Study analysis · European Journal of Applied Physiology · 2018
Two 20-second bike sprints in a 10-minute workout cut high-blood-sugar time by an absolute 112 minutes over 24 hours in men with type 2 diabetes.
In 11 men with well-controlled type 2 diabetes, a single 10-minute REHIT session lowered 24-hour average blood sugar by an absolute 0.58 mmol/L and reduced time above 9 mmol/L by an absolute 112 minutes compared with no exercise.
Overview
What the study found
The study in plain English — the bottom line, every takeaway we extracted, and what to do with them.
In simple terms
This study tested a very short burst of exercise in 11 men with diabetes. Because the men were randomly assigned to different exercise orders, we can be fairly confident that the exercise changed their blood sugar for that day, but it doesn't tell us about long-term health or whether it works for everyone.
What’s the bottom line?
In 11 men with well-controlled type 2 diabetes, one 10-minute REHIT session (two 20-second all-out bike sprints) lowered 24-hour average blood sugar and reduced high-blood-sugar time compared with no exercise.
How strong is this study?
The study was well-controlled because everyone ate the same meals and wore a glucose monitor, but it only included 11 men and the participants knew which exercise they were doing. That means the results are promising but not final; larger studies are needed to confirm them.
0 / 100
- COI disclosureconflicts of interest not disclosed
- Data availabilitydata not shared
- Code availabilitycode not shared
58 / 100
- Randomization+20/20
- Blindingblinding unclear
- Control group+15/15
- Sample size (n=11)+1.1/20
- Follow-up+10/10
100 / 100
100 / 100
- P-values+15/15
- Effect size+20/20
- Confidence intervals+15/15
- Pre-registration+15/15
Each component is scored out of 100 and then capped by the study design — a case series cannot reach the ceiling a randomised trial can, however well it is reported.
Where it sits
RCT reviewsReviews of RCTs (Meta-analyses)
Max 100Randomized TrialsRandomized Trials
Max 90Reviews of Cohort StudiesReviews of Cohort Studies
Max 85Cohort StudiesCohort Studies
Max 72Reviews of Case-Control StudiesReviews of Case-Control Studies
Max 63Case-Control StudiesCase-Control Studies
Max 58Cross-Sectional & Case SeriesCross-Sectional & Case Series
Max 50Expert OpinionExpert Opinion
Max 565 / 100
Probability of being correct
Participants are randomly assigned to treatment or control groups, minimizing bias. The gold standard for testing whether an intervention causes an effect.
This design can establish causation. The randomized crossover design with a no-exercise control supports causal inference for acute effects of REHIT on 24-h glycaemia in this sample. However, the very small sample (n=11), lack of blinding (though exercise interventions are difficult to blind), multiple comparisons, and acute single-bout design limit the strength and generalizability of causal claims. Causation can be inferred for short-term glycaemic changes, but not for long-term outcomes such as HbA1c, complications, or cardiovascular risk.
No Conflicts
No conflicts of interest identified
No conflicts of interest or funding sources were disclosed in the provided text.
The provided text lacks a conflict of interest or funding statement. The study was registered (NCT03082859) and approved by an ethics committee. No author affiliations are listed, so potential industry ties cannot be assessed. Commercial devices (Medtronic, Roche, Lode, Cosmed, Actiheart) are mentioned, but no funding or conflicts are declared.
Key takeaways
- 01
In 11 men with type 2 diabetes, one 10-minute REHIT session lowered 24-hour average blood sugar by an absolute 0.58 mmol/L and cut time spent above 9 mmol/L by an absolute 112 minutes (about 1 hour 52 minutes) over 24 hours compared with no exercise.
- 02
The blood sugar response to dinner was 11% lower relative, but the absolute reduction was not reported.
- 03
A 30-minute moderate workout (MICT) lowered average blood sugar by 0.37 mmol/L but this was not statistically significant (p=0.08).
- 04
HIIT did not significantly lower average blood sugar but reduced time above 9 mmol/L by 125 minutes.
- 05
For a man with well-controlled type 2 diabetes, a single 10-minute REHIT session may meaningfully lower average blood sugar and reduce high-blood-sugar time by nearly 2 hours over the next day.
- 06
However, this was a small, short-term study (11 men, 24 hours) and does not prove long-term benefits like fewer complications.
- 07
The absolute risk reduction for diabetes complications was not reported.
Surprising findings
- REHIT significantly lowered 24-hour mean glucose while HIIT did not, despite HIIT requiring far more time and effort.Conventional wisdom says more high-intensity exercise should produce larger glucose benefits.
