Aerobic exercise increases brain blood flow and has demonstrated beneficial effects on cognition.
The effects of weight training exercise on the brain is less frequently studied. Hence, we know little about the effect and mechanism of weight training on brain function and performance.
A recent study provides some needed insight on this topic.
A study by C Suo and colleagues from Australia examined the effects of resistance training and cognitive skills training on brain structure and function.
The key elements of design in their study included the following features:- Subjects: 100 elderly subjects of average age 70 years with mild cognitive impairment
- Intervention: 6 months of progressive resistance training (PRT), computerized cognitive training (CCT), both interventions or neither intervention (sham control group)
- Cognitive assessments: MMSE, Clinical Dementia Rating Scale and a battery of neuropsychological tests
- Imaging: Pre- and post- 3T MRI voxel-based quantitative assessments of brain regions and resting state fMRI
- Statistical Analysis: SPSS linear mixed model studying three main effects, time, PRT and CCT
The findings in this study were quite remarkable:- PRT: Increased performance on global cognition
- PRT: Increased brain gray matter volume in the posterior cingulate cortex (see image)
- PRT: Increase in cigulate gray matter volume correlated with improvement in global cognition
- PRT: Reversed progression of brain white matter intensities, a biomarker of cerebrovasular disease
- CCT: Slowed progression of decline in overall memory performance
- CCT: Enhanced connectivity between brain hippocampus and superior frontal cortex
This is one of the first studies finding a significant improvement in cognitive function in elderly subjects after progressive resistance training.
Additionally, the study supports PRT's potential benefit in reversing brain white matter intensities (WMI). I have previously written a blog post on the association of WMI with increased rates of dementia and premature death. You can find that post HERE.
The take home message here is that both PRT and CCT appear to have beneficial effects on slowing the effects of aging on the brain. They each appear to have unique mechanisms and brain targets. A smart preventative program for brain health in the elderly would combine the two interventions.Readers with more interest in this study can access the free full-text manuscript by clicking on the link in the citation below.
Image showing cingulate cortex is an iPad screen shot from the app 3D Brain
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Suo C, Singh MF, Gates N, Wen W, Sachdev P, Brodaty H, Saigal N, Wilson GC, Meiklejohn J, Singh N, Baune BT, Baker M, Foroughi N, Wang Y, Mavros Y, Lampit A, Leung I, & Valenzuela MJ (2016). Therapeutically relevant structural and functional mechanisms triggered by physical and cognitive exercise. Molecular psychiatry, 21 (11) PMID: 27090304
The research support for regular exercise to be associated with reduced risk of death is growing. However, there is limited research that focuses on effects of aerobic versus strengthen (resistance) training. Additionally, there is limited data comparing mortality in those with and without a general medical condition.
Schoenborn and Stommel recently published a study addressing these issues in teh American Journal of Preventive Medicine. They examined a large sample of U.S. adults and assessed whether they met the 2008 USDHHS Activity Guidelines for Americans:- 150 minutes per week of moderate intensity aerobic activity
- OR 75 minutes per week of high intensity aerobic activity
- Encourage two days per week of weight training of 7 large muscle groups
The study examined exercise levels and mortality by linking data from the 1997-2004 National Health Interview Survey and death registry data from 1997-2006. Mortality examined in groups with no chronic medical conditions compared to those with one or more medical conditions including: diabetes, hypertension, vascular problems, lung disease (asthma/bronchitis), one or more functional limitations (any difficulty walking, climbing steps, standing, sitting, stooping, reaching, grasping, or lifting/pulling or pushing large objects).
This study was informative because it looked at the effect of aerobic versus strength versus both aerobic and strength on mortality. Additionally, it examined the effect of exercise on mortality in four age categories: 18 and younger, 18 to 44 years of age, 45 to 64 years of age and 65 and older age groups.
>The key findings from the study were:- Strength training alone was not associated with decrease mortality risk
- Aerobic exercise was linked to reduced mortality risk aerobic exercise with over 150 minutes per week somewhat better than less than 150 minutes per week ( although going above 300 minutes per week did not correlate with additional mortality reduction)
- Among those meeting aerobic exercise guidelines, adding strengthening showed a trend for correlation with an additional beneficial mortality effect
- Older adults with one or more chronic conditions appeared to have the strongest association between exercise and lower mortality risk
The chart below summarizes the magnitude of association between exercise levels and lower mortality rates in those in the 45 to 64 age category and those aged 65 and older with one or more medical conditions. To aid in interpretation of the numbers the SMR for those 65 and older with one medical condition meeting both aerobic and strengthening exercise guidelines was .52. This means during follow up they were 48% (1-SMR) less likely to die than those not meeting exercise guidelines for either aerobic or strengthening types.
Figure by author adapted from data provided in manuscript.Schoenborn, C., & Stommel, M. (2011). Adherence to the 2008 Adult Physical Activity Guidelines and Mortality Risk American Journal of Preventive Medicine, 40 (5), 514-521 DOI: 10.1016/j.amepre.2010.12.029
