PMID 32245173

Research
All papers

High-intensity Interval Training Promotes the Shift to a Health-Supporting Dietary Pattern in Young Adults

Donati Zeppa S, Sisti D, Amatori S, Gervasi M, Agostini D, Piccoli G, Bertuccioli A, Rocchi MBL, Stocchi V, Sestili P

Question

Does a 9-week progressive HIIT program change spontaneous dietary intake and body composition in healthy young adults?

Summary

In healthy young adults, 9 weeks of supervised cycling HIIT did not reduce body weight but was accompanied by higher energy intake, higher fat-free mass, and a shift toward a diet pattern with more fish, nuts, seeds, oils, fruit, vegetables, and cereals.

Methodology

  • Healthy, normal-weight collegiate young adults who were not regularly active
  • 32 participants.
  • Indoor cycling.
  • Work intervals: Intervals longer than 4 min in HR zone 2 and 2-4 min in HR zone 3.
  • Recovery: Active recovery in HR zone 1.
  • Intensity: Polarized HR-zone model: about 70% zone 1, 10% zone 2, 20% zone 3.
  • Warm-up, high-intensity interval section, and cool-down; exact session duration varied by mesocycle.
  • Progressed up to 5 sessions/week in the third mesocycle.
  • 9 weeks.
  • Within-subject supervised training study
  • Dietary intake, Body composition, and Training completion were tracked.

Outcomes

Diet quality

Participants shifted toward a pattern with more health-supporting food choices.

Time effect across dietary and body-composition variables: Wilks lambda 0.153, F(57,215) = 3.314, p < 0.001; factor analysis described more fish, oils, nuts, seeds, fruit, vegetables, and cereals

Improved

Energy intake

Total energy intake increased during training.

+9.4% at T1, p = 0.001; +17.8% at T3, p < 0.01

Safety concern

Fat-free mass

Fat-free mass increased while body weight did not significantly change.

Fat-free mass +3.8% at T3, p < 0.001; body weight no significant change

Improved

Macronutrients

Absolute protein, fat, and carbohydrate intake increased, but macronutrient proportions stayed similar.

Protein +18.5% at T3, p < 0.01; fat +19.4%, p = 0.015; carbohydrates +17.1%, p = 0.036

Mixed

Insights

  • Progressive HIIT may influence eating behavior even when participants are not instructed to change diet.
  • Body-weight stability can mask increased fat-free mass during a young-adult HIIT program.
  • Dietary intake should be monitored in HIIT studies because spontaneous compensation can occur.

Limitations

  • No non-exercise control group
  • Small healthy young-adult sample
  • Diet was self-reported by daily contact and photos
  • Not designed to isolate which HIIT dose element drove dietary changes

Safety

  • No exercise-related adverse events were reported in the article text; all participants completed the overall program.