Author(s): SEILER, H.L., FOSSTVEIT, S.H., FERON, J., JOYCE, K.E., SEGAERT, K., LUCAS, S.J.E., BERNTSEN, S., Institution: UNIVERSITY OF AGDER, Country: NORWAY, Abstract-ID: 1326

INTRODUCTION:
High-intensity interval training (HIIT) is a training method that is generally well-tolerated and feasible in older adults1 and has been shown to lead to improvements in physical, mental, and overall health-related quality of life (HRQOL)2, as well as having a favourable effect on physical function (PF)3. In clinical populations, PF and HRQOL are strongly linked4. However, there has been less focus on the relationship between changes in these outcomes in non-clinical older populations. Moreover, the effectiveness of HIIT under free-living conditions as part of public health strategy has not been adequately investigated5. Therefore, the aim of the present study was to investigate the effect of a 6-month homebased HIIT programme in older adults on PF and HRQOL and determine whether there were associations between training-induced changes in these variables.
METHODS:
Healthy older adults (n=233, 60-84 yrs, 54% female) from Norway and the UK were randomized to a HIIT group (67.6±5.9yr, mean±SD), or a non-exercising control group (67.0±5.2yr, mean±SD). The training was carried out as a 6-month triweekly HIIT intervention. PF was calculated as a composite Z-score (PF Z-score) based on: Grip strength, 30-sec-chair-stand, Chair-sit-and-reach, Back scratch, Timed-up-and-go, and One-leg standing. HRQOL was assessed by the Short Form health survey questionnaire (SF-12), with an explicit focus on HRQOL-general, -physical- and mental health.
General linear regression models (GLMs) assessed between-group differences in post-intervention PF Z-score, HRQOL-general, -physical- and mental health, with baseline values, age, sex and country as covariates, and group as a fixed factor. For associations between changes in PF and HRQOL within the HIIT group, GLMs were used, with age, sex, and country as covariates. Alpha level of 5% was chosen for statistical significance, with 95% CI presented.

RESULTS:
Significant between-group differences post-intervention were observed for PF Z-score (β=0.26, [0.16;0.36]), HRQOL-general health (β=0.76, [0.29;1.23]), and HRQOL-physical health (β=3.05, [0.34;5.77]), but not for HRQOL-mental health.
No associations were observed between absolute changes in PF Z-score and HRQOL-general health (β=-0.80, [-1.83;0.23]), and PF Z-score and HRQOL-physical health (β =-1.85, [-8.52;4.83]).


CONCLUSION:
These findings indicate that a non-clinical older population can improve their physical function through a 6-month home-based HIIT intervention, in addition to making improvements in HRQOL, although no associations were observed between these variables. Nevertheless, the findings highlight the potential role of HIIT as a valuable component of public health strategies for older adults.

REFERENCES:
1.Marriott et al., Sports Medicine – Open, 2021
2.Griffiths et al., Journal of Public Health, 2024
3.Stern et al., Sports Medicine – Open, 2023
4. Sunde et al., European Geriatric Medicine, 2021
5.Gray et al., British Journal of Sports Medicine, 2016