Dissimilar Physiological and Perceptual Responses Between Sprint Interval Training and High-Intensity Interval...

Area of Science:

• Exercise Physiology
• Sports Science
• Cardiovascular Health

Background:

• High-intensity interval training (HIIT) and sprint interval training (SIT) are known for similar cardiovascular and metabolic adaptations compared to traditional endurance training.
• However, acute physiological responses during HIIT versus SIT have not been extensively studied.

Purpose of the Study:

• To compare acute physiological changes, including heart rate (HR), blood lactate concentration (BLa), oxygen uptake (VO2), affect, and rating of perceived exertion (RPE), between HIIT and SIT.

Main Methods:

• Eight male and four female active adults underwent a VO2max test to establish workloads for randomized HIIT and SIT sessions on a cycle ergometer.
• Sprint interval training (SIT) involved 8 x 30-second all-out cycling bouts at 130% of maximal Watts (Wmax).
• High-intensity interval training (HIIT) consisted of 8 x 60-second bouts at 85% Wmax, with continuous monitoring of HR, VO2, BLa, affect, and RPE.

Main Results:

• Significant differences were observed between HIIT and SIT for VO2 (p < 0.001), HR (p < 0.001), RPE (p = 0.03), and BLa (p = 0.049).
• Energy expenditure was significantly higher during HIIT (209.3 ± 40.3 kcal) compared to SIT (193.5 ± 39.6 kcal, p = 0.02).
• Affective response did not significantly differ between the two training regimens (p = 0.12).

Conclusions:

• HIIT resulted in higher energy expenditure and oxygen uptake, with lower perceived exertion compared to SIT.
• The distinct metabolic perturbations between HIIT and SIT suggest potential for unique long-term adaptations.
• HIIT is recommended for individuals aiming to maximize calorie burn, enhance oxygen uptake, and experience lower perceived exertion during exercise.