Selective Changes in the Mechanical Capacities of Lower-Body Muscles After Cycle-Ergometer Sprint Training Against Heavy and Light Resistances.

Purpose: To explore the feasibility of the linear force-velocity (F-V) modeling approach to detect selective changes of F-V parameters (ie, maximum force [F], maximum velocity [V], F-V slope [a], and maximum power [P]) after a sprint-training program.

Methods: Twenty-seven men were randomly assigned to a heavy-load group (HLG), light-load group (LLG), or control group (CG). The training sessions (6 wk × 2 sessions/wk) comprised performing 8 maximal-effort sprints against either heavy (HLG) or light (LLG) resistances in leg cycle-ergometer exercise. Pre- and posttest consisted of the same task performed against 4 different resistances that enabled the determination of the F-V parameters through the application of the multiple-point method (4 resistances used for the F-V modeling) and the recently proposed 2-point method (only the 2 most distinctive resistances used).

Results: Both the multiple-point and the 2-point methods revealed high reliability (all coefficients of variation <5% and intraclass correlation coefficients >.80) while also being able to detect the group-specific training-related changes. Large increments of F, a, and P were observed in HLG compared with LLG and CG (effect size [ES] = 1.29-2.02). Moderate increments of V were observed in LLG compared with HLG and CG (ES = 0.87-1.15).

Conclusions: Short-term sprint training on a leg cycle ergometer induces specific changes in F-V parameters that can be accurately monitored by applying just 2 distinctive resistances during routine testing.