The decline of swimming performance with advancing age: A cross-sectional study

The aim of this cross-sectional study was to measure the swimming parameters-speed (V), stroke frequency (SF), and stroke length (SL)-in 162 male athletes aged 50-90 (divided into 7 age groups, from A to G) participating in the World Master Championships in the 200-m freestyle event, and to analyze the rates and magnitudes of their age-associated declines. The swimmers were video-recorded by 2 digital cameras during the competitions and the swimming parameters related to every 50-m section (lap) and to the entire race (average) subsequently measured or calculated. Lap V and SF decreased in the second and third quarter (11 and 4% on average) and increased (3% on average) in the fourth quarter of the race, whereas lap SL decreased from the first to the last 50-m section. Average V (m.s(-1)) decreased from 1.39 +/- 0.09 (group A) to 0.84 +/- 0.11 (group G); average SL (m) decreased from 2.10 +/- 0.20 (group A) to 1.78 +/- 0.19 (group G); and average SF (cycles.s(-1)) decreased from 0.67 +/- 0.06 (group A) to 0.47 +/- 0.04 (group G). One-way analysis of variance showed significant declines in average V, SL, and SIP (p < 0.01) across the 7 groups. The swimming parameters were normalized to the highest values (set equal to 100); thereafter, a linear regression curve was fitted and the regression equations calculated. Decline of SF was about 2.5 times steeper than that of SL. It was highlighted that (a) among the swimming parameters, SL is less affected by the ageing process; (b) SL decreased from group A through group C and thereafter tended to keep steady, whereas the trend for SIP was opposite. The results have the potential to give master swimmers and their coaches useful information for training program design.