title: Running sprint interval training induces fat loss in women.
abstract: Data on whether sprint interval training (SIT) (repeated supermaximal intensity, short-duration exercise) affects body composition are limited, and the data that are available suggest that men respond more favourably than do women. Moreover, most SIT data involve cycling exercise, and running may differ because of the larger muscle mass involved. Further, running is a more universal exercise type. This study assessed whether running SIT can alter body composition (air displacement plethysmography), waist circumference, maximal oxygen consumption, peak running speed, and (or) the blood lipid profile. Fifteen recreationally active women (age, 22.9 ± 3.6 years; height, 163.9 ± 5.1 cm; mass, 60.8 ± 5.2 kg) completed 6 weeks of running SIT (4 to 6, 30-s "all-out" sprints on a self-propelled treadmill separated by 4 min of rest performed 3 times per week). Training decreased body fat mass by 8.0% (15.1 ± 3.6 to 13.9 ± 3.4 kg, P = 0.002) and waist circumference by 3.5% (80.1 ± 4.2 to 77.3 ± 4.4 cm, P = 0.048), whereas it increased fat-free mass by 1.3% (45.7 ± 3.5 to 46.3 ± 2.9 kg, P = 0.05), maximal oxygen consumption by 8.7% (46 ± 5 to 50 ± 6 mL/(kg·min), P = 0.004), and peak running speed by 4.8% (16.6 ± 1.7 to 17.4 ± 1.4 km/h, P = 0.026). There were no differences in food intake assessed by 3-day food records (P > 0.329) or in blood lipids (P > 0.595), except for a slight decrease in high-density lipoprotein concentration (1.34 ± 0.28 to 1.24 ± 0.24 mmol/L, P = 0.034). Running SIT is a time-efficient strategy for decreasing body fat while increasing aerobic capacity, peak running speed, and fat-free mass in healthy young women.
authors.affiliation: a Department of Kinesiology and Physical Education, Faculty of Arts and Science, University of Lethbridge, Lethbridge, AB T1K 3M4, Canada.
authors.forename: Tom J
authors.initials: TJ
authors.lastname: Hazell
authors.forename: Craig D
authors.initials: CD
authors.lastname: Hamilton
authors.forename: T Dylan
authors.initials: TD
authors.lastname: Olver
authors.forename: Peter W R
authors.initials: PW
authors.lastname: Lemon
mesh_terms: D000273:Adipose Tissue; D001823:Body Composition; D005260:Female; D006801:Humans; D012420:Running / Q000502:physiology*; D013997:Time Factors; D015431:Weight Loss; D055815:Young Adult
keywords: body composition; body fat; composition corporelle; entraînement par intervalle de haute intensité; female; femme; gras corporel; high-intensity interval training; lean mass; masse maigre