Modality-Specific Heart Rate Differences at Ventilatory Thresholds During Unified Ramp Testing

The purpose of this study was to investigate the heart rate bias between cycling and treadmill exercise at ventilatory thresholds. This was a randomized crossover trial involving 23 healthy participants. Each participant performed both cycling and treadmill exercise tests in a randomized order. The primary outcome was to determine the difference in heart rate response at the first and second ventilatory thresholds between the two exercise modalities. We hypothesized that there is a fixed bias in heart rate response, which may have implications for exercise prescription in clinical and rehabilitation settings.

Inclusion Criteria: 1. Age ≥ 20 years. 2. Familiarity with both cycling and treadmill exercise. 3. Negative response on the Physical Activity Readiness Questionnaire (PAR-Q). Exclusion Criteria: 1. History of cardiovascular, pulmonary, or metabolic disease. 2. Musculoskeletal injuries limiting exercise range of motion. 3. Use of medications known to affect heart rate or ventilation.