Since 2002, the Royal Air Force (RAF) have been working towards introducing Operational Fitness Test (OFT), previously referred to as Representative Service Tasks (RSTs), to ensure that personnel have the physical capabilities required to carry out core operational tasks whilst deployed. Ideally, the OFT will be administered to personnel on a regular basis and prior to deployment, but this may not be viable due to time constraints or restricted availability of equipment. Alternatively, it may be more feasible to administer gym-based tests and predict RST performance. PURPOSE: To develop prediction models for RST performance from gym based fitness tests and anthropometric measurements. METHOD: One hundred and thirty RAF personnel (45 female) performed the RSTs (single lift; sandbag carry; fire & manoeuvre; dig) and a battery of fitness tests, including strength tests (hand grip, long jump, bicep curl), fitness tests (Multi Stage Fitness Test (MSFT), press ups, sit ups, repetitive sprint test) and anthropometric measurements (height, mass, hip girth, body fat, neck girth). Multiple polynomial regression was used to predict RST performance. RESULTS: Participant physical characteristics were established from the gym tests (mean±SD: age 31.7 ± 9.4 yrs; height 174.0 ± 8.8 cm; mass 77.5 ± 12.5 kg; maximal oxygen uptake 41 ± 11 ml.kg.-1min−1). The highest correlations between the fitness tests and RSTs were moderate (r2 = 0.33 to 0.71). The table shows which tests provided the best predictive model.TableCONCLUSION: The models indicate that aerobic (MSFT) and anaerobic fitness (sprints), body size (body mass, height, neck), muscular strength (bicep isometric force) and age are predictive of RST performance. The models may be of use as a screening tool for operational readiness, providing an indication of the nature and volume of training needed. However, the moderately poor LOA suggest that the models are on the margins of usability to predict RST performance and cannot be used with a high degree of predictive accuracy on an individual basis. This work was sponsored by the UK Ministry of Defence (RAF).