vΔ50 Race Walking: High Energetic Cost, Rapid VO₂max, and No Slow Component

Area of Science:

• Exercise Physiology
• Sports Science
• Biomechanics

Background:

• Race walking, an Olympic sport, differs significantly from running in energy cost and muscle fiber recruitment.
• The cardiorespiratory responses of elite race walkers during severe-intensity exercise are not well understood.

Purpose of the Study:

• To ascertain if exhaustive exercise at vΔ50 elicits maximal oxygen uptake (VO2max) in young elite race walkers.
• To compare the temporal and metabolic responses of this intense exercise in race walkers versus similarly trained runners.

Main Methods:

• Fourteen elite junior athletes (7 race walkers, 7 runners) underwent incremental and constant-velocity tests.
• Measurements included oxygen uptake (VO2), heart rate, blood lactate, and time to exhaustion at vΔ50 (approx. 94% of vVO2max).

Main Results:

• Race walkers achieved VO2max at vΔ50 with minimal VO2 slow component (SC), unlike runners who showed a significant SC.
• The energy cost (EC) was 16% higher in race walking compared to running (p < 0.01).

Conclusions:

• Elite race walkers reach VO2max at vΔ50 primarily due to high baseline oxygen cost, not a progressive VO2 SC, differing from runners.
• Discipline-specific physiological responses suggest race walking training should utilize walking-specific intensity thresholds.
• This preliminary study with a small sample size warrants further investigation with larger cohorts.