- All three exercise conditions reduced time in hyperglycaemia, even when mean glucose was not significantly changed, as with HIIT.Suggests exercise can reduce high-glucose exposure without moving average glucose much.
- Exercise effects were only seen for dinner, not breakfast or lunch.Most people expect exercise to blunt the next meal's glucose, but the first two meals were unaffected.
- No improvement in glycaemic variability indices.Many assume exercise smooths out glucose swings, but this study found no change.
Practical takeaways
If you have well-controlled type 2 diabetes and limited time, discuss with your doctor whether a 10-minute REHIT session (two 20-second all-out bike sprints within 10 minutes) could fit your routine.
Study only included 11 men, a single session, and 24-hour outcomes; not a substitute for medical advice or guidelines.
low confidenceTry scheduling exercise after breakfast; in this study, morning exercise was associated with lower dinner glucose response, not breakfast or lunch.
Absolute dinner AUC reduction was not reported; breakfast and lunch were unchanged; findings are preliminary.
low confidenceUse CGM if available to see your individual 24-hour glucose response to different exercise types.
CGM variability can be high; this study standardized diet but was otherwise free-living.
medium confidenceDon't abandon moderate exercise: MICT reduced 24-hour iAUC and dinner AUC, and guidelines still recommend regular moderate activity.
MICT's 24-hour mean glucose reduction was nonsignificant (p=0.08).
medium confidenceTrack time in hyperglycaemia, not just average glucose, if you use CGM; REHIT cut time ≥9 mmol/L by about 112 minutes.
Threshold of 9 mmol/L; individual targets vary.
low confidenceWhy this study matters
10-minute workout, 40 seconds of sprints
A single REHIT session — 10 minutes of cycling with two 20-second all-out sprints — lowered 24-hour mean glucose by an absolute 0.58 mmol/L (95% CI 0.17–0.99; p=0.008; d=0.55) vs no exercise in 11 men with well-controlled type 2 diabetes. MICT (30 min) showed a nonsignificant absolute 0.37 mmol/L reduction (p=0.08); HIIT (10×1 min) did not significantly lower mean glucose (absolute 0.37 mmol/L, p=0.31).
Time is a common barrier. A 10-minute session with only 40 seconds of hard effort may fit into busy lives.
Nearly 2 fewer hours in high blood sugar
REHIT reduced time in hyperglycaemia (glucose ≥9 mmol/L) by an absolute 112 minutes over 24 hours vs no exercise (p=0.002, d=0.50). HIIT reduced it by an absolute 125 minutes (p=0.04) and MICT by an absolute 115 minutes, but MICT was not statistically significant (p=0.08).
Time in high blood sugar is linked to complications; cutting about 2 hours per day is tangible.
Dinner, not breakfast or lunch
The 24-hour benefit seemed driven by a lower glucose response to dinner: REHIT and MICT each reduced dinner AUC by 11% relative (p<0.05; absolute reduction not reported). HIIT only reduced dinner AUC by 4% relative (p=0.22). Breakfast and lunch responses were not significantly changed.
Meal timing matters. Morning exercise may shape evening blood sugar more than earlier meals.
HIIT paradox: longer and harder didn't win
HIIT involved 10×1-minute efforts at ~90% HRmax and ~25 min total time, yet it did not significantly lower 24-hour mean glucose or dinner AUC. REHIT, with just two 20-second sprints, did. HIIT did reduce hyperglycaemia time.
Challenges the assumption that more high-intensity work is always better for glucose.
Glycaemic variability unchanged
None of the exercise conditions significantly altered 24-hour glycaemic variability indices: standard deviation, glycaemic range, MAGE, or CONGA. The benefits were in mean glucose and hyperglycaemia time, not in smoothing swings.
People might assume exercise stabilizes blood sugar overall; this shows a more specific effect.
Tiny but promising study
Only 11 men with well-controlled type 2 diabetes (HbA1c 7.0±0.8%) completed this acute crossover trial. Effects were measured for 24 hours only; long-term outcomes and absolute dinner AUC reduction were not reported.
Important caveat: promising signal, not proof.
Want the whole report?
Detailed mode opens the full scientific breakdown — every score component, the methodology, conflicts of interest, the evidence analysis behind each claim, and the raw study data.
Overview
What the study found
The study in plain English — the bottom line, every takeaway we extracted, and what to do with them.
Not medical advice. For informational purposes only. Always consult a healthcare professional. Terms
In 11 men with well-controlled type 2 diabetes, one 10-minute REHIT session (two 20-second all-out bike sprints) lowered 24-hour average blood sugar and reduced high-blood-sugar time compared with no exercise.
