When we think about improving mental performance, we usually focus on what happens in the mind: better focus, stronger habits, emotional control, or learning how to perform under pressure.

But there is another piece of the performance puzzle that is easy to overlook: Your body.

Physical activity doesn't just affect how fit you are. Research increasingly suggests that exercise can also positively influence cognitive performance (Erickson et al., 2019) — including some of the mental abilities we rely on when making decisions, adapting to changing situations, and staying focused on what matters.

The Mental Skills Behind High Performance

Every day, your brain has to filter distractions, hold relevant information in mind, resist impulses, and adjust when circumstances change. Psychology groups several of these abilities under the term executive functions.

Three important components are:

Inhibition — resisting impulses and ignoring distractions.

Working memory — holding and using relevant information in the short term.

Cognitive flexibility — adapting your thinking and behavior when circumstances change.

You probably don't think about these abilities while you're working, competing, trading, or playing poker. But you're using them constantly. When the original plan stops working and you need to adjust, that's cognitive flexibility. When you ignore a distraction and stay with the task, that's inhibition. When you keep several pieces of information in mind before making a decision, that's working memory. These abilities form part of the foundation on which performance is built.

Why Exercise Can Improve the Way Your Brain Performs

During exercise, blood flow and oxygen delivery increase, while the release of neurotransmitters and growth factors involved in brain function and neuroplasticity is stimulated. One particularly interesting factor is BDNF (brain-derived neurotrophic factor), a protein involved in neuronal health, learning and the brain's ability to adapt.These mechanisms may help explain why regular exercise has been associated with improvements in executive functions.

Does Training Harder Improve Your Cognitive Performance Even Further?

One particularly interesting area of this research is High-Intensity Interval Training (HIIT). HIIT alternates short periods of very intense exercise with periods of recovery. Compared with traditional moderate-intensity endurance training, it creates a very different physical stimulus. The interesting question is whether that difference also matters for the brain.

In one six-week study (Mekari et. al, 2020), young adults performed either HIIT or moderate continuous endurance training three times per week. Both groups improved their physical fitness. Also both forms of exercise showed signs of benefiting inhibitory control. But when researchers looked more closely at cognitive performance, something particularly interesting emerged:

The HIIT group showed improvements in tests involving cognitive flexibility. So participants also became better at certain tasks requiring them to switch and adapt their thinking.

But why might training at a higher intensity have this effect?

HIIT repeatedly pushes the body toward high levels of activation before allowing brief periods of recovery. Higher-intensity exercise can produce stronger acute physiological responses involving factors associated with brain adaptation, including BDNF.

There may also be a functional similarity between HIIT and cognitive flexibility:

push → recover → adjust → push again.

Instead of maintaining one constant workload, your nervous system repeatedly has to adapt to rapidly changing demands. That makes HIIT an interesting candidate for improving cognitive flexibility — the ability to quickly shift your thinking and behavior when circumstances change.

Why Cognitive Flexibility Matters

Imagine you're executing a strategy and suddenly receive new information. Your original plan is no longer optimal. Do you recognize it quickly and adapt? Or do you remain mentally attached to the decision you've already made? This matters in almost every high-performance environment.

An athlete has to react when competition doesn't unfold according to plan. A poker player has to continuously adjust to opponents, game dynamics, and incomplete information. A trader has to process changing market conditions without becoming emotionally attached to an existing position. And in everyday professional life, priorities, problems, and information constantly change.

Performance isn't just the ability to execute a plan. It's the ability to recognize when the plan needs to change. That's why cognitive flexibility is so valuable.

Does That Mean HIIT Makes You Smarter?

Not quite. The evidence needs to be interpreted carefully. Research on longer-term HIIT interventions and executive functions — particularly in young, healthy adults — is still relatively limited. Not every cognitive ability consistently improves, and studies don't always produce identical results.

The research reviewed did not establish that HIIT is universally superior to moderate endurance training across inhibition, working memory, and every other aspect of cognition. The strongest emerging signal was more specific:

HIIT may have particular potential for improving cognitive flexibility. That's promising — but it's not a reason to claim that harder workouts automatically create a better brain. It's a reason to look at physical training as another potential tool for mental performance.

Your Brain Doesn't Perform in Isolation

This leads to a broader lesson that matters far beyond HIIT:

Mental and physical performance aren't separate systems.

How you think, focus, make decisions, and respond to pressure doesn't happen independently of your physical state. Exercise is therefore more than something you do for your appearance or cardiovascular health. It can be part of your performance system.

You don't necessarily need to spend hours training every day. And more intensity isn't automatically better. The important shift is understanding that improving your physical capacity may have benefits that extend beyond the gym.

When you're designing your routine for better mental performance, don't just ask:

“How can I train my mind?”

Also ask:

“How can I create a body that helps my mind perform?”

Because better performance might start in your head — but your body can help you get there.

Sources:

1. Diamond, A. (2013). Executive functions. Annual Review of Psychology, 64, 135–168. https://doi.org/10.1146/annurev-psych-113011-143750

2. Erickson, K. I., Hillman, C., Stillman, C. M., et al. (2019). Physical activity, cognition, and brain outcomes: A review of the 2018 Physical Activity Guidelines. Medicine & Science in Sports & Exercise, 51(6), 1242–1251. https://doi.org/10.1249/MSS.0000000000001936

3. Gilson, D., Andersson, D., Papinczak, Z. E., et al. (2023). High intensity and sprint interval training, and work-related cognitive function in adults: A systematic review. Scandinavian Journal of Medicine & Science in Sports, 33(6), 814–833. https://doi.org/10.1111/sms.14349

4. Inoue, D. S., Monteiro, P. A., Gerosa-Neto, J., et al. (2020). Acute increases in brain-derived neurotrophic factor following high or moderate-intensity exercise is accompanied with better cognition performance in obese adults. Scientific Reports, 10, 13493.

5. Mekari, S., Earle, M., Martins, R., et al. (2020). Effect of high intensity interval training compared to continuous training on cognitive performance in young healthy adults: A pilot study. Brain Sciences, 10(2), 81. https://doi.org/10.3390/brainsci10020081

6. Tsukamoto, H., Suga, T., Takenaka, S., et al. (2016). Greater impact of acute high-intensity interval exercise on post-exercise executive function compared to moderate-intensity continuous exercise. Physiology & Behavior, 155, 224–230. https://doi.org/10.1016/j.physbeh.2015.12.021

7. Wu, Q., Niu, X., Zhang, Y., Song, J., & Chi, A. (2023). A comparative study of inhibition function between high-intensity interval training and moderate-intensity continuous training in healthy people: A systematic review with meta-analysis. International Journal of Environmental Research and Public Health, 20(4), 2859.