High-intensity interval training has sustainable effects in patients with inflammatory arthritis

MILAN – High-intensity interval training (HIIT) has been shown to enhance cardiorespiratory fitness (CRF) and mitigate cardiovascular disease (CVD) risk factors in patients with inflammatory joint diseases (IJD) in a randomized trial. Notably, the positive response in CRF did not coincide with changes in pain or fatigue.

Kristine Norden, of the Center for Treatment of Rheumatic and Musculoskeletal Diseases, Norwegian National Advisory Unit on Rehabilitation in Rheumatology, Diakonhjemmet Hospital, Oslo, presented the late-breaking results of the ExeHeart trial at the annual European Congress of Rheumatology. The trial aimed to evaluate the short- and long-term effects of 12 weeks of supervised HIIT in patients with IJD.

^{Viktor Cap/Thinkstock}

Ms. Norden said in an interview that “HIIT is a feasible physiotherapeutic intervention with sustainable effects in patients with IJD. It does not exacerbate symptoms of IJD and can be implemented in primary care settings.”

The trial

The ExeHeart trial is a randomized controlled trial designed to assess the effects of HIIT on CRF, CVD risk, and disease activity in patients with IJD. The trial is a collaborative effort with patient research partners and aligns with patients’ requests for effective nonpharmacologic treatments. The outcomes being evaluated include CRF (primary outcome), CVD risk factors, anthropometric measures, disease activity, and patient-reported outcomes related to pain, fatigue, disease, physical activity, and exercise.

A total of 60 patients with IJD were recruited from the Preventive Cardio-Rheuma clinic at Diakonhjemmet. They were randomly assigned to receive either standard care (including relevant lifestyle advice and cardiopreventive medication) or standard care along with a 12-week HIIT intervention supervised by physiotherapists. Assessments were conducted at baseline, at 3 months (primary endpoint), and at 6 months post baseline. There was no supervised intervention between the 3- and 6-month time points.

The median age of the participants was 59 years, with 34 participants (57%) being women. The types of IJD among the participants included rheumatoid arthritis in 45%, spondyloarthritis in 32%, and psoriatic arthritis in 23%. Furthermore, 49 patients (82%) had a high risk for CVD.

The participants were divided into two groups: a control group (n = 30) and a HIIT group (n = 30). The HIIT group underwent a 12-week intervention consisting of twice-a-week supervised 4x4-minute HIIT sessions at 90%-95% of peak heart rate, alternated with moderate activity at 70%. The control group engaged in unsupervised moderate-intensity exercise sessions. The primary outcome measured was the change in CRF, assessed through peak oxygen uptake (VO_{2 max}) using a cardiopulmonary exercise test. Secondary outcomes – pain and fatigue – were evaluated using a questionnaire (Numeric Rating Scale 0-10, where 0 represents no pain or fatigue).

Following HIIT, a statistically significant difference was observed in VO_{2 max} (2.5 mL/kg per min; P < .01) in favor of the exercise group at 3 months, while no significant differences were found in pain and fatigue. This discrepancy in VO_{2 max} between the groups was maintained at 6 months (2.6 mL/kg per min; P < .01), with no notable disparities in pain and fatigue. A per-protocol analysis at 3 months demonstrated a difference in VO_{2 max} between the groups (3.2 mL/kg per min; P < .01).

Ms. Norden concluded that the clinical implications of these findings are significant, as increased CRF achieved through HIIT reflects an improvement in the body’s ability to deliver oxygen to working muscles. Consequently, this enhancement in CRF can lead to overall health improvements and a reduced risk for CVD.