EFFECT OF AQUATIC HIGH-INTENSITY INTERVAL TRAINING AND RESISTIVE AQUATIC INTERVAL TRAINING ON RESTING ENERGY EXPENDITURE AND RESPIRATORY RATIO IN ADULTS

M.M.Y. Kwok¹, S.S.M. Ng¹, D.Y.L. Pang¹, D.C.K. Tang¹, G.C.C. Tan¹, B.C.L. So¹

¹The Hong Kong Polytechnic University, Rehabilitation Sciences, Hong Kong, China

Background: Aquatic High Intensity Interval Training (AHIIT) allows a lower weight bearing aerobic alternative to optimise physical training in an aquatic environment. With the physical properties of water drag, moving in water generates more resistance and thus necessitates greater energy expenditure. The characteristic of Resistive aquatic high-intensity interval training (RAHIIT) allows AHIIT to be applied by eliminating joint impact with a potential to improve metabolic rates. Resting Energy Expenditure (REE) and respiratory ratio (RR) were usedas the outcome measures to reflect the basal metabolism of subjects. Despite the gaining popularity of various forms of AHIIT, the effects of AHIIT or RAHIIT on metabolic responses remain unknown.

Purpose: Here we strive to
1) match the intensity of an optimal AHIIT and RAHIIT in the aquatic environment
2) compare the metabolic response in young healthy adults in a single session of AHIIT and RAHIIT.

Methods: Twelve healthy subjects (4 females, 8 males) performed a stationary running exercise at a matched exercise intensity determined by either an aquatic or aquatic resistive incremental test done prior the AHIIT and RAHIIT (10 x 1-min bouts of stationary running at 90% HRmax separated by 1-min active recovery). The incremental stages in terms of percentage of heart rate (HR), maximal oxygen uptake (%VO₂max), percentage of oxygen uptake reserve (%VO₂R), percentage of heart rate reserve (%HRR), and rate of perceived exertion (RPE) were examined between the mediums and the metabolic responses (resting energy expenditure and respiratory ratio) were evaluated. A paired t-test was used to compare the dependent variables and cadences if the data was normally distributed. The level of correlations between metabolic variables was checked by Pearson’s linear correlation.

Results: The matched intensity (HR, %HRmax %VO2max, %VO2R, %HRR, and RPE) between AHIIT and RAHIIT aquatic resistive incremental tests were comparable to each other. Mean resting energy expenditure (REE) (AHIIT: 10.9±2.95, RAHIIT: 10.83 ±3.69 P>0.01) and mean respiratory ratio (RR) (AHIIT: 0.93± 0.51, RAHIIT: 0.93±0.10 P>0.01) were comparable to each other in AHIIT and RAHIIT. No significant group differences were observed for perceptive responses on enjoyment, self-efficacy and muscle fatigue index.

Conclusions: Comparable results demonstrated by the aquatic and land incremental tests allows AHIIT and RAHIIT prescriptions precisely at the same domain. AHIIT and RAHIIT are comparable on REE and RR.

Implications: The findings of the proposed study can provide valuable insights regarding the application of AHIIT and RAHIIT. Both interventions could be a time-efficient and efficacious approach for health professionals when designing individualised programs targeted on metabolic outcomes. The unique physical properties of water allowed AHIIT and RAHIIT presented individuals with lower weight bearing ability an aerobic exercise.

Funding acknowledgements: N/A

Keywords:
Aquatic exercise
Resistive exercise
Metabolic responses

Topics:
Health promotion & wellbeing/healthy ageing/physical activity

Did this work require ethics approval? Yes

Institution: The Hong Kong Polytechnic University

Committee: The Hong Kong Polytechnic University

Ethics number: HSEARS20220204005