The Brain Benefit Of Exercise May Come Down To Two Key Molecules
Ever notice how a walk can clear your head after a long day, or how you feel more focused after a workout?
Exercise doesn't just work your muscles. It also changes what's happening in your brain, which may help explain why regular movement is linked to better cognitive health as we age.
A recent review of exercise research1 looked at how different forms of exercise affect the brain across the lifespan. The researchers focused on two molecules, BDNF and IGF-1, that may help explain some of these benefits.
The bigger takeaway is pretty simple: cardio and strength training may support the brain in different ways.
About the review
The authors brought together findings from human studies, observational research, and animal studies to examine how exercise affects the brain throughout life.
They focused on several biological changes linked to exercise, including BDNF and IGF-1. You don't need to know the finer details of either molecule to understand why they're relevant.
BDNF helps support healthy brain cells and plays an important role in learning and memory, while IGF-1 is involved in maintaining and supporting the brain.
The review then looked at how different types of exercise were connected to these molecules and whether factors such as workout frequency, intensity, and duration made a difference.
Cardio & strength training may benefit the brain differently
Aerobic exercise had the strongest connection with BDNF. The review found that challenging cardio, including activities such as running, cycling, and brisk walking, was associated with greater increases in this brain-supporting molecule.
The research pointed to aerobic exercise at roughly 65% or more of your max effort, two to three times a week, with sessions lasting at least 40 minutes, as a pattern associated with a stronger BDNF response.
Strength training showed a different relationship with IGF-1. In this case, how often you trained appeared to matter more than exactly how heavy or how long you trained. The review pointed to resistance training at least three times a week.
And there may be benefits beyond these molecules.
The research included in the review linked aerobic exercise with changes related to memory and mood, while resistance training has been associated with better memory, attention, and executive function in older adults with mild cognitive impairment.
Some of those benefits remained a year after the training program ended.
Build a brain-supporting workout routine
You don't need to turn your workouts into a science experiment. But if supporting your brain is one of your goals, this review gives you a reason to make room for both cardio and strength training.
- Get your heart rate up: Aim for challenging aerobic exercise around 65% or more of your max effort, two to three times a week for at least 40 minutes. Brisk walking, cycling, swimming, or running can all count.
- Keep strength training in the mix: Aim for resistance training at least three times a week. Free weights, machines, resistance bands, and bodyweight exercises all work. Consistency appeared to matter more than the exact weight or workout length for the IGF-1 pathway.
These aren't rigid prescriptions, and the review included different types of evidence. Think of them as a framework rather than a perfect formula.
The takeaway
Your brain may benefit from the combination of cardio and strength training, not just exercise in general. Making room for both gives you a simple way to support brain health while building a stronger, more capable body.