Reasons for performing study: Standardised exercise tests are used for fitness evaluation of sports horses. Standards are described for Thoroughbreds and Standardbreds; however, limited information is available forWarmbloods. Objectives: To establish normative standards of performance parameters and heart rate recovery (HRR) in Warmblood riding horses of different levels of fitness using a submaximal incremental exercise test (SIET) performed on a treadmill. Methods: ASIET was carried out with 29 healthy and treadmillaccustomed Warmbloods: eleven 3-day event horses (TDE) and 18 horses from the National Equestrian Centre (NEC) competing in amateur jumping and/or dressage events. After a warm-up phase, horses performed 2 stages at trot and 3–5 stages at gallop at 6% incline. The first stage lasted 120 s, all others 90 s. Velocity (V) and heart rate (HR) were measured continuously and blood lactate concentration (LAC) at the end of each exercise stage. V at HR 150 and 200 beats/min (V150, V200), V and HR at 2 and 4 mmol/l LAC (V2, V4 and HR2, HR4, respectively) were calculated and compared between discipline groups. For reference values, horses were divided on the basis of the V4-results in good (GP) and average performers (AP) (performance groups). Five minute passive HRR was compared between performance groups. Fifteen NEC horses were retested within 1–3 months. Groups were compared with t tests and P<0.05 considered significant. Results: Three-day event horses had higher V150, V2 and V4 values than NEC. GP had higher values in all performance parameters compared to AP. No differences were found between test and retest. GP mean recovery HR was different from that of AP from 120 s of recovery onwards. Conclusion: Treadmill SIETs are suitable to objectify aerobic capacity in Warmblood riding horses. Normative standards were assessed for well and averagely-trained horses. The results can be referred to when diagnosing patients with exercise intolerance.