Circuit class therapy can provide a fitness training stimulus for adults with severe traumatic brain injury: a randomised trial within an observational study.

QUESTIONS Can circuit class therapy provide sufficient exercise dosage (at least 20 minutes at ≥ 50% heart rate reserve or total caloric expenditure ≥ 300 kilocalories) to induce a cardiorespiratory fitness effect in adults with traumatic brain injury? Can feedback from heart rate monitors influence exercise intensity? DESIGN Randomised controlled trial within an observational study. PARTICIPANTS Fifty-three people with severe traumatic brain injury, of whom 40 progressed into the trial. INTERVENTION All participants undertook circuit class therapy. Participants allocated to the experimental group received exercise intensity feedback from a heart rate monitor and the control group received no feedback. OUTCOME MEASURES Proportion of participants exercising at ≥ 50% heart rate reserve for at least 20 minutes or expending ≥ 300 kilocalories during circuit class therapy. The primary outcome measure for the trial was the time spent in the heart rate training zone (ie, at ≥ 50% heart rate reserve) during the intervention and re-assessment periods. RESULTS Circuit class therapy provided sufficient cardiorespiratory exercise dosage for 28% (95% CI 18 to 42) of the cohort according to the heart rate reserve criteria and 62% (95% CI 49 to 74) according to the caloric criteria. Feedback did not increase the time in the training zone during the intervention (mean difference 4.8 minutes, 95% CI -1.4 to 10.9) or re-assessment (1.9 minutes, -4.4 to 8.3) periods. CONCLUSION The low intensity, long duration structure of circuit class therapy can provide sufficient exercise dosage for a fitness training effect for 62% of people with traumatic brain injury. Feedback from heart rate monitors does not necessarily influence exercise intensity. TRIAL REGISTRATION ACTRN12607000522415.