Research results
In 11 men with type 2 diabetes, one 10-minute REHIT session lowered 24-hour average blood sugar by an absolute 0.58 mmol/L and cut time spent above 9 mmol/L by an absolute 112 minutes (about 1 hour 52 minutes) over 24 hours compared with no exercise. The blood sugar response to dinner was 11% lower relative, but the absolute reduction was not reported. A 30-minute moderate workout (MICT) lowered average blood sugar by 0.37 mmol/L but this was not statistically significant (p=0.08). HIIT did not significantly lower average blood sugar but reduced time above 9 mmol/L by 125 minutes.
What this means - more context
For a man with well-controlled type 2 diabetes, a single 10-minute REHIT session may meaningfully lower average blood sugar and reduce high-blood-sugar time by nearly 2 hours over the next day. However, this was a small, short-term study (11 men, 24 hours) and does not prove long-term benefits like fewer complications. The absolute risk reduction for diabetes complications was not reported.
To examine the acute effects of reduced-exertion high-intensity interval training (REHIT) on 24-hour glycaemia in men with type 2 diabetes compared with no exercise, moderate continuous exercise, and high-intensity interval training. No retraction or corrections reported.
In a randomized crossover trial of 11 men with well-controlled type 2 diabetes, a single 10-minute REHIT session (two 20-second all-out sprints) lowered 24-hour mean glucose by an absolute 0.58 mmol/L (95% CI 0.17–0.99; p=0.008) and reduced time in hyperglycaemia (≥9 mmol/L) by an absolute 112 minutes (p=0.002) versus no exercise. Dinner glucose AUC fell by a relative 11% (p<0.05; absolute reduction not reported). MICT showed a nonsignificant absolute 0.37 mmol/L reduction (p=0.08); HIIT did not significantly lower mean glucose but reduced hyperglycaemia time by an absolute 125 minutes (p=0.04).
Methods Used
Randomized, four-trial crossover; 11 men with type 2 diabetes (age 52±6 years; BMI 29.7±3.1 kg/m²; HbA1c 7.0±0.8%) completed no exercise (CON), 30-min moderate continuous cycling (MICT), 10×1-min HIIT, and 2×20-s sprint REHIT in random order, separated by ≥5 days, with standardized diet and continuous glucose monitoring for 24 hours.
Main Finding
A single 10-minute REHIT session lowered 24-hour mean glucose by an absolute 0.58 mmol/L (95% CI 0.17–0.99; p=0.008) and reduced time in hyperglycaemia by an absolute 112 minutes (p=0.002) versus no exercise in 11 men with well-controlled type 2 diabetes. Dinner glucose AUC was 11% lower relative (p<0.05); absolute AUC reduction not reported. MICT showed a nonsignificant absolute 0.37 mmol/L reduction (p=0.08); HIIT did not significantly lower mean glucose but reduced hyperglycaemia time by an absolute 125 minutes (p=0.04).
Confidence Level
Low-to-moderate; randomized crossover and standardized diet are strengths, but n=11 men, acute single session, 24-hour only, well-controlled diabetes, no long-term outcomes, and some comparisons not significant.
Study Flags
Red Flags
- •Small sample (n=11 men), acute single session, no long-term clinical outcomes
- •Participants had well-controlled type 2 diabetes, limiting generalizability
- •Some exercise conditions (MICT, HIIT) showed nonsignificant effects on primary glucose outcomes; absolute AUC reduction for dinner not reported
No biological mechanisms were identified in this study. This may be an epidemiological, observational, or survey-based study that reports associations rather than proposing causal biological pathways.
Surprising Findings
REHIT significantly lowered 24-hour mean glucose while HIIT did not, despite HIIT requiring far more time and effort.
Conventional wisdom says more high-intensity exercise should produce larger glucose benefits.
Practical Takeaways
If you have well-controlled type 2 diabetes and limited time, discuss with your doctor whether a 10-minute REHIT session (two 20-second all-out bike sprints within 10 minutes) could fit your routine.
RCT reviewsReviews of RCTs (Meta-analyses)
Max 100Randomized TrialsRandomized Trials
Max 90Reviews of Cohort StudiesReviews of Cohort Studies
Max 85Cohort StudiesCohort Studies
Max 72Reviews of Case-Control StudiesReviews of Case-Control Studies
Max 63Case-Control StudiesCase-Control Studies
Max 58Cross-Sectional & Case SeriesCross-Sectional & Case Series
Max 50Expert OpinionExpert Opinion
Max 565 / 100
Probability of being correct
Participants are randomly assigned to treatment or control groups, minimizing bias. The gold standard for testing whether an intervention causes an effect.
