The Study
Moderate-intensity exercise and high-intensity interval training affect insulin sensitivity similarly in obese adults.
This study showed that two kinds of workouts — one short and intense, one longer and steady — both made the body better at using sugar for one day after exercising. But if you stop working out for four days, your body forgets the benefit. It doesn't prove that either workout permanently fixes insulin problems — just that they help right after you do them.
Analysis score
Maximum 90 for a randomized controlled trial.
Where the score came from
Even if you only exercise for 25 minutes with short bursts of speed, or 45 minutes at a steady pace, your body’s ability to use sugar improves the next day — but only if you keep exercising.
Where does this study sit?
Reviews of RCTs (Meta-analyses)
Max 100Randomized Trials
Max 90Reviews of Cohort Studies
Max 85Cohort Studies
Max 72Reviews of Case-Control Studies
Max 63Case-Control Studies
Max 58Cross-Sectional & Case Series
Max 50Expert Opinion
Max 574 / 100
Quality score
Participants are randomly assigned to treatment or control groups, minimizing bias. The gold standard for testing whether an intervention causes an effect.
Key takeaways
Summary
Based on the study abstract and findings.
- 1Yes — this means you don’t need to spend hours exercising to get the same immediate sugar-control benefits as longer workouts, but you must keep doing it regularly — skipping even a few days wipes out the gain.
- 2After 12 weeks: 1) Insulin sensitivity went up 20% the day after exercise; 2) Muscle proteins for energy use increased by 70%; 3) Muscle glycogen rose 40% after 4 days off; 4) These benefits vanished after 4 days without exercise.
Score breakdown, methodology, conflicts of interest, evidence analysis & raw study data
Publication
Journal
The Journal of clinical endocrinology and metabolism
Year
2020
Authors
B. Ryan, M. Schleh, Cheehoon Ahn, Alison C Ludzki, J. Gillen, Pallavi Varshney, Douglas W. Van Pelt, Lisa M. Pitchford, T. Chenevert, R. Gioscia-Ryan, Suzette M Howton, Thomas Rode, S. Hummel, C. Burant, J. Little, J. Horowitz
Related Content
Claims (6)
In adults with obesity, doing either high-intensity interval training or moderate-intensity continuous exercise for 12 weeks does not change whole-body fat breakdown or the amount of fat in the liver and abdomen if body weight stays the same.
Twenty to thirty minutes of high-intensity training results in more metabolic improvement than several hours of moderate cardio.
In adults with obesity, 12 weeks of either high-intensity interval training or moderate-intensity continuous training increases the amount of hexokinase II protein in skeletal muscle by about 70%, which enhances the muscle's ability to take up and process glucose without relying on insulin.
In adults with obesity, 12 weeks of high-intensity interval training and moderate-intensity continuous training produce the same increase in skeletal muscle mitochondrial proteins related to energy production and fat breakdown, even though high-intensity interval training takes half the time and burns less energy.
In adults with obesity, muscle glycogen levels rise by about 40% after 12 weeks of high-intensity or moderate-intensity exercise when measured four days after the last workout, but drop back to normal when measured the next day, and this fluctuation is directly linked to short-term changes in insulin sensitivity.
In inactive adults with obesity, 12 weeks of either high-intensity or moderate-intensity exercise increases insulin sensitivity by about 20% the day after the last workout, but this increase is gone after four days without exercise.
Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.