To examine aerobic capacity and neuromuscular performance in physically active females with early or long-term rheumatoid arthritis (RA) and healthy women.
Twenty-three RA-patients (12 early RA patients (ERA). 11 long-term RA (LRA) and 12 healthy controls (HC) performed maximal aerobic oxygen uptake (VO2max), muscle force production. walking and jump tests.
The VO2max ranged between 23-27 ml x kg(-1) min(-1) and did not differ between the groups. Isometric grip strength was 25% (p = 0.017) and bilateral leg extension strength 19% (p = 0.031) lower in LRA patients compared to ERA. In LRA the explosive force (p = 0.023) and relaxation times (p = 0.025-0.032) of bilateral leg extension and vertical squat jump (p = 0.015) did not reach the level of HC or ERA. The trunk muscle forces did not differ between the groups.
The physically active females even with LRA could maintain their aerobic fitness comparable to that of age matched healthy subjects. However, the neuromuscular profile suggests that especially explosive strength characteristics of the leg extensors cannot be maintained at the normal level with habitual physical activities.