Human RCT
Subject
Moderate probability
on the GRADE evidence scale
This study tested a very short burst of exercise in 11 men with diabetes. Because the men were randomly assigned to different exercise orders, we can be fairly confident that the exercise changed their blood sugar for that day, but it doesn't tell us about long-term health or whether it works for everyone.
The study has a COI section but no disclosure was found. A small penalty has been applied.
Strengths
- Randomized four-trial crossover design with within-subject control reduces confounding.
- Inclusion of a no-exercise control condition allows comparison to usual daily glycaemia.
- Standardized diet and meal timing across all trials.
Weaknesses
- Very small sample size (n=11) increases risk of type II error and imprecision.
- No blinding of participants, though exercise interventions are difficult to blind.
- Acute single-bout design cannot inform long-term glycaemic control or clinical outcomes.
Methodology
Evidence Keywords
Statistical Reporting
Not medical advice. For informational purposes only. Always consult a healthcare professional. Terms
In 11 men with well-controlled type 2 diabetes, one 10-minute REHIT session (two 20-second all-out bike sprints) lowered 24-hour average blood sugar and reduced high-blood-sugar time compared with no exercise.
Research results
In 11 men with type 2 diabetes, one 10-minute REHIT session lowered 24-hour average blood sugar by an absolute 0.58 mmol/L and cut time spent above 9 mmol/L by an absolute 112 minutes (about 1 hour 52 minutes) over 24 hours compared with no exercise. The blood sugar response to dinner was 11% lower relative, but the absolute reduction was not reported. A 30-minute moderate workout (MICT) lowered average blood sugar by 0.37 mmol/L but this was not statistically significant (p=0.08). HIIT did not significantly lower average blood sugar but reduced time above 9 mmol/L by 125 minutes.
What this means - more context
For a man with well-controlled type 2 diabetes, a single 10-minute REHIT session may meaningfully lower average blood sugar and reduce high-blood-sugar time by nearly 2 hours over the next day. However, this was a small, short-term study (11 men, 24 hours) and does not prove long-term benefits like fewer complications. The absolute risk reduction for diabetes complications was not reported.
To examine the acute effects of reduced-exertion high-intensity interval training (REHIT) on 24-hour glycaemia in men with type 2 diabetes compared with no exercise, moderate continuous exercise, and high-intensity interval training. No retraction or corrections reported.
In a randomized crossover trial of 11 men with well-controlled type 2 diabetes, a single 10-minute REHIT session (two 20-second all-out sprints) lowered 24-hour mean glucose by an absolute 0.58 mmol/L (95% CI 0.17–0.99; p=0.008) and reduced time in hyperglycaemia (≥9 mmol/L) by an absolute 112 minutes (p=0.002) versus no exercise. Dinner glucose AUC fell by a relative 11% (p<0.05; absolute reduction not reported). MICT showed a nonsignificant absolute 0.37 mmol/L reduction (p=0.08); HIIT did not significantly lower mean glucose but reduced hyperglycaemia time by an absolute 125 minutes (p=0.04).
Methods Used
Randomized, four-trial crossover; 11 men with type 2 diabetes (age 52±6 years; BMI 29.7±3.1 kg/m²; HbA1c 7.0±0.8%) completed no exercise (CON), 30-min moderate continuous cycling (MICT), 10×1-min HIIT, and 2×20-s sprint REHIT in random order, separated by ≥5 days, with standardized diet and continuous glucose monitoring for 24 hours.
Main Finding
A single 10-minute REHIT session lowered 24-hour mean glucose by an absolute 0.58 mmol/L (95% CI 0.17–0.99; p=0.008) and reduced time in hyperglycaemia by an absolute 112 minutes (p=0.002) versus no exercise in 11 men with well-controlled type 2 diabetes. Dinner glucose AUC was 11% lower relative (p<0.05); absolute AUC reduction not reported. MICT showed a nonsignificant absolute 0.37 mmol/L reduction (p=0.08); HIIT did not significantly lower mean glucose but reduced hyperglycaemia time by an absolute 125 minutes (p=0.04).
Confidence Level
Low-to-moderate; randomized crossover and standardized diet are strengths, but n=11 men, acute single session, 24-hour only, well-controlled diabetes, no long-term outcomes, and some comparisons not significant.
Study Flags
Red Flags
- •Small sample (n=11 men), acute single session, no long-term clinical outcomes
- •Participants had well-controlled type 2 diabetes, limiting generalizability
- •Some exercise conditions (MICT, HIIT) showed nonsignificant effects on primary glucose outcomes; absolute AUC reduction for dinner not reported
No biological mechanisms were identified in this study. This may be an epidemiological, observational, or survey-based study that reports associations rather than proposing causal biological pathways.
