How to Exercise For Improved Cognitive Function | Dr. Tommy Wood & Dr. Andrew Huberman

Key takeaways: how exercise supports cognitive function (immediately and long-term)

Short bouts of non-exhausting exercise can boost cognition right away

• Moving your body and increasing effort generally raises arousal/alertness
• This can improve learning and retrieval, partly via stress/arousal chemistry (e.g., catecholamines) and related signaling

Avoid truly exhausting workouts if you need your brain “online” afterward

• Very high-output efforts (e.g., pushing to “flat-out” levels like a hard 2K erg test or brutal CrossFit-style sessions) can leave you mentally impaired afterward
• A practical approach is to leave some capacity unused, for example:
  • Reduce volume (or keep total hard sets modest)
  • Example cited: low-volume, high-intensity lifting such as ~2 sets per exercise, 2–3 exercises per muscle group
  • Note: going closer to failure or doing too much volume can reduce performance later in the day
• This matters most if you’re doing hard cognitive work soon after (writing, analyzing data, reading, etc.)

A “best evidence” timing/intensity sweet spot for cognition right after exercise

• Meta-analyses cited suggest the strongest evidence for immediate cognitive support is:
  • ~20–30 minute jog (moderate exertion; not maximal)

Why it works: not just “runner’s high”

• The effect isn’t necessarily from endorphins alone
• Likely contributors include:
  • catecholamines (adrenaline/norepinephrine/dopamine)
  • cortisol (can increase alertness in the short term)
• The core idea: a small shift up the arousal curve is often enough to improve focus and engagement on cognitive tasks

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Self-care / workout planning strategy: match exercise to what you need afterward

Because responses are subjective, the advice becomes practical:

• If you have demanding cognitive tasks afterward (afternoon work/exams):

  • Choose exercise below your “pushing the envelope” level
  • Consider:
    • moderate intensity (e.g., brisk jog), or
    • brief high-intensity bouts with long rests (instead of sustained maximal exertion)
  • Keep volume conservative so you’re not “dragging” later

• If your goal is long-term brain/hippocampal improvement (not just a post-workout boost):

  • Intensity and effort matter more over time
  • High-effort intervals can drive longer-lasting benefits, even if you feel worse immediately afterward

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Long-term brain benefits: aerobic zone work vs high-intensity intervals

Zone 2 aerobic training shows improvements

• Example: brisk walking ~40 minutes, 3x/week for a year (zone 2 effort)
• Outcomes mentioned:
  • increased hippocampal volume
  • increased VO₂ max
  • increased BDNF-related markers (circulating BDNF as a proxy)
  • improved memory

Norwegian “4x4” style HIIT can be even better

• Protocol described:
  • 4 minutes at ~85–95% max heart rate
  • 3-minute rest
  • 4 rounds (Norwegian 4x4)
• Compared groups:
  • low intensity
  • zone 2 treadmill work
  • high-intensity interval training
• Findings mentioned:
  • HIIT improved fitness similarly to zone 2
  • HIIT produced better hippocampal function
  • maintenance of hippocampal structure on MRI
  • benefits reportedly persisted for years after the 6-month intervention

Rebuttal to “avoid cortisol / avoid high intensity”

• The discussion emphasized that:
  • high-intensity work releases more cortisol
  • but the stress response is not automatically harmful for brain outcomes
• In the study, working harder and releasing more cortisol correlated with better hippocampal benefits

Proposed mechanism for why HIIT may help

HIIT may promote brain-supportive signals including:

• myokines (notably lactate signals)
• lactate crossing into the brain
• increased BDNF production, supporting neuroplasticity and hippocampal structure/function

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Presenters / sources

• Dr. Tommy Wood
• Dr. Andrew Huberman