Whole-body exercise increases cortical oxygenated hemoglobin concentrations with higher intensity in healthy adultsExercise intensity boosts brain blood flow, meta-analysis finds

Behavioural brain research Published June 25, 2026 Study authors: Lammers Carlijn, Hamer Sanne, Ćurčić-Blake Branislava, van der Zee Eddy A, van Heuvelen Marieke J G PubMed ↗ DOI ↗ Editorial oversight: Dr. Lars van Dijk, PhD · Surgical, Procedural & Diagnostic

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Key Takeaway

Note that higher exercise intensity significantly increases cortical oxygenated hemoglobin concentrations in healthy adults.

This meta-analysis synthesized 29 studies to evaluate the impact of all-type whole-body exercise on cortical oxygenated hemoglobin (HbO) concentrations in healthy adults. The analysis included various modalities such as walking, cycling, and coordination exercises ranging from 5 to 60 minutes at low to vigorous intensities.

The primary finding was a significant increase in HbO concentration during exercise compared to baseline (g=0.56; 95% CI: 0.31-0.82). Notably, the magnitude of this increase was significantly stronger as intensity increased, with effect sizes of g=0.24 for low, g=0.64 for moderate, and g=0.92 for vigorous exercise (p < 0.001). Additionally, higher age groups showed stronger HbO concentrations during exercise compared to younger individuals (old: g=0.83; young: g=0.50; p < 0.001).

Short-term postexercise effects were also significantly related to intensity, with vigorous and moderate intensities showing higher effect sizes (g=1.22 and g=1.16, respectively) compared to low intensity (g=-0.04). However, the trend toward an increase in HbO concentration between pre- and postexercise did not reach statistical significance (p=0.058). These results suggest that exercise intensity is a key factor for increasing cerebral oxygenation during and shortly after physical activity.

Want to give your brain a boost? A new analysis of 29 studies shows that whole-body exercise like walking, cycling, or coordination moves increases blood flow to the brain. The effect is stronger when you exercise harder, and it's even more pronounced in older adults.

Researchers looked at levels of oxygenated hemoglobin (HbO) in the brain's cortex during and after exercise. They found that during exercise, HbO concentrations rose significantly compared to rest. The effect was small for low-intensity exercise, moderate for moderate intensity, and large for vigorous intensity. Older adults showed a bigger increase than younger ones.

After exercise, there was a trend toward higher HbO levels, but this didn't reach statistical significance. That means the lasting effect on brain blood flow is less certain. The analysis didn't report any safety issues, but it also didn't track side effects.

This is a meta-analysis, which combines results from many studies. While it can't prove cause and effect, it suggests that exercise intensity matters for brain blood flow. If you're looking to get the most brain benefit, picking up the pace might help.

What this means for you:

Higher intensity exercise boosts brain blood flow more, especially in older adults.

Common questions

What does this study say about exercise and brain blood flow?

This meta-analysis of 29 studies found that whole-body exercise like walking, cycling, or coordination increases oxygenated hemoglobin (HbO) in the brain during exercise. The effect was stronger with higher intensity and in older adults.

Does exercise intensity matter for brain benefits?

Yes. The study found that low-intensity exercise had a small effect (g=0.24), moderate intensity a moderate effect (g=0.64), and vigorous intensity a large effect (g=0.92) on brain blood flow during exercise. So pushing harder may give your brain a bigger boost.

Is this effect different for older versus younger adults?

Yes. The analysis showed that older adults had a stronger increase in brain blood flow during exercise (g=0.83) compared to younger adults (g=0.50). This suggests exercise may be especially beneficial for brain health as we age.

Does exercise increase brain blood flow after you stop?

The study found a trend toward increased oxygenated hemoglobin after exercise, but it did not reach statistical significance (p=0.058). So the evidence for a lasting effect is not strong enough to be certain.

Study Details

Study typeMeta analysis

EvidenceLevel 1

PublishedJun 2026

PMID41967587

View Original Abstract ↓

INTRODUCTION: Exercise benefits cognition, particularly in older adults. During exercise, brain activity may increase blood flow and oxygen delivery. Functional near-infrared spectroscopy (fNIRS) enables the assessment of cortical activity by measuring changes in oxygenated (HbO) and deoxygenated hemoglobin (HbR). This review examined the acute and short-term effects of whole-body exercise on HbO concentration in healthy adults. METHOD: We searched PubMed, Embase and Web of Science for studies involving healthy adults performing any type of whole-body exercise, with fNIRS measurements taken during or shortly after the exercise. We performed multilevel meta-analyses using R studio package Metafor 4.8-0. RESULTS: 29 studies were included in the quantitative analyses. Exercises mainly involved walking, cycling, or coordination (5-60 min, low to vigorous intensity). Overall, HbO concentration increased during exercise versus baseline (pooled standardized mean g=0.56; 95% CI: 0.31-0.82) with no significant relationship with brain region, exercise type, exercise duration or gender (p > 0.05). Acute effects are stronger with increased exercise intensity (low, g=0.24; moderate, g=0.64; vigorous, g=0.92; p < 0.001) and for higher age (old, g=0.83; young g=0.50; p < 0.001). HbO concentration shows a trend towards an increase between pre- and postexercise (pooled standardized mean g=0.61; 95% CI: -0.03-1.2371; p = 0.058). Short-term effects were significantly related to exercise intensity (low, g=-0.04; moderate, g=1.16; vigorous, g= 1.22; p < 0.001), but not to brain area, exercise type, exercise duration or gender (p > 0.05). CONCLUSION: Exercise increases HbO concentration during exercise. Exercise intensity appeared a key factor to increase impact on the brain both during and shortly after exercise.

Whole-body exercise increases cortical oxygenated hemoglobin concentrations with higher intensity in healthy adultsExercise intensity boosts brain blood flow, meta-analysis finds

Common questions

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Whole-body exercise increases cortical oxygenated hemoglobin concentrations with higher intensity in healthy adultsExercise intensity boosts brain blood flow, meta-analysis finds

Common questions

Study Details

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