Background European guidelines have been introduced to screen masters and leisure athletes prior to participation in moderate- to high-intensity exercise, with the purpose of identifying the high risk athlete who should undergo a medical assessment. However, these guidelines have not been tested in large community based cycling races.

Objective To determine the prevalence of cyclists who would require a full medical assessment before participating in a community based mass participation cycling race using current European guidelines.

Design Cross-sectional study.

Setting 2016 Cape Town Cycle Tour (109 km).

Participants 22 650 cyclists.

Assessment All 37 425 race entrants were required to complete an online pre-race medical questionnaire (containing all the elements in the screening guidelines), and 22 650 (60.3%) gave consent that the information could be used for research purposes.

Main Outcome Measurements Prevalence (%) of risk factors that would require cyclists to undergo a full medical assessment before moderate- to high-intensity sports participation.

Results More than 35% cyclists would require a full medical assessment prior to participation. Risk factors for cardiovascular disease (CVD) were present in 24% of cyclists and 4% reported existing cardiac disease. The prevalence of chronic diseases in other organ systems was as follows: respiratory (14%), gastrointestinal (6%), nervous system (4%), metabolic/hormonal (4%), and urinary tract (4%). The prevalence of other possible risk factors for medical complications were, allergies (17%), chronic prescription medication use (29%), and use of acute medication (including NSAID's) before or during races (10%).

Conclusions These data show that >35% of cyclists entering a community based mass participation cycling race would require a medical assessment prior to participation if current international guidelines are to be implemented. We suggest that further research is conducted to determine if screening guidelines predict medical complications. Once these data are available, pre-screening guidelines for medical assessments may have to be revised.