Measured UV Exposures of Ironman, Sprint and Olympic-Distance Triathlon Competitors

Nathan J Downs,Taryn Axelsen,Alfio V Parisi,Ben R Dexter,Peter W Schouten

doi:10.3390/atmos11050440

Abstract

Triathletes present an extreme case of modelled behaviour in outdoor sport that favours enhanced exposure to solar ultraviolet radiation. This research presents personal solar ultraviolet exposures, measured using all-weather polysulphone film dosimeters, to triathletes during the distinct swimming, cycling and running stages of competitive Sprint, Olympic and Ironman events conducted within Australia and New Zealand. Measurements of exposure are made for each triathlon stage using film dosimeters fixed at a single site to the headwear of competing triathletes. Exposures are expressed relative to the local ambient and as absolute calibrated erythemally effective values across a total of eight triathlon courses (two Ironman, one half Ironman, one Olympic-distance, and four Sprint events). Competitor exposure results during training are also presented. Exposures range from between 0.2 to 6.8 SED/h (SED: standard erythema dose) depending upon the time of year, the local time of each event and cloud conditions. Cycle stage exposures can exceed 20 SED and represent the highest exposure fraction of any triathlon (average = 32%). The next highest stage exposure occurred during the swim (average = 28%), followed by the run (average = 26%). During an Ironman, personal competitor exposures exceed 30 SED, making triathlon a sporting discipline with potentially the highest personal ultraviolet exposure risk.

Highlights

Triathlon is an endurance sport contested over three distinct event stages, beginning with a swimming stage generally held in open water, transitioning to a bicycle road race and concluding with an endurance run
Ambient UV index (UVI) range recorded during training and event stage times by ARPANSA radiometers are listed for days where data is available for radiometers located in Brisbane (Springfield, Bribie Island, Raby Bay, Robina) and Perth (Busselton)
This research has demonstrated that triathlon as a sporting discipline can present competitors with extreme UV exposure risk over each of the swim, cycle and running stages of an event

Summary

Introduction

Triathlon is an endurance sport contested over three distinct event stages, beginning with a swimming stage generally held in open water, transitioning to a bicycle road race and concluding with an endurance run. A typical Sprint-distance triathlon requires triathletes to complete an open water swim stage of 750 m (this may vary depending on the location and set up of the course), a 20 km cycle race and a run stage of approximately 5 km. The endurance form of triathlon, known as an Ironman event, requires both male and female competitors to complete a 3.9 km swim, a 180 km bicycle road race and a 42.2 km marathon-distance run, with the half Ironman being half of these distances. Due to their extended duration, Ironman events typically take an entire day to complete

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Conclusion