# High-Intensity Interval Circuit Training Versus Moderate-Intensity Continuous Training on Functional Ability and Body Mass Index in Middle-Aged and Older Women: A Randomized Controlled Trial PMID: 31671584 Journal: International Journal of Environmental Research and Public Health Published: 2019-10-30 Authors: Ballesta-García I, Martínez-González-Moro I, Rubio-Arias JÁ, Carrasco-Poyatos M ## Question To determine whether high-intensity interval circuit training or moderate-intensity continuous training induces greater adaptations in functional ability and BMI in middle-aged and older women. ## Summary This randomized controlled trial compared high-intensity interval circuit training, moderate-intensity continuous circuit training, and a non-exercise control group in independent middle-aged and older women. Both exercise groups trained twice weekly for 18 weeks. HIICT improved upper-limb strength more than MICT and control, and HIICT improved BMI compared with control. Both HIICT and MICT improved lower-limb strength, gait/dynamic balance, and 6-minute walk performance compared with control. Five adverse events occurred in the MICT and control groups and did not occur during exercise classes. ## Population - Independent middle-aged and older women from elderly day care centres in Murcia, Spain. - Sample size: 54 - Age: 67.8 +/- 6.2 years overall; inclusion 55-85 years. - Sex: Women only. - Fitness level: Able to perform activities of daily living; not in a similar exercise program in the previous three months. - Health status: Independent older women; controlled hypertension allowed; uncontrolled hypertension and interfering cardiac, respiratory, or joint diseases excluded. ## Methodology - 18-week quasi-experimental randomized controlled trial with HIICT, MICT, and non-exercise control groups - 18 weeks - Elderly day care centres in Murcia, Spain - Randomized and controlled study design. ## Protocol - High-intensity interval circuit training. - Modality: Functional circuit training using lower- and upper-limb movements with bodyweight and external load progressions. - Work intervals: 1-1.5 min. - Recovery: 2-2.5 min. - Sets or repetitions: 6-12 intervals depending on mesocycle. - Intensity: RPE 14-18 overall; work intervals progressed from 14-15 to 16-18 on Borg 6-20 scale. - Session duration: 1 hour per session; HIICT exercise volume 18-40 min depending on mesocycle. - Frequency: 2 sessions per week. - Program length: 18 weeks. - Progression: 2-week familiarization and four 4-week mesocycles with progressive volume, interval count, movement complexity, external load, and intensity. - Moderate-intensity continuous circuit training and no-exercise control. - Modality: MICT used similar lower- and upper-limb circuit movements at moderate speeds; control maintained normal activity habits. - Work intervals: Continuous MICT exercise rather than interval work. - Recovery: No interval recovery structure for MICT. - Intensity: MICT targeted RPE 9-14, beginning at 6-7 and ending at 12-14; RPE asked every 5 min. - Session duration: 1 hour per session for MICT. - Frequency: 2 sessions per week for MICT. - Program length: 18 weeks. - Progression: Same two-week familiarization and four 4-week mesocycle structure, with MICT volume progressing from 18-32 min to 40-50 min and intensity progressing to RPE 12-14. ## Outcomes ### Arm curl test Status: improved A significant training x group interaction was found; HIICT was statistically better than MICT and control. Increment means were CG 1.8 reps, MICT -0.5 reps, and HIICT 2.8 reps. Training x group F=8.1, p=8.99e-4, eta2=0.192; HIICT better than MICT by 6.6 reps and CG by 9.3 reps in reported pairwise contrasts. ### 30-second sit-to-stand Status: improved Both HIICT and MICT were statistically better than control for lower-limb strength. Increment means were CG -1.9 reps, MICT 3.8 reps, and HIICT 5.6 reps. Training x group F=17.42, p=1.81e-6, eta2=0.381; HIICT better than CG by 5.6 reps and MICT better than CG by 3.2 reps. ### Timed up and go Status: improved Both HIICT and MICT were statistically better than control for gait/dynamic balance. Increment means were CG 0.36 s, MICT -0.87 s, and HIICT -0.78 s. Training x group F=11.41, p=8.30e-5, eta2=0.281; HIICT better than CG by -0.78 s and MICT better than CG by -0.23 s. ### 6-minute walk test Status: improved Both HIICT and MICT were statistically better than control for 6MWT distance. Increment means were CG -16 m, MICT 43 m, and HIICT 36 m. Training x group F=9.34, p=3.57e-4, eta2=0.256; HIICT better than CG by 43 m and MICT better than CG by 55 m in reported pairwise contrasts. ### BMI Status: improved HIICT was statistically better than control for BMI. Increment means were CG +0.3 kg/m2, MICT -0.1 kg/m2, and HIICT -0.3 kg/m2. Training x group F=6.99, p=0.002, eta2=0.215; HIICT better than CG by -1.4 kg/m2. ### Adverse events Status: mixed Five adverse events were registered in MICT and control groups, causing loss to follow-up; none occurred during exercise classes. ## Practical Insights - For independent older women, HIICT can be structured as progressive functional circuits with RPE-guided work intervals rather than all-out efforts. - Moderate continuous circuit training improved several functional outcomes similarly to HIICT, so HIICT superiority should not be generalized across all functional domains. - A two-week familiarization period and RPE education may be useful before higher-intensity circuits in older adults. - Bodyweight and functional-movement circuits are more directly adaptable to app workouts than bike- or lab-based HIIT, but this study's sessions were long and supervised. ## Limitations - Participants and instructors could not be blinded - Final analyzed sample was 41 of 54 randomized participants - Population limited to independent middle-aged and older women - No long-term follow-up - Warm-up and cool-down durations were not specified - Achieved session RPE distributions were not reported ## Safety And Adherence - Four women in MICT and one in control were lost to follow-up due to eye surgery, foot surgery, clavicle fracture, and two hip fractures after a fall. - The article states these adverse events did not occur during exercise classes. - No HIICT exercise-class adverse event was reported in the extracted text. ## Original Sources - [PubMed](https://pubmed.ncbi.nlm.nih.gov/31671584/) (pubmed) - [DOI](https://doi.org/10.3390/ijerph16214205) (doi) - [PMC full text](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6862704/) (full text) ## Agent Guidance Preserve the paper-level scope of this note. Do not generalize beyond the population, protocol, measured outcomes, and limitations above.