Ventilatory Efficiency and End-Tidal CO₂ Kinetics During Active Recovery Following VT₂-Referenced Intermittent...

Area of Science:

• Sports Science
• Exercise Physiology
• Cardiopulmonary Exercise Testing (CPET)

Background:

• Basketball performance relies on repeated high-intensity efforts with brief recovery periods.
• Conventional fitness tests may not accurately reflect the active recovery demands of stop-and-go sports like basketball.
• Understanding short active-recovery kinetics is crucial for assessing effort tolerance in basketball players.

Purpose of the Study:

• To apply a VT2-referenced progressive-intermittent treadmill protocol to evaluate effort tolerance in basketball players.
• To analyze 60-second active-recovery kinetics during a simulated basketball game scenario.
• To determine if phase-dependent recovery information complements traditional CPET outcomes.

Main Methods:

• A progressive-intermittent treadmill protocol was used, referencing the second ventilatory threshold (VT2).
• Participants performed high-speed bouts (120-180% of VT2-derived speed) interspersed with 60-second active recovery intervals.
• Physiological variables (VO2, VCO2, VE, PetCO2, HR, lactate) were measured during recovery periods, with linear regression applied to kinetics.

Main Results:

• The protocol successfully differentiated VO2 across successive high-intensity bouts (p = 0.0001).
• Peak performance indices correlated with phase-specific recovery slopes, particularly in early and mid-recovery.
• While lactate decreased over 8 minutes, its rate of change did not correlate with peak performance metrics.

Conclusions:

• The VT2-referenced progressive-intermittent protocol is feasible for basketball players.
• This protocol provides valuable phase-dependent recovery data that supplements conventional CPET results.
• The findings have potential applications for assessing and training basketball players in applied team settings.