# Effectiveness of short sprint interval training in women with major depressive disorder: a proof-of-concept study PMID: 38686128 Journal: Frontiers in psychiatry Published: 2024 Authors: Ribeiro JA, Schuch FB, Tonello L, Meneghel Vargas KF, Oliveira-Junior SA, Müller PT, Boullosa D ## Question Does a 2-week short sprint interval training protocol improve depressive symptoms, physical fitness, body composition, and incidental physical activity in adult women with major depressive disorder? ## Summary This proof-of-concept randomized trial tested six very short sprint interval cycling sessions over 2 weeks in adult women with moderate or severe major depressive disorder. Compared with control, the sSIT group had significant reductions in HAM-D21 depressive symptom scores and improvements in maximum aerobic power, total test time, countermovement jump, body fat percentage, and pedometer-measured steps. The trial was very small, short, and limited to women with unipolar MDD, so findings need confirmation. ## Population - Adult women with moderate or severe major unipolar depressive disorder who completed follow-up. - Sample size: 17 - Age: Control 47.0 +/- 10.3 years; sSIT 37.1 +/- 12.1 years. - Sex: All women. - Fitness level: Physically inactive; excluded regular exercisers. - Health status: Moderate or severe MDD; participants maintained antidepressant/anxiolytic medications. ## Methodology - Proof-of-concept randomized controlled trial with pre- and post-intervention assessments. - 4-week study period: pre-intervention assessment week, 2-week intervention, post-intervention assessment week - Clinical and exercise testing/training setting at Federal University of Mato Grosso do Sul and associated institutions in Brazil - Randomized and controlled study design. ## Protocol - Short sprint interval training. - Modality: Cycle ergometer. - Work intervals: 5 seconds all-out at maximum possible cadence. - Recovery: 30-45 seconds active recovery at 50 W and about 60 rpm. - Sets or repetitions: 3-12 sprints per session. - Intensity: Sprint load equal to maximum aerobic power achieved during incremental test; all-out cadence. - Session duration: 6-10 minutes. - Frequency: 3 times per week with 24-48 hours rest between sessions. - Program length: 2 weeks. - Progression: Linear progression in sprint count with individualized patient-selected number of sprints and reduction in final session. - Control condition. - Program length: 2-week intervention period within a 4-week study. ## Outcomes ### HAM-D21 depressive symptoms Status: improved HAM-D21 scores decreased in the sSIT group and not in the control group. sSIT pre 24.67 +/- 8.29, post 16.89 +/- 10.12, delta -34.30% +/- 32.26%; control pre 22.50 +/- 6.97, post 24.00 +/- 8.30, delta 5.46% +/- 24.66; group x time F=14.332, p=0.002; sSIT pre-post p<0.001. ### Maximum aerobic power Status: improved Maximum aerobic power improved in the sSIT group compared with control. sSIT 141 +/- 19 W to 155 +/- 21 W; control 119 +/- 16 W to 118 +/- 16 W; interaction p=0.016; delta p=0.015. ### Total time in incremental test Status: improved Total incremental test time improved in sSIT and decreased slightly in control. sSIT 569 +/- 75 s to 653 +/- 101 s; control 514 +/- 51 s to 505 +/- 46 s; interaction p<0.001; delta p=0.001. ### Body fatness Status: improved Body fat percentage decreased in the sSIT group and increased in control. sSIT 32.4% +/- 4.5 to 29.9% +/- 4.1; control 34.7% +/- 1.8 to 35.6% +/- 1.9; interaction p<0.001; delta p<0.001. ### Steps Status: improved Four-day pedometer steps increased in sSIT and decreased in control. sSIT 18,843 +/- 8,781 to 24,017 +/- 10,882; control 13,343 +/- 9,511 to 10,181 +/- 6,905; interaction p=0.009. ### Handgrip strength and several anthropometric measures Status: no clear change Handgrip strength, body mass, BMI, waist circumference, and abdominal circumference did not show significant intervention effects. Reported interaction p values were non-significant for these variables. ## Practical Insights - Very short sprint intervals can be structured as 5 seconds hard with 30-45 seconds active recovery, keeping total session time near 6-10 minutes. - Low-volume sprint training may be promising for populations where lack of time and low adherence are major barriers. - Clinical sprint protocols need screening because all-out efforts and maximal testing were used. - Exact replication requires a cycle ergometer and maximum aerobic power testing. ## Limitations - Energy intake was not controlled. - Only unipolar MDD patients were included. - Only women were studied. - VO2max was not measured at follow-up because of metabolic cart technical issues. - Maximum aerobic power and total test time were used as aerobic fitness indices instead of VO2max. - Limited sample size. - Short intervention and no longer follow-up. ## Safety And Adherence - PAR-Q was used to identify risks and contraindications before maximal testing and high-intensity exercise. - Participants with conditions preventing exhaustive test or exercise program participation were excluded. - No adverse events were reported in the article text. ## Original Sources - [PubMed](https://pubmed.ncbi.nlm.nih.gov/38686128/) (pubmed) - [DOI](https://doi.org/10.3389/fpsyt.2024.1356559) (doi) - [PMC full text](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11056580/) (full text) ## Agent Guidance Preserve the paper-level scope of this note. Do not generalize beyond the population, protocol, measured outcomes, and limitations above.