Posted on May 05, 2017, 6 a.m.
Increasing muscle strength through resistance training improves cognitive function and may prevent dementia
In Australia, a University of Sydney study has linked improved cognitive function with stronger muscles using a steady regime of weightlifting exercises. Published in the Journal of American Geriatrics, the study used a system known as SMART (Study of Mental and Resistance Training). A trial was done on a group of patients age 55 to 68, suffering MCI (mild cognitive impairment). This condition is not as serious as full-blown dementia, as people affected only have mild cognitive symptoms not severe enough to disable them from normal daily life.
People who have MCI though are at high risk of developing dementia or Alzheimer's with 80% going on to develop Alzheimer's disease within 6 years. The World Alzheimer Report 2016 has reported that 47 million people globally are affected by dementia related diseases, with an expected three-fold increase by the year 2050. The cost of care is high for these patients, with a focus only on extending the quality of life for those living with dementia.
Weight Training Improves Cognitive Functions
The aim of the study was to measure the effects of different physical and mental activities on the human brain. Researchers examined 100 people affected by MCI. They were divided into four groups, and assigned the activities as seen below:
- weightlifting exercises
- seated stretching exercises
- real cognitive training on a computer
- placebo training on a computer
The weightlifting trial lasted for 6 months with exercising done twice a week. As the participants got stronger, they increased the amount of weight for each exercise. The exercises were done while trying to maintain 80% or greater at their peak strength.
Surprisingly, only the weight training activity demonstrated a measured improvement in brain function. The stretching exercises, cognitive training, and placebo training did not yield any results. This proved a link between muscle strength gained through physical training and the improved cognitive functions. According to Doctor Yorgi Mavros, lead author of the study, there was a clear relationship between mental functions and increased muscular strength. And the stronger the muscles got the greater the mental improvement.
In an earlier study, researchers scanned the brains of older adults after 6 months of weight training. The results mirrored the SMART trial with measured brain growth. Although previous studies have been done that show links between exercise and improved brain functions, the SMART system went into detail on the types of exercise required to get the best results. This study was a first in showing evidence of a link between strength training and improved cognitive functions for people with MCI who were 55 or older.
Delaying or Stopping Aging in the Brain
People increase their chances of brain impairment by not exercising. Exercise can help prevent dementia and Alzheimer's disease, but also improves cardiovascular health and some other cognitive processes like multitasking.
Doctor Mavros is a strong advocate for encouraging resistance exercises as people start to grow older. The result could be a much healthier aging population. Mavros stressed the need for exercising at least 2-3 time per week at a high enough intensity in order to get the maximum cognitive benefits.
Professor Maria Fiatarone Singh of the University of Sydney wants to discover the underlying process of muscle growth and brain growth and its effect on cognitive performance. The next step is deciding how to prescribe optimal exercise programs to individuals with mild cognitive impairment, and to those who want to prevent MCI.
The authors of the study pointed out that the mechanism behind weight training and improving cognitive impairment has not yet been determined and future study may uncover the secret of delaying or even stopping degenerative aging effects of the brain.
Mediation of cognitive function improvements by strength gains after resistance training in older adults with mild cognitive impairment: Outcomes of the study of mental and resistance training, Yorgi Mavros et al., Journal of the American Geriatrics Society, doi: 10.1111/jgs.14542, published online 24 October 2016, abstract.