A study in which 64 sedentary older adults (aged 60-88) participated in a 12-week exercise program found that those who engaged in high-intensity interval training (HIIT) saw an improvement of up to 30% in memory performance while participants who engaged in moderate-intensity aerobic exercise saw no improvement, on average.
Moreover, improvements in fitness levels directly correlated with improvement in memory performance.
Participants participated in three sessions per week. A control group engaged in stretching only.
The HIIT protocol included four sets of high-intensity exercise on a treadmill for four minutes, followed by a recovery period. The MICT protocol included one set of moderate-intensity aerobic exercise for nearly 50 minutes.
Participants were assessed using a Mnemonic Similarity task and two tasks that assess executive function. The Mnemonic Similarity Task is highly sensitive to functions carried out by the hippocampus, which is the brain region most affected by exercise, through the creation of new neurons.
An earlier study involving 95 healthy young adults who underwent a 6 week HIIT program also showed significant improvements in this type of memory. Those who experienced greater fitness gains also experienced greater increases in brain-derived neurotrophic factor (BDNF).
Reference:
Kovacevic, A., Fenesi, B., Paolucci, E., & Heisz, J. J. (2019). The effects of aerobic exercise intensity on memory in older adults. Applied Physiology, Nutrition, and Metabolism, 45(6), 591–600. https://doi.org/10.1139/apnm-2019-0495
Heisz, J. J., Clark, I. B., Bonin, K., Paolucci, E. M., Michalski, B., Becker, S., & Fahnestock, M. (2017). The Effects of Physical Exercise and Cognitive Training on Memory and Neurotrophic Factors. Journal of Cognitive Neuroscience, 29(11), 1895–1907. https://doi.org/10.1162/jocn_a_01164
