TITLE: SEX DIFFERENCES IN PERFORMANCE IN UPPER AND LOWER BODY DOMINANT SPORTS

AUTHORS: Annabelle McLaren, Llion Roberts, Mark Osborne, Nicola Bullock, Clare Minahan 

AFFILIATIONS: 1.  Griffith Sports Science, Griffith University, Gold Coast, Australia 2. Paddle Australia, AIS Facility, Gold Coast, Australia 3. Australian Institute of Sport, Australian Sports Commission, Canberra, Australia

PURPOSE: Sex-related differences in athletic performance are reported to be on average 10% for lower-body dominant sports (e.g., cycling, running). Conversely, there is evidence to suggest that the sex-related differences in anaerobic power measured in the upper body are greater than 10% in untrained individuals. Moreover, when power output measured during sprint exercise is normalised to muscle mass, there is no difference in the lower body, but the sex-related difference remains in the upper body. This may be due to sex-related differences in upper-body muscle quality (i.e., muscle fibre type), neuromuscular function, and/or metabolism. However, it is not clear if this relationship holds true for elite athletes. If so, the sex-related differences observed between a lower-body dominant sport such as track sprint cycling should be smaller than that observed in an upper-body dominant sport such as sprint kayaking.

METHODS: Flatwater kayak and track cycling events were examined to explore the sex-related differences in performance in upper- and lower-body dominant sports. Publicly available data was used to calculate the percentage difference between sexes using the winning times at a pinnacle event, such as a World Championship or Olympics, from the past 10 years (2013-2023). 

RESULTS: The percentage difference between sexes in kayak events (200-500m) was between 11.98-14.31%. Conversely, in track cycling the sex difference in the team pursuit and individual sprint were 9.87% and 11.10% respectively. 

CONCLUSION: The sex-related difference in kayak sprinting is higher than in track sprint cycling. It is possible that in some highly anaerobic sports, the sex difference is emphasised in upper-body dominant sports due to the significantly lower proportion of type II muscle fibres in females in the upper body. As it has been reported that 80% of kayak performance is determined by the upper-body, this may explain the increase in sex-related differences in kayaking. However, there are also other possible explanations, including the relative novelty of female kayaking at the elite level compared to other sports where females have had more experience at elite competitions. Recommendations are that sex differences may be emphasised in the upper body and therefore should be considered when prescribing training programs and goal setting.