Enhancing Brain Health: The Role of Zone 2 and Zone 5 Cardio

In recent years, zone 2 cardio workouts have gained significant popularity, especially among midlife women. Characterized as the second least-intense exercise level on a 1 to 5 scale, zone 2 workouts involve elevating the heart rate to 60%-70% of its maximum capacity. This moderate intensity is conducive to maintaining low stress levels in the body, avoiding the cortisol spikes often associated with higher-intensity workouts. According to Louisa Nicola, MMed, a neurophysiologist studying Alzheimer’s disease in women, there are substantial benefits to occasionally increasing your exercise intensity to zone 5—approximately 90% of your maximum heart rate—particularly for brain health.

The Brain Benefits of Cardio

Any form of physical activity can provide valuable brain-boosting benefits, such as:

• Reducing inflammation
• Enhancing blood circulation, thus delivering more oxygen and nutrients to the brain
• Stimulating the release of proteins that support brain cell growth and strengthen neural connections

Higher intensity cardio, specifically zone 5, amplifies these positive effects and enables unique benefits associated with increased effort levels.

Research Insights on Zone 5 Workouts

A 2024 study involving older adults indicated that brief intervals of zone 5 cardio combined with recovery periods could lead to improved memory performance and reduced age-related shrinkage in the brain’s memory center. In another relevant study from 2020, high-intensity interval training (HIIT) was shown to enhance cognitive flexibility in older adults, allowing them to switch between mental tasks more efficiently. These findings highlight the potential for zone 5 cardio to help maintain cognitive function.

Why High-Intensity Cardio Matters for Cognitive Health

Engaging in high-intensity exercise increases your VO₂ max—the maximum rate of oxygen consumption during exercise—which correlates with improved cardiorespiratory fitness. Nicola notes that the increase in blood flow to the brain during high-intensity training can notably benefit overall brain health, as it requires a consistent supply of oxygen and nutrients to function optimally. Studies have established a link between higher VO₂ max levels and better outcomes in working memory, decision-making abilities, processing speed, and a lowered risk of developing dementia.

Considerations for Midlife Women

This information is particularly significant for women in perimenopause. Changes in estrogen levels can lead to decreased muscle mass and overall fitness levels. If physical activity, especially high-intensity training, isn’t prioritized during this period, there is a heightened risk for cognitive decline, as explained by Nicola. Maintaining an active lifestyle can help mitigate these risks.

In summary, both zone 2 and zone 5 cardio provide essential benefits for maintaining not just physical health but also cognitive function, especially for those in midlife. Incorporating a variety of intensities into your workout routine may be a strategic approach to supporting overall brain health.