This Type Of Workout May Give Your Brain An Unexpected Advantage
Ever find yourself staring at a question you know the answer to, but your brain just won't respond fast enough?
Processing speed, or how quickly your brain takes in and responds to information, plays a role in everyday mental tasks. And exercise may help give it a boost.
In a recent 12-week HIIT study1, researchers explored how high-intensity interval training affects both physical fitness and working memory in young adults. The results revealed an interesting potential brain benefit, with one important distinction.
About the study
The randomized controlled trial included 120 young adults ages 18 to 25 with overweight or obesity. Of those, 48 completed a 12-week high-intensity interval training (HIIT) program, while 72 continued their usual daily activities.
The HIIT group attended three 60-minute sessions each week, combining bodyweight exercises, running drills, and fitness games.
Researchers tracked changes in weight, BMI, and cardiovascular fitness (VO2 max, a measure of how efficiently the body uses oxygen).
They also tested working memory using the n-back task, which asks participants to remember letters on a screen and identify when one matches an earlier letter. Both response speed and accuracy were measured.
HIIT helped participants respond faster, but not more accurately
After 12 weeks, the HIIT group lost more weight, reduced their BMI more, and improved their cardiovascular fitness compared to the control group.
They also responded faster on the memory test. However, their accuracy didn't improve compared to the control group once researchers accounted for differences in their starting scores.
In short, HIIT appeared to help participants process and respond to information more quickly, but not get more answers right. Speed and accuracy are two distinct aspects of cognitive performance.
Why the findings need a closer look
The study had a notable limitation. Participants were split into uneven groups (48 in HIIT and 72 in the control group) because of scheduling and instructor availability.
The groups also differed at the start. The control group was taller, heavier, fitter, and more accurate on the memory test before the program began.
Although researchers adjusted their analysis to account for these differences, the initial gaps add some uncertainty to the results. Larger studies with more balanced groups are needed to confirm whether HIIT consistently improves reaction time.
How to work HIIT into your routine
Interested in trying HIIT? You don't need to copy the study's full 60-minute sessions to start incorporating intervals into your workouts.
- Start with simple intervals: Alternate a brisk walk with 30 seconds of faster walking, then recover at a comfortable pace.
- Build gradually: As your fitness improves, increase the intensity or duration of your faster intervals.
- Keep your limits in mind: If you're new to intense exercise or have an underlying health condition, check with a health professional before stepping up your workouts.
While HIIT can support cardiovascular fitness, this study didn't establish whether faster reaction times lead to better concentration, decision-making, or performance at work or school.
The takeaway
HIIT could give your brain a little extra training alongside your muscles and heart.
In this study, young adults responded faster on a memory test after 12 weeks of exercise, but their accuracy stayed the same. Whether that translates into everyday cognitive benefits is still an open question.