Author(s): OLSSON, C., TORELL, A., ANDERSSON, Å., HAGLUND, E., Institution: HALMSTAD UNIVERSITY , Country: SWEDEN, Abstract-ID: 2401

INTRODUCTION:
Physical exercise is an important treatment for individuals with the rheumatic disease axial spondyloarthritis (axSpA). Studies have found that high intensity interval training (HIIT) has positive effects on symptoms and risk factors without exacerbating disease activity(1). However, compliance tends to decrease over time, and long-term supervised training is costly. More knowledge is needed on how to tailor self-managed exercise programs for habitual exercise and improved health. The aim was to study if 12 wks of self-managed HIIT with digital support improved aerobic capacity, strength, body composition, disease activity, and health status differently compared to self-managed moderate intensity training done as usual in an axSpA control group.
METHODS:
Thirty-two individuals (16 women), with medically stable axSpA were recruited and randomized to a HIIT intervention group (HIG) or a control group (CTL). HIG completed 3 training sessions/wk where two had to be HIIT (e.g. 4x4 min) in self-selected activities. HIIT was individually tailored and monitored by a fitness watch and included digital support if needed 1/wk. The CTL also used fitness watches and were instructed to exercise as usual (fulfilled WHO recommendations). Assessments were done at baseline and after 12 wks including blood pressure (BP), aerobic capacity (VO2max), grip strength (kg), body mass (kg) and visceral fat (cm2). Self-reported disease activity (BASDAI), physical function (BASFI) and health status (EQ5D) were also measured. Data are presented as mean ± SD, significance level at p<0.05. Statistics included a 2 (group; HIG*CTL) by 2 (time; PRE*POST) repeated measures analysis of variance and when main effects or interactions were significant (p<0.05) t-tests were used as post-hoc analyses.
RESULTS:
Thirty people (age 46 ± 11 years) completed the training intervention. No differences were present between HIG (n=15) and CTL (n=15) at baseline for the studied variables. After 12 wks, both groups lowered their diastolic BP (HIG from 84 to 77 mmHg, p<0.01; CTL from 84 to 79 mmHg p<0.01). Bodyweight did not change but HIG showed a trend that visceral fat decreased (p=0.08), whereas CTL was unchanged (p=0.85). Moreover, both groups significantly increased their cardiac capacity in absolute VO2max (HIG 0.6±0.2 l/min, p<0.01; CTL 0.2±0.2 l/min, p<0.01) but only HIG increased their relative VO2max (9.0 ± 3.5 ml/kg/min, p<0.01). No change (p>0.05) was found in grip strength, health status, physical function or disease activity.
CONCLUSION:
After 12 wks of an ongoing RCT comparing self-managed HIIT with moderate training as usual in individuals with axSpA showed that both groups improved DBP and VO2max. HIIT did not seem to affect disease activity, physical function or health status compared to CTL. This indicates that HIIT is a safe form of exercise and both HIIT and moderate intensity training have a good effect on aerobic capacity in axSpA.
Reference: Sveaas SH, et al. Br J Sports Med, 2020. 54(5):292.