High-Intensity Interval Training Has Sustainable Effects in Patients With Inflammatory Arthritis

Erna Lorenzini June 09, 2023

MILAN, Italy — 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

Kristine Norden, Center for Treatment of Rheumatic and Musculoskeletal Diseases, Norwegian National Advisory Unit on Rehabilitation in Rehumatology, Diakonhjemmet Hospital, Oslo, Norway, presented the late-breaking results of the ExeHeart trial at the European Alliance of Associations for Rheumatology (EULAR) 2023 Annual Meeting. The trial aimed to evaluate the short- and long-term effects of 12 weeks of supervised HIIT in patients with IJD.

Norden explained to Medscape Medical News, “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 postbaseline. 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 4×4-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 (VO₂ 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 VO₂ max (2.5 mL/kg/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 VO₂ max between the groups was maintained at 6 months (2.6 mL/kg/min; P < .01), with no notable disparities in pain and fatigue. A per-protocol analysis at 3 months demonstrated a difference in VO₂ max between the groups (3.2 mL/kg/min; P < .01).

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.

Long-lasting Effects

Christopher Edwards, MBBS, MD, honorary consultant rheumatologist, University Hospital Southampton NHS Foundation Trust Medicine, University of Southampton, England, was concerned about future maintenance of increased CRF. “I really wish we had data on these patients at 12 months as well, so we could see if the effects last even longer. Regarding intensity, there are clear indications that engaging in moderate and high-intensity workouts is more beneficial,” Norden said. “So, I would certainly recommend at least one high-intensity exercise session per week for those patients, while also incorporating lower and moderate-intensity exercises if desired. However, for individuals aiming to maximize their oxygen uptake, high-intensity exercise is considered the most effective approach.”

There is compelling evidence supporting the benefits of physical activity in improving disease activity among patients with IJD, making it a critical component of nonpharmacologic treatment. However, individuals with rheumatic and musculoskeletal conditions generally exhibit lower levels of physical activity compared with their healthy counterparts. Recognizing the importance of CVD prevention in patients with IJD, EULAR recommends routine CVD screening for individuals diagnosed with IJD.

European Alliance of Associations for Rheumatology (EULAR) 2023 Annual Meeting: Abstract LB007. Presented June 2, 2023.

Norden and coauthors report no relevant financial relationships.