Surprising Findings
REHIT significantly lowered 24-hour mean glucose while HIIT did not, despite HIIT requiring far more time and effort.
Conventional wisdom says more high-intensity exercise should produce larger glucose benefits.
Practical Takeaways
If you have well-controlled type 2 diabetes and limited time, discuss with your doctor whether a 10-minute REHIT session (two 20-second all-out bike sprints within 10 minutes) could fit your routine.
RCT reviewsReviews of RCTs (Meta-analyses)
Max 100Randomized TrialsRandomized Trials
Max 90Reviews of Cohort StudiesReviews of Cohort Studies
Max 85Cohort StudiesCohort Studies
Max 72Reviews of Case-Control StudiesReviews of Case-Control Studies
Max 63Case-Control StudiesCase-Control Studies
Max 58Cross-Sectional & Case SeriesCross-Sectional & Case Series
Max 50Expert OpinionExpert Opinion
Max 565 / 100
Probability of being correct
Participants are randomly assigned to treatment or control groups, minimizing bias. The gold standard for testing whether an intervention causes an effect.
Human RCT
Subject
Moderate probability
on the GRADE evidence scale
This study tested a very short burst of exercise in 11 men with diabetes. Because the men were randomly assigned to different exercise orders, we can be fairly confident that the exercise changed their blood sugar for that day, but it doesn't tell us about long-term health or whether it works for everyone.
The study has a COI section but no disclosure was found. A small penalty has been applied.
Strengths
- Randomized four-trial crossover design with within-subject control reduces confounding.
- Inclusion of a no-exercise control condition allows comparison to usual daily glycaemia.
- Standardized diet and meal timing across all trials.
Weaknesses
- Very small sample size (n=11) increases risk of type II error and imprecision.
- No blinding of participants, though exercise interventions are difficult to blind.
- Acute single-bout design cannot inform long-term glycaemic control or clinical outcomes.
Methodology
Evidence Keywords
Statistical Reporting
Scoring
How strong is this study?
The study was well-controlled because everyone ate the same meals and wore a glucose monitor, but it only included 11 men and the participants knew which exercise they were doing. That means the results are promising but not final; larger studies are needed to confirm them.
0 / 100
- COI disclosureconflicts of interest not disclosed
- Data availabilitydata not shared
- Code availabilitycode not shared
58 / 100
- Randomization+20/20
- Blindingblinding unclear
- Control group+15/15
- Sample size (n=11)+1.1/20
- Follow-up+10/10
100 / 100
100 / 100
- P-values+15/15
- Effect size+20/20
- Confidence intervals+15/15
- Pre-registration+15/15
Each component is scored out of 100 and then capped by the study design — a case series cannot reach the ceiling a randomised trial can, however well it is reported.
Where it sits
RCT reviewsReviews of RCTs (Meta-analyses)
Max 100Randomized TrialsRandomized Trials
Max 90Reviews of Cohort StudiesReviews of Cohort Studies
Max 85Cohort StudiesCohort Studies
Max 72Reviews of Case-Control StudiesReviews of Case-Control Studies
Max 63Case-Control StudiesCase-Control Studies
Max 58Cross-Sectional & Case SeriesCross-Sectional & Case Series
Max 50Expert OpinionExpert Opinion
Max 565 / 100
Probability of being correct
Participants are randomly assigned to treatment or control groups, minimizing bias. The gold standard for testing whether an intervention causes an effect.
This design can establish causation. The randomized crossover design with a no-exercise control supports causal inference for acute effects of REHIT on 24-h glycaemia in this sample. However, the very small sample (n=11), lack of blinding (though exercise interventions are difficult to blind), multiple comparisons, and acute single-bout design limit the strength and generalizability of causal claims. Causation can be inferred for short-term glycaemic changes, but not for long-term outcomes such as HbA1c, complications, or cardiovascular risk.
No Conflicts
No conflicts of interest identified
No conflicts of interest or funding sources were disclosed in the provided text.
The provided text lacks a conflict of interest or funding statement. The study was registered (NCT03082859) and approved by an ethics committee. No author affiliations are listed, so potential industry ties cannot be assessed. Commercial devices (Medtronic, Roche, Lode, Cosmed, Actiheart) are mentioned, but no funding or conflicts are declared.
Standing
The people behind it
The researchers who wrote the study this analysis is built on.
Authored by
7 researchersIf this is your work, this is how we attribute it on Fit Body Science. Richard S. Metcalfe is listed as the lead author.
- Richard S. MetcalfeLeadCorresponding