High-intensity interval training improves insulin sensitivity in individuals with prediabetes.
Study Goal
The researchers aimed to examine the separate and combined effects of low-volume HIIT and walking on insulin sensitivity and skeletal metabolic capacity in individuals with prediabetes.
Results Summary
HIIT alone and HIIT combined with walking significantly improved peripheral insulin sensitivity, while walking alone did not. Whole-body insulin sensitivity improved significantly with HIIT + walking and walking alone, but not with HIIT alone. HIIT + walking also enhanced mitochondrial capacity and glucose uptake proteins in skeletal muscle.
Population
Sedentary individuals with prediabetes (n=70, 36 women, mean age 60.8 ± 11.3 years, BMI 31.6 ± 4.4 kg/m²).
Effective Dosage
HIIT (3 × 20-second cycle sprints, 3 times weekly) + walking (>10,000 steps/day) or walking alone.
Duration
12 weeks
Interactions
None mentioned
| Intervention | Direction | Endpoint | Population | Dosage | Impact | Claim # |
|---|---|---|---|---|---|---|
low-volume high-intensity interval training (HIIT) | increase | peripheral insulin sensitivity (measured by the Cederholm index) | individuals with prediabetes | 18.5% | significantly improved | #1 |
HIIT + walking | increase | peripheral insulin sensitivity (measured by the Cederholm index) | individuals with prediabetes | 15.7% | significantly improved | #2 |
walking alone | no change | peripheral insulin sensitivity (measured by the Cederholm index) | individuals with prediabetes | 9.4% | not significantly improved | #3 |
HIIT + walking | increase | whole-body insulin sensitivity (measured by the Matsuda index) | individuals with prediabetes | 28.0% | significantly increased | #4 |
walking alone | increase | whole-body insulin sensitivity (measured by the Matsuda index) | individuals with prediabetes | 42.3% | significantly increased | #5 |
HIIT alone | no change | whole-body insulin sensitivity (measured by the Matsuda index) | individuals with prediabetes | 17.0% | not significantly increased | #6 |
HIIT + walking | increase | protein expression of proteins involved in mitochondrial capacity in skeletal muscle and glucose uptake | individuals with prediabetes | - | most improved | #7 |
walking alone | no change | protein expression of proteins involved in mitochondrial capacity in skeletal muscle and glucose uptake | individuals with prediabetes | - | no significant effects | #8 |
low-volume HIIT training | increase | glucose control | individuals with prediabetes | - | can improve | #9 |
low-volume HIIT training | increase | skeletal muscle important for metabolic health | individuals with prediabetes | - | induces adaptations | #10 |
OBJECTIVE: To examine the separate and combined effects of low-volume high-intensity interval training (HIIT) and walking compared with no training on insulin sensitivity and skeletal metabolic capacity in individuals with prediabetes. DESIGN: Individuals were randomized to: (1) control (no exercise), (2) HIIT (3 × 20 s's cycle sprint 3 times weekly), (3) HIIT + walking (walking >10 000 steps/day), or (4) walking for 12 weeks. METHODS: Insulin sensitivity was assessed by an oral glucose tolerance test at baseline and end-of-trial. Additionally, proteins important for mitochondria capacity and insulin sensitivity were measured in the vastus lateralis muscle. RESULTS: Seventy sedentary individuals with prediabetes (women n = 36; age: 60.8 ± 11.3 years (mean ± SD); body mass index: 31.6 ± 4.4 kg/m2; fasting plasma glucose: 6.6 ± 0.8 mmol/L; glycated hemoglobin A1c 5.7 ± 0.4% (39.0 ± 4.3 mmol/mol) were included. Compared with control, peripheral insulin sensitivity (measured by the Cederholm index) was significantly improved with HIIT (estimated treatment difference [ETD]: 18.5% [95% confidence interval (CI): 7.4; 28.3%] and HIIT + walking [ETD: 15.7% (95% CI: 4.4; 25.6%)]), but not with walking alone (ETD: 9.4% [95% CI: -2.5; 19.9%]). Whole-body insulin sensitivity (measured by the Matsuda index) was significantly increased with HIIT + walking (ETD: 28.0% [95% CI: 10.3; 42.3%]) and walking alone (ETD: 42.3% [95% CI: 28.3; 53.5%]), but not with HIIT alone (ETD: 17.0% [95% CI: -4.0; 33.7%]). Protein expression of proteins involved in mitochondrial capacity in skeletal muscle and glucose uptake were most improved with HIIT + walking, and no significant effects were observed with walking alone. CONCLUSIONS: Twelve weeks of low-volume HIIT training can improve glucose control and induces adaptations in skeletal muscle important for metabolic health in individuals with prediabetes.