Effects of Two Six-week Exercise Prescriptions on Running Performance and Clinical Manifestations of Cardiometabolic Disease

Adequate exercise is a powerful stimulus for change in fitness and a preventive and therapeutic stimulus for lifestyle related diseases. However, optimal dosage methodologies for exercise prescription remain unclear. Objective: To determine differences in achieved exercise intensity and the performance and metabolic disease related outcomes of six weeks of run training prescribed either via heart rate (HR) or rating of perceived exertion (RPE). Design: Laboratory and field controlled trial. Participants were assigned into a heart rate training group (HRTG) and a RPE training group (RPETG) in a non-randomized, counter-balanced method controlling for baseline values. Methods: Forty males completed maximal graded exercise testing (GXT), anthropomorphic measurements, a 12 min run test, and a fasting blood draw before and after 6 weeks of run training. Intensity was prescribed at 45, 60, 75, and 90%VO2 reserve (VO2R) as a target HR or RPE. Only HRTG viewed HR during the session. Results: Mean %HRR (66±7, 62±9 %HRR) and RPE were not statistically different between HRTG and RPETG. However, the distribution of exercise intensity was more tightly concentrated in HRTG. Similar improvements were noted for VO2max (4.0±2.4 mL∙kg-1∙min-1), resting HR (-5±7 bpm), body mass (-0.7±2.7 kg), BMI (-0.2±0.9 kg∙m-2), and BF% (-0.9±2.3%, all p < 0.022). HRTG displayed a greater decrease in waist circumference (-3 ± 3 cm) than RPETG (0±4 cm, p = 0.015). Conclusions: HR- and RPE-based run intensity prescription both improve fitness, and anthropomorphic and cardiometabolic risk factors. A slightly higher intensity may be responsible for larger reductions in WC in HRTG. The more precise achieved %HRR observed in HRTG may be advantageous to exercise prescription across populations.