Peak Running Velocity or Critical Speed Under Field Conditions: Which Best Predicts 5-km Running Performance in Recreational Runners?

This study aimed to examine which variable, between the peak running velocity determined on the track field (V(peak_TF)) and critical speed (CS), is the best predictor of the 5-km running performance in recreational runners. Twenty-five males performed three tests to determine the V(peak_TF), CS, and 5-km running performance on the track field, with a minimal interval of 48 h between each test. The V(peak)(_TF) protocol started with a velocity of 8 km⋅h(–1), followed by an increase of 1 km⋅h(–1) every 3 min until volitional exhaustion, which was controlled by sound signals, with cones at every 25 m indicating when the participants were required to pass the cone’s position to maintain the required velocity. The participants performed three time trials (TTs) (1: 2,600 m; 2: 1,800 m; and 3: 1,000 m) on the same day, with a 30-min rest period to determine the CS through the combinations of three (CS(1),(2),(3)) and two TTs (CS(1),(2), CS(1),(3), and CS(2),(3)). The 5-km running performance time was recorded to determine the test duration, and the mean velocity (MV) was calculated. There was a significant difference observed between the V(peak_TF) and the MV 5-km running performance. However, no differences were found between the CS values and the MV 5-km running performance. A correlation was observed between the V(peak_TF) (R = −0.90), CS(1),(2),(3) (R = −0.95), CS(1),(3) (R = −0.95), and the 5-km running performance time. Linear regression indicated that the V(peak_TF) (R(2) = 0.82), CS(1),(2),(3) (R(2) = 0.90), and CS(1),(3) (R(2) = 0.90) significantly predicted the 5-km running performance time. The CS results showed a higher predictive power for the 5-km running performance, slightly better than the V(peak_TF). Also, CS(1),(2),(3) and the CS(1),(3) presented the highest predictive power for the 5-km running performance of recreational runners.