Stroke Rate and Arm Coordination Management in Swimming in A Double Paralympic Triathlete Champion.

The highest effective stroke rate identified from the S-SR relationship was 44 cycle·min⁻¹, corresponding to the athlete's preferred stroke rate in 800m freestyle competition.

• Determined from a test of 10 × 25m swims incremented in swimming speed
• The S-SR relationship was modelled to detect two regimes of functioning
• The preferred SR in 800m freestyle competition matched the laboratory-determined optimal SR of 44 cycle·min⁻¹
• This SR was identified as the most effective based on the breakpoint between two functioning regimes

The para triathlete struggled to perform high stroke rate conditions, which was associated with higher total energy expenditure.

• Test 2 consisted of 6 × 50m swims at the speed of the 800m freestyle using 6 different SR conditions
• Conditions included: spontaneous SR (SRs), SRs imposed by tempo trainer, SRs+3, SRs+6, SRs-3, and SRs-6 cycles·min⁻¹
• Total energy expenditure was computed from post-exercise oxygen uptake and blood lactate measurements
• Higher SR conditions (SRs+3 and SRs+6) were associated with greater total energy expenditure compared to spontaneous and lower SR conditions

The para triathlete naturally decreased stroke rate when unconstrained, suggesting a spontaneous tendency toward lower SR.

• When performing the 6 × 50m test, the athlete naturally decreased SR below the spontaneous SR
• This natural decrease occurred in the absence of imposed constraints
• The spontaneous SR reduction contrasted with the difficulty experienced when SR was artificially increased

The 2024 Paris Paralympic triathlon swimming course required adaptation of stroke mechanics due to varying current conditions (swimming with and against the current).

• The race context motivated the study of stroke rate and arm coordination flexibility
• Swimming with and against the current necessitated different mechanical adaptations
• The study aimed to determine the range and optimal SR and index of coordination (IdC) to inform race strategy

The S-SR and S-IdC relationships were modelled to detect two distinct regimes of functioning in the para triathlete's front crawl.

• Two front crawl tests were performed: 10 × 25m incremented in swimming speed and 6 × 50m at 800m freestyle speed
• The modelling approach identified a breakpoint between two regimes in both S-SR and S-IdC relationships
• The index of coordination (IdC) reflects the temporal relationship between arm stroke phases
• This dual-regime model was used to identify the most effective SR and IdC

It is advised to modulate stroke rate around the preferred stroke rate to optimise swimming efficiency under varying current conditions.

• Modulating SR away from the preferred SR (particularly increasing it) led to higher energy costs
• The preferred SR of 44 cycle·min⁻¹ represented the most efficient operating point
• This recommendation has practical implications for Paralympic triathlon race strategy when swimming with or against current