High-intensity interval training may be an effective strategy to counteract age-related declines in memory.

August 10, 2020

Katie Kowalski, DPT

School of Kinesiology, Western University, London, Ontario, Canada

Take home message

  • 12-weeks of high-intensity interval training performed 3 times per week leads to greater improvements in memory than moderate-intensity continuous training in older adults.
  • Given the relatively inexpensive nature of exercise as a therapeutic intervention, high-intensity interval training may be an effective strategy to counteract age-related declines in memory.

Background 

  • Due to changes in brain structure and function, older adults often experience a decline in memory and difficulty performing challenging cognitive tasks.
  • Aerobic exercise, such as walking or cycling, slows the decline of structural changes in the brain and leads to improved brain function, such as memory.
  • However, the optimal intensity of aerobic exercise to stimulate these structural and functional brain changes in older adults is unknown.

How the study was done

39 females and 25 males, aged 60-88 years, participated in the study. All participants were healthy, did not have any physical or cognitive impairments and were previously sedentary.

Participants were split into three exercise groups, which met 3 times per week for 12 weeks:

  • High-intensity interval training: After a warm-up, participants walked four 4-min intervals on a treadmill at 5% grade and at a speed that increased heart rate to 90-95% of peak. Intervals were separated by 3-min of active recovery walking with a target heart rate of 50-70% peak.
  • Moderate-intensity continuous training: After a warm-up, participants walked on a treadmill at 0% grade continuously for 47-min at 70-75% of peak heart rate.
  • Stretching: Participants performed 30-min of a whole-body standing and sitting stretching routine designed for older adults.

Before and after the exercise intervention, all participants performed an exercise test to measure aerobic fitness and computer tasks to evaluate memory and attentional processing, which is the ability to selectively concentrate on a task. Researchers assessed the change in aerobic fitness, memory and attentional processing in response to the exercise intervention.

What the researchers found

  • Aerobic fitness increased in both the high-intensity interval and moderate-intensity continuous training groups. Aerobic fitness in the stretching group did not change.
  • Memory improved only in the high-intensity interval training group after the exercise intervention. Participants with the greatest increase in aerobic fitness had the greatest improvement in memory.
  • Small improvements in attentional processing occurred in both high-intensity interval and moderate-intensity continuous training groups.

Conclusion

  • A 12-week high-intensity interval training program improves memory and aerobic fitness in older adults.
  • Participants with the greatest improvements in aerobic fitness had the greatest improvements in memory.
Reference: Kovacevic A, Fenesi, B, Paolucci E, Heisz, JJ. The effects of aerobic exercise intensity on memory in older adults. Appl Physiol Nutr Metab. 2020; 45:591-600.