhering to the minimum exercise dosage requirements recommended by the World Health Organization

Inclusion Criteria:

• Aged between 60 and 90 years.

Exclusion Criteria:

• Being institutionalized.
• Peripheral vascular disease, defined by an ankle-brachial index (ABI) outside the normal range (0.9-1.4).
• Uncontrolled arterial hypertension (>180/110 mmHg).
• Any contraindication to exercise, based on self-reported medical history and PAR-Q+.