Background: High-intensity functional training is a popular form of exercise, but little is known about how it compares to more traditional exercise patterns.
Methods: Thirty healthy, physically active adults (15 males, 15 females) performed a high-intensity functional training workout (HIFT) and a traditional workout (TRAD). Cardiorespiratory responses were measured during and for 15 min after each workout.
Results: Peak heart rate (males: 187±7 vs. 171±10 bpm, P<0.001; females: 191±9 vs. 175±6 bpm, P<0.001), peak VO<inf>2</inf> (males: 3.80±0.58 vs. 3.26±0.60 L/min, P<0.001; females: 2.65±0.26 vs. 2.36±0.21, P<0.001), and average 15 min recovery VO<inf>2</inf> (males: 1.15±0.20 vs. 0.99±0.17 L/min, P<0.001; females: 0.77±0.10 vs. 0.71±0.07 L/min, P=0.019) were significantly higher in HIFT vs. TRAD. Aerobic energy expenditure was significantly higher in HIFT compared to TRAD in males (9.01±1.43 vs. 8.53±1.38 kcal/min, P=0.002) but was not significantly different between the two workouts in females (6.04±0.53 vs. 5.97±0.50 kcal/min, P=0.395). Postexercise systolic blood pressure (SBP) was significantly higher than pre-exercise SBP following both HIFT (males: 124±13 mmHg pre to 154±28 mmHg post, P<0.001; females: 110±7 mmHg pre to 140±15 mmHg post, P<0.001) and TRAD (males: 124±13 mmHg pre to 142±16 mmHg post, P=0.002; females: 112±8 mmHg pre to 123±10 mmHg post, P=0.002), however, HIFT led to a greater increase compared to TRAD in females (P=0.001). Postexercise diastolic blood pressure (DBP) was significantly lower than pre-exercise DBP following both HIFT (males: 77±9 mmHg pre to 64±6 mmHg post, P<0.001; females: 71±8 mmHg pre to 64±7 mmHg post, P=0.011) and TRAD (males: 82±7 mmHg pre to 72±7 mmHg post, P<0.001; females: 73±8 mmHg pre to 65±8 mmHg post, P<0.001). Mean arterial blood pressure was unchanged following both workouts.
Conclusions: High-intensity functional training may be an effective form of exercise for caloric expenditure and may elicit greater cardiorespiratory stress than traditional exercise.