Edwin C Chin1, Angus P Yu1, Christopher W Lai, Daniel Y Fong2, Derwin K Chan, Stephen H Wong3, Fenghua Sun4, Heidi H Ngai5, Patrick S H Yung6, Parco M Siu1. 1. Division of Kinesiology, School of Public Health, The University of Hong Kong, Pokfulam, HONG KONG. 2. School of Nursing, The University of Hong Kong, Pokfulam, HONG KONG. 3. Department of Sports Science and Physical Education, The Chinese University of Hong Kong, Pokfulam, HONG KONG. 4. Department of Health and Physical Education, The Education University of Hong Kong, Pokfulam, HONG KONG. 5. Dietitic Clinic, School of Professional and Continuing Education, The University of Hong Kong, Pokfulam, HONG KONG. 6. Department of Orthopaedics and Traumatology, The Chinese University of Hong Kong, Pokfulam, HONG KONG.
Abstract
BACKGROUND: The relationship between the frequency of high-intensity interval training (HIIT) and the resultant adaptations is largely unclear. PURPOSE: This study compared the effects of different frequencies of HIIT with those of moderate-intensity continuous training (MICT) on body composition in overweight or obese adults. METHODS:Fifty-six overweight or obese (body mass index = 26.4 ± 2.9) men between 18 and 30 yr old (age = 22.8 ± 3.1 yr) were randomly assigned to the following groups: no-intervention control (CON; n = 14), MICT performed thrice weekly (MICT×3/wk; n = 9), HIIT performed thrice weekly (HIIT×3/wk; n = 14), HIIT performed twice weekly (HIIT×2/wk; n = 10), and HIIT performed once weekly (HIIT×1/wk; n = 9). Each HIIT session consisted of 12 × 1-min bouts at 90% heart rate reserve, interspersed with 11 × 1-min bouts at 70% heart rate reserve. Aerobic capacity, body composition, resting heart rate, vascular function, insulin resistance, and biomarkers of metabolic syndrome risk factor were examined at baseline, after 4 wk, and after 8 wk of intervention. RESULTS:Aerobic capacity and percent fat-free mass significantly increased in all exercise groups compared with those in the CON group (CON vs all exercise groups, P < 0.05), whereas body fat mass and systolic blood pressure significantly decreased after 8 wk of intervention in all exercise groups compared with those in the CON group (CON vs all exercise groups, P < 0.05). Body fat mass significantly decreased after 4 wk in all HIIT groups compared with those in the CON group (CON vs all HIIT groups, P < 0.05) but not in the MICT×3/wk group. CONCLUSION: These novel results demonstrated that performing HIIT once weekly, even with a lower weekly volume of exercise, improved cardiorespiratory fitness, body composition, and blood pressure in overweight/obese adults. Low-frequency HIIT might be a feasible and effective strategy for the prescription of an initial exercise program for inactive, overweight, or obese young men.
RCT Entities:
BACKGROUND: The relationship between the frequency of high-intensity interval training (HIIT) and the resultant adaptations is largely unclear. PURPOSE: This study compared the effects of different frequencies of HIIT with those of moderate-intensity continuous training (MICT) on body composition in overweight or obese adults. METHODS: Fifty-six overweight or obese (body mass index = 26.4 ± 2.9) men between 18 and 30 yr old (age = 22.8 ± 3.1 yr) were randomly assigned to the following groups: no-intervention control (CON; n = 14), MICT performed thrice weekly (MICT×3/wk; n = 9), HIIT performed thrice weekly (HIIT×3/wk; n = 14), HIIT performed twice weekly (HIIT×2/wk; n = 10), and HIIT performed once weekly (HIIT×1/wk; n = 9). Each HIIT session consisted of 12 × 1-min bouts at 90% heart rate reserve, interspersed with 11 × 1-min bouts at 70% heart rate reserve. Aerobic capacity, body composition, resting heart rate, vascular function, insulin resistance, and biomarkers of metabolic syndrome risk factor were examined at baseline, after 4 wk, and after 8 wk of intervention. RESULTS: Aerobic capacity and percent fat-free mass significantly increased in all exercise groups compared with those in the CON group (CON vs all exercise groups, P < 0.05), whereas body fat mass and systolic blood pressure significantly decreased after 8 wk of intervention in all exercise groups compared with those in the CON group (CON vs all exercise groups, P < 0.05). Body fat mass significantly decreased after 4 wk in all HIIT groups compared with those in the CON group (CON vs all HIIT groups, P < 0.05) but not in the MICT×3/wk group. CONCLUSION: These novel results demonstrated that performing HIIT once weekly, even with a lower weekly volume of exercise, improved cardiorespiratory fitness, body composition, and blood pressure in overweight/obese adults. Low-frequency HIIT might be a feasible and effective strategy for the prescription of an initial exercise program for inactive, overweight, or obese young men.
Authors: Angus P Yu; Edwin C Chin; Danny J Yu; Daniel Y Fong; Calvin P Cheng; Xiaoqing Hu; Gao X Wei; Parco M Siu Journal: Sci Rep Date: 2022-05-25 Impact factor: 4.996
Authors: Edwin C Chin; Chit K Leung; Danny J Yu; Angus P Yu; Joshua K Bernal; Christopher W Lai; Derwin K C Chan; Heidi H Ngai; Patrick S H Yung; Chi H Lee; Daniel Y Fong; Shelley E Keating; Jeff S Coombes; Parco M Siu Journal: J Exerc Sci Fit Date: 2022-03-14 Impact factor: 3.103