Research papers

Relevant research about the CAROL workouts in theory and in practice are available to download from the links below

American Council of Exercise (ACE): Acute and Chronic Responses to Reduced-Exertion High Intensity Training.

Over 8 weeks 32 participants were split into two groups to test the effectiveness of CAROL’s workouts and compare it with existing government guidelines on exercise. Read what ACE-sponsored research found to be the most time-efficient way to achieve meaningful health and fitness benefits.

American Council of Exercise

BBC 5-Week Experiment Results.

6 volunteers in a real-life work environment experience CAROL and track their progress while using her over a 5 week period. Read the result from BBC live television case study. 

Neils B.J. Vollaard

The Effects of High-Intensity Intermittent Exercise Training on Fat Loss of Young Women

This study was created to explain the effects of a 15-week high-intensity intermittent exercise (HIIE) program on subcutaneous and trunk fat and insulin resistance of young women. 

EG Trapp, DJ Chisholm, J Freund and SH Boutcher


This study’s goal was to determine the effectiveness of an 8 week  Reduced-Exertion High-Intensity Interval training (REHIT) at improving Cardiorespiratory Fitness (CRF) and positively modifying health in the workplace environment. 

Tom F. Cuddy, Joyce S. Ramos and Lance C. Dalleck

Beneficial Effects of Reduced-Excursion High Intensity Interval Training (REHIT)

High-intensity interval training (HIT) has been proposed as a time-efficient alternative to traditional cardiorespiratory exercise training, but is very fatiguing. This study investigates the effects of a Reduced-Excretion HIT (REHIT) exercise intervention on insulin sensitivity and aerobic capacity. 

Richard S. Metcalfe • John A. Babraj • Samantha G. Fawkner • Niels B. J. Vollaard