Survival of the fittest? The scientific basis for the Royal Navy pre-joining fitness test.

The Royal Navy introduced a pre-joining fitness test to the selection procedures for RN Ratings from Summer 2003. The scientific basis for the test came from the present study to investigate if anthropometric and physical fitness measures predicted training failure. Fitness and anthropometric data from 1641 trainees were collected, together with their training outcome (i.e. pass or fail), during the period from September 2001 to March 2002. In addition, a retrospective interrogation of medical records identified those who reported any lower limb injuries. The overall rate of training attrition was 22%. Success in training was associated with: gender; age; physical fitness; and, in the case of females, Body Mass Index (BMI). The reported incidence of lower limb injury (LLI) was associated with: gender; physical fitness; and, for female trainees, BMI. The reported incidence of LLI was approximately 50% in the 'least-fit' female group compared to 10% in the 'most-fit' male group. 16% of females and 2% of males were considered 'unfit' (i.e. did not attain the prescribed run standards of 13 min 15 s and 11 min 13 s respectively). 3% of trainees were considered 'obese' (a BMI > 30 kg.m-2) whereas more than 25% were overweight (BMI > 25 kg.m-2). As a result of this work, selection candidates must now demonstrate a minimum standard of aerobic fitness prior to arrival at HMS Raleigh. The future impact of this selection measure on the reported incidence of lower limb injury and financial costs of training requires further investigation.