HIIT & BDNF Release

HIIT & BDNF Release

In public discussion, study results are often oversimplified. Here is the classification: what the data show, where methodological limits lie, and what this means for practice.

Comparison of moderate continuous training and HIIT on plasma BDNF levels.

1. The Study Data: Methodology & Sample

Level of evidence: High. Crossover study.

2. The Key Results in Numbers

• Comparison of moderate continuous training and HIIT on plasma BDNF levels.

3. The Dose-Response Curve: How Much Is Optimal?

The central question is: how intensely and how frequently must one train for the BDNF increase in the blood to be measurable? The present crossover study compares moderate continuous training with HIIT and suggests that intensity is the decisive lever – not training volume alone.

Explained in layman's terms:

• Intensity: HIIT means short, very hard peaks of exertion (e.g., 80–95% of maximum heart rate) alternating with easy recovery phases. Precisely these peaks appear to trigger BDNF release more strongly than steady, moderate running.
• Volume: The total load in HIIT often remains lower than in continuous training – fewer minutes, but higher stimulus density.
• Frequency: For neuroplastic effects, regularity counts. 2–3 HIIT sessions per week are considered a practicable framework; more is not automatically better.
• Left/Middle/Right: "Left" = easy movement (walking, cycling in the base range), "Middle" = moderate continuous training, "Right" = HIIT peaks. The BDNF effect sits mainly at the right edge – but only if the base (left/middle) is right.

Quick-reference table:

Key takeaway: It is not the longest session that counts, but the most intense stimulus – dosed in moderation and regularly.

Note: For the specific effect sizes and measurement time points, please check the original study; the primary source does not report a complete dose-response curve.

4. Critical Appraisal: Strengths & Methodological Weaknesses

Strengths of the Study

• High. Crossover study.

Methodological Weaknesses

• Note observational/methodological limits (correlation ≠ causation, confounders possible).

5. Counter-Studies & Supplementary Evidence

• Very high cardiovascular load; not suitable for untrained cardiac patients without a checkup.

6. Practical Transfer: What Does This Mean for Your Training Plan?

In the study, HIIT triggers a significantly higher increase in the brain-derived growth factor BDNF than moderate continuous training. In practice, this means: use intensity in a targeted way, but do not make it a permanent state.

Example A — Weekly Plan

Example B — Execution & Coaching Cues

• Warm-up: 5–8 min easy, to prepare heart rate and musculature.
• Intervals: "Give everything, then recover in a controlled way" – the recovery phase is part of the stimulus, not lost time.
• Breathing: Short and controlled during the peaks, breathe deeply during recovery.
• Stop criterion: Stop immediately if you experience dizziness, nausea, or unusual pressure in the chest.
• Cool-down: 5 min of jogging out so that the heart rate normalizes.

Example C — Microcycle (4 Weeks)

• Week 1: 1 HIIT session, 2 easy sessions – acclimation.
• Week 2: 2 HIIT sessions, 1 moderate session.
• Week 3: 2 HIIT sessions, 1 moderate, 1 easy – slightly increase the load.
• Week 4: Deload – only 1 HIIT session, the rest easy, to ensure recovery.

Ideal: 2–3 HIIT sessions per week, embedded in a solid base of easy and moderate sessions.

Good enough: 1 HIIT session per week plus regular movement – the BDNF stimulus also arises here.

First step: Plan a single HIIT session this week (e.g., 4×4 min) and stay easy the rest of the week.

Conclusion

Intense peaks of exertion particularly strongly promote neuroplastic processes in the brain.

Reference / Primary Source

• Jeon, Y. K., & Ha, C. H. (2017). The effect of exercise intensity on brain derived neurotrophic factor and memory in adolescents. J Exerc Rehabil.
• https://pubmed.ncbi.nlm.nih.gov/29165142/