Strength training trains the brain
When we train our muscles, we also train our brain. The older we get, the faster the body automatically loses muscle and therefore muscle strength. The consequences of this are not only frailty in old age, but also cognitive decline.
As numerous studies have shown, we can build up our muscles with strength training and thus not only positively develop our musculoskeletal system, but also trigger a variety of mechanisms that protect our brain from age-related cognitive decline.
The SMART study
The SMART study was a randomized, double-blind, sham-controlled clinical trial that investigated whether high-intensity strength training can improve cognitive performance in people with Mild Cognitive Impairment (MCI).
The word “sham” comes from the English and means “pretense” or “sham”. While people usually simply take a sugar placebo with pills, sham interventions are used with medical devices or operations.
- The test group: Receives the real treatment (e.g. laser therapy or minor surgery).
- The Sham group: Receives a “sham treatment”. It all looks the same: Patients are taken into the operating room, the equipment whirs, maybe even a superficial incision is made – but the decisive therapeutic step does not take place.
The study included 100 people over the age of 55 with diagnosed MCI. MCI is considered a relevant preliminary stage of neurodegenerative diseases: Those affected have an annual risk of dementia of around 6-10%, compared to only 1-2% in the general population of the same age.
The participants were randomly divided into two groups:
- Intervention group: completed 6 months of high-intensity, progressive strength training. This took place 2-3 times a week and covered large muscle groups, including the leg press, leg extension, leg curl and upper body machines. The training intensity was progressively increased and was around 80% of the 1-RM, i.e. in the clearly effective strength training range.
- Control groupSham training with the same equipment and in the same setting, but with very low resistance and no training stimulus.
The cognitive performance of the two groups was assessed using different standardized measurement methods:
- Memory performance (e.g. word list learning and delayed recall)
- Global cognitive function (ADAS-Cog)
- Executive functions and attention (e.g. trail making test, Stroop test, verbal fluency, set-shifting tasks)
In addition, MRI examinations were performed to analyze the volume of hippocampal subfields and frontal brain areas as well as grey matter. In addition, lesions in the white matter and the microstructure of the white matter were assessed using diffusion measures.
In addition, functional parameters such as maximum muscle strength, walking speed, balance and abilities relevant to everyday life were recorded.
Central results
At the end of the six-month intervention, the strength training group showed a significant improvement in global cognitive function, particularly in the areas of memory, language and orientation. Executive functions and attention also improved significantly. These effects also remained detectable 12 and 18 months after the end of training, which indicates a long-term and sustainable effect of strength training on cognitive health.
The MRI analyses showed that the intervention group exhibited either an increase in brain volume or less atrophy (shrinkage) in the hippocampus region and frontal brain areas. In addition, there was evidence of better white matter integrity, indicating more stable neuronal connections.
The strength training group also benefited significantly on a functional level: muscle strength, walking speed and everyday functions improved significantly.
In addition, a causal relationship between the increase in muscle strength and the extent of cognitive improvement was demonstrated via a dose-response relationship. This means that the greater the strength gains, the more pronounced the cognitive effects were .
Conclusion
The SMART study is one of several high-quality studies that show that strength training can effectively counteract cognitive decline in old age.
References
- Gates, N. J., Valenzuela, M., Sachdev, P. S., Singh, N. A., Baune, B. T., Brodaty, H., Suo, C., Jain, N., Wilson, G. C., Wang, Y., Baker, M. K., Williamson, D., Foroughi, N., & Fiatarone Singh, M. A. (2011). Study of Mental Activity and Regular Training (SMART) in at risk individuals: A randomized double blind, sham controlled, longitudinal trial. BMC Geriatrics, 11, 19. https://doi.org/10.1186/1471-2318-11-19
Image from shutterstock by Roberto Castillo
