# Effect of High-Intensity Interval Training on Quality of Life, Sleep Quality, Exercise Motivation and Enjoyment in Sedentary People with Type 1 Diabetes Mellitus

PMID: 34886337
Journal: International Journal of Environmental Research and Public Health
Published: 2021-11-30
Authors: Alarcón-Gómez J, Chulvi-Medrano I, Martin-Rivera F, Calatayud J

## Question

Does supervised HIIT improve quality of life, sleep quality, exercise motivation, and enjoyment in sedentary adults with type 1 diabetes?

## Summary

In sedentary adults with type 1 diabetes, 6 weeks of supervised cycling HIIT improved several self-reported quality-of-life domains, sleep quality, exercise enjoyment, and more self-determined motivation compared with a lifestyle-maintenance control group. Mild hypoglycemia occurred after 1.5% of training sessions and resolved with carbohydrate intake and rest. The study was small and short.

## Population

- Nineteen sedentary adults with type 1 diabetes: HIIT n=11 and control n=8. Participants were 18-45 years old, had type 1 diabetes for more than 4 years, HbA1c below 10%, no structured exercise in the prior 6 months, and no known comorbidities.
- Sample size: 19
- Age: HIIT 38 +/- 5.5; control 35 +/- 8.2 years
- Sex: 10 male, 9 female overall
- Fitness level: Sedentary; no structured exercise in previous 6 months
- Health status: Type 1 diabetes duration >4 years, HbA1c <10%, no known comorbidities

## Methodology

- Randomized controlled parallel trial
- 6 weeks
- Supervised cycle ergometer sessions
- Randomized and controlled study design.

## Protocol

- Supervised cycle ergometer HIIT in T1DM; details: Supervised cycling HIIT 3 times/week for 6 weeks. Each session included 5 min at 50 W, then 30 sec at 85% peak power output with 1 min active recovery at 40% peak power output, progressing from 12 to 16 to 20 repetitions, and 5 min cool-down at 50 W. No insulin dose adjustments were made; glucose safety procedures determined whether sessions proceeded.
- Modality: Cycle ergometer HIIT.
- Work intervals: 30 sec.
- Recovery: 1 min.
- Sets or repetitions: 12 reps weeks 1-2, 16 reps weeks 3-4, 20 reps weeks 5-6.
- Intensity: High-intensity bouts at 85% peak power output; active recovery at 40% peak power output.
- Session duration: About 28-40 min depending on progression.
- Frequency: 3.
- Program length: 6 weeks.
- Progression: Number of intervals increased every 2 weeks.
- Usual lifestyle control; details: Control participants maintained usual lifestyle and diet.
- Modality: Cycle ergometer HIIT.
- Work intervals: 30 sec.
- Recovery: 1 min.
- Sets or repetitions: 12 reps weeks 1-2, 16 reps weeks 3-4, 20 reps weeks 5-6.
- Intensity: High-intensity bouts at 85% peak power output; active recovery at 40% peak power output.
- Session duration: About 28-40 min depending on progression.
- Frequency: 3.
- Program length: 6 weeks.
- Progression: Number of intervals increased every 2 weeks.

## Outcomes

### SF-36 quality-of-life domains
Status: no clear change
HIIT improved several SF-36 domains including physical functioning, physical role limitations, pain, general health, energy/fatigue, and social functioning; control did not change.

### Sleep quality
Status: improved
Sleep quality improved in the HIIT group, with PSQI indicating a move toward better sleep quality.

### Exercise motivation
Status: no clear change
HIIT improved intrinsic and identified motivation and reduced external regulation and amotivation; control did not show comparable changes.

### Exercise enjoyment increased after HIIT.
Status: improved
Exercise enjoyment increased after HIIT.

### Mild hypoglycemia events
Status: mixed
Three mild hypoglycemia cases occurred in 198 training sessions (1.5%), immediately after exercise, and resolved with rest and carbohydrate ingestion.

## Practical Insights

- Supervised HIIT can be enjoyable and motivating in a clinical group when safety rules are explicit.
- Consumer products should not generalize this to unsupervised T1DM HIIT without glucose monitoring and medical guidance.
- Short progressive interval prescriptions may support perceived quality-of-life and motivation outcomes.

## Limitations

- Small sample and short intervention.
- No type 1 diabetes-specific quality-of-life questionnaire.
- No objective sleep measurement.
- Diet was not measured.
- No medical specialists were part of the research team, although university medical services were aware.

## Safety And Adherence

- Three mild hypoglycemia cases (mean 67.9 +/- 2.6 mg/dL) occurred immediately after exercise.
- No adverse cardiac, respiratory, or musculoskeletal injuries were reported.
- No hyperglycemia, nocturnal hypoglycemia, or ketoacidosis was reported.

## Original Sources

- [PubMed](https://pubmed.ncbi.nlm.nih.gov/34886337/) (pubmed)
- [DOI](https://doi.org/10.3390/ijerph182312612) (doi)
- [PMC full text](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8656786/) (full text)

## Agent Guidance

Preserve the paper-level scope of this note. Do not generalize beyond the population, protocol, measured outcomes, and limitations above.