A new study, conducted under the leadership of IDEA author and presenter Len Kravitz, PhD, compared cardiovascular and metabolic responses to two exercise protocols: (1) six bouts of high-intensity interval training (HIIT) followed by three rounds of circuit weight training (CWT) and (2) CWT rounds interspersed with HIIT bouts. Fourteen trained young men (ages 25.7 ± 4.4) participated in the study, completing each of the two programs 3 days apart.

Data analysis showed that participants enjoyed both protocols but found it more interesting to complete HIIT program and then do CWT. This protocol required higher energy expenditure, elicited greater excess post-exercise oxygen consumption and generated more blood lactate, even though participants rated perceived exertion equally for both workouts. Study authors suggest that integrating HIIT with CWT (the second protocol) may be preferred for beginners and that both programs could be beneficial for improving muscular fitness and aerobic endurance.

The study appeared in the Journal of Exercise Science & Fitness (2020; 18 [1], 14–20)