Independent risk factors associated with a history of exercise associated muscle cramps (EAMC) among 21460 cycling race entrants (SAFER XXXVI) : a descriptive cross-sectional study

Abstract

BACKGROUND : There is limited research on cyclists with a history of exercise associated muscle cramps (hEAMC) defined as muscle cramping (painful, spontaneous, sustained spasm of a muscle) during or after cycling. OBJECTIVE : To determine the epidemiology, clinical characteristics, and risk factors associated with hEAMC in cyclists taking part in a mass participation cycling event. METHODS : 21,460 race entrants from the 2016 Cape Town Cycle Tour completed an online questionnaire, which is based on the guidelines for recreational exercise participation from the European Association of Cardiovascular Prevention and Rehabilitation [EACPR]. The main outcome measures were: the lifetime prevalence hEAMC (%; 95% confidence intervals), independent risk factors (adjusted for age and sex) associated with hEAMC (history of chronic disease, history of allergies, history of chronic medication use, history of medication use before and during race, history of cycling injuries, and cycling training/racing variables). Poisson regression was used to calculate the prevalence (%) of the variables of interest, with 95% confidence intervals. RESULTS : The retrospective lifetime prevalence of hEAMC was 30.51%. EAMC in cyclists affects mainly the quadriceps muscles and occurs in the 4th quarter during a race. Novel independent risk factors associated with an increased risk of hEAMC in cyclists were: increased number of years participating as a recreational cyclist (PR=1.03 per 5 years increase; p<0.0001), a higher chronic disease composite score (PR=1.36 times increased risk for every 2 additional chronic diseases; p<0.0001), a history of any allergies (PR=1.18; p<0.0001), medication use before or during event (PR=1.41; p<0.0001) a history of an acute (PR=1.30; p<0.0001) and gradual onset injury (PR=1.29; p<0.0001). CONCLUSION : Our study identified novel independent risk factors associated with a hEAMC. These results, in combination with other known risk factors, could assist future targeted prevention programmes and the management of EAMC in recreational cyclists.

HIGHLIGHTS • Older cyclists and males have a significantly higher lifetime prevalence of hEAMC. • EAMC in cyclists affects mainly the quadriceps muscles. • EAMC in cyclists occurs mainly in the 4th quarter during a race. • Risk factors for hEAMC: experience, chronic disease, allergies, medications, past injury.