Article Page
Resistance Training Improves Mental Health
Amenda Ramirez and Len Kravitz, Ph.D.

Article Reviewed:
O'Connor, P.J., Herring, M.P. and Carvalho, A. (2010). Mental health benefits of strength training in adults. American Journal of Lifestyle Medicine, 4(5), 377-396.

Strength training is increasingly promoted for its many health-related benefits including a lower risk to all causes of mortality, fewer cardiovascular events (i.e., heart attack, stroke), improved body composition, better glucose metabolism and insulin sensitivity, and lower blood pressure in persons with pre-hypertension and hypertension (Garber et al., 2011). Garber and colleagues continue that resistance training is a suitable intervention for the prevention and/or management of osteoporosis, osteoarthritis and metabolic syndrome.
Surprisingly, much less research has focused on the mental health benefits of resistance training in women and men. Recently, O'Connor, Herring, and Carvalho (2010) completed an extensive literature review on this topic. Highlights from their findings are summarized in this research column.

Does Resistance Training Have Any Effect on Anxiety?
According to O'Connor and colleagues (2010), 15% of the U.S. population reports frequent anxiety symptoms lasting 15 to 30 days a month. Anxiety is generally manifested with feelings of nervousness, fear, apprehension and worry. It is normal for all people to experience levels of anxiety with interviews, tests, new challenges or performances. However, with prolonged and heightened symptoms, anxiety is associated with poor sleep, mental distress, bodily pain, poor health and limitations to physical activity.
O'Connor, Herring and Caravalho (2010) summarize that the seven resistance training studies (that met their criterion for quality research) reviewed on this topic demonstrate that resistance training is a meaningful intervention for people suffering from anxiety. Interestingly, two of the seven studies compared the effects of high-intensity resistance training (exercises performed at 80% of 1-repetition maximum {1-RM}) versus moderate-intensity (50%-60% of 1-RM) and found that anxiety was better reduced with the moderate-intensity resistance training.

Does Resistance Training Improve Brain Cognition?
Cognition refers to the brain's processing ability to obtain knowledge through thought, experience and the senses. Cognition research attempts to determine how we transform events and experiences into stored memory, which can be recovered and used to complete mental and physical tasks. Highly associated to cognition is the term 'executive functioning.' Executive function is the 'command and control' conductor of cognitive skills. This brain control center is what manages all of the tasks in a person's life, such as writing an article, doing a research project, preparing for class and organizing a trip.

A great amount of research on exercise and cognitive function has been completed with older adults, as it is felt this population may potentially have consequential benefits to gain from the training. O'Connor, Herring, and Carvalho (2010) note that seven randomized controlled studies show that resistance training has been shown to improve several aspects of cognition in healthy older adults. Uniquely, one of the most profound effects of resistance training is the marked improvement in memory and memory-related tasks. Additionally, it appears that improved executive functioning is one of the major benefits from resistance training (Anmderson-Hanley, Nimon and Westen, 2010) as well as cardiovascular exercise (Colcombe and Framer, 2003).

Does Resistance Training Have Any Effect on Depression?
In life, most people feel sad or depressed at times due to life's challenges and as reactions to losses in life. However, intense sadness may lead to feelings of hopelessness and helplessness resulting in mood disturbances, fatigue, lack of motivation, insomnia (or excessive sleep called hypersomnia), restlessness, agitation, and body weight fluctuations. O'Connor, Herring, and Carvalho (2010) highlight that the 18 training studies examining the effect resistance training in persons with symptoms of depression has mixed results. Several studies show a significantly positive effect from the resistance exercise while others have shown little change in depression. Perhaps further investigation is needed to determine if there is an optimal dose of resistance training for persons suffering from symptoms of depression. Four studies have investigated the effect of resistance training with clinically diagnosed depressed adults. The results are unanimous; large reductions in depression from resistance training participation.

Does Resistance Training Have any Effect on Chronic Fatigue?
O'Connor and colleagues (2010) highlight that about 25% of the U.S. population experience persistent fatigue symptoms. In addition, the occurrence of chronic fatigue is elevated among people with lasting medical illnesses, especially those with psychological disorders. Fatigue is a common reason some people see their primary practitioner frequently, and an excuse some people use for not exercising. Impressively, 94% of the 70 randomized studies on exercise and fatigue show that exercise is clinically beneficial (i.e., significant) and even more beneficial than drug or cognitive-behavioral interventions (O'Connor, Herring, and Carvalho). In fact, a strength training only intervention results in the largest improvements in chronic fatigue.

Does Resistance Training Have any Effect on Self-Esteem?
Self-esteem is a person's opinion about herself/himself. It is a personality characteristic of how a person regards his/her self-worth, self-respect and self-integrity. High self-esteem is highly associated with positive physical and mental well-being. Resistance training has been shown to improve self-esteem in healthy younger and older adults as well in cancer, cardiac rehabilitation and depression patient populations.

Does Resistance Training Have any Effect on Sleep?
O'Connor, Herring, and Carvalho (2010) observe that we spend 30% of our lives sleeping, and that insufficient sleep is very problematic to our physical and mental health. Consistent sleep deprivation (< 6 hours a night) is associated with cognitive impairment, mental illness, hypertension, obesity, cardiovascular disease, stroke, daytime sleepiness, motor vehicles accidents and a diminished quality of life (O'Connor, Herring and Carvalho). O'Connor and colleagues continue that the research indicates that physically active people usually have healthy sleep patterns and a lower risk to sleep apnea. Furthermore, the research shows that depressed persons with sleep disorders show a 30% improvement in sleep from a regular resistance training intervention. These results appear to become most effective after 8-10 weeks of consistent resistance training.

How Does Resistance Training Improve Mental Health?
The mechanisms how resistance training improves mental health are quit speculative at this time. O'Connor, Herring and Carvalho (2010) propose that there is a complex network of neurophysiological adaptations that occur with resistance training participation that directly and indirectly effect mental processes. For instance, many of the physical health benefits of resistance training cited in the first sentence of the article can have a direct and indirect effect on a person's mental well-being. In addition, resistance training may improve the body's central nervous system functioning which could positively effect on a person's mental health (O'Connor, Herring, and Caravalho). van Praag (2009) expounds that improved cognition from exercise is likely to be multi-factorial adaptations involving new nerve cell generation in the brain, an increase in neurotransmitters (chemical substances that transmits nerve impulses across a synapse, and new brain blood vessels for more efficient oxygen delivery and waste product removal.

Final Thoughts
The evidence is quite impressive how resistance training can improve several major mental health issues. In addition, the research is convincing that resistance training can appreciably improve cognitive function. An exercise professional's bottom line message to clients is clear. For a mental lift, you should weight lift!

Mental Health Benefits from Resistance Training
Improved memory
Improved executive control
May lessen depression
Much less chronic fatigue
Improved quality of sleep
Improved cognition
Less anxiety
Improved self-esteem

Additional References
Anderson-Hanley, C., Nimon, J.P., and Westen, S.C. (2010). Cognitive health benefits of strengthening exercise for community-dwelling older adults. Journal of Clinical and Experimental Neuropsychology, 32(9), 996-1001.
Colcombe, S. and Framer, A.F. (2003). Fitness effects on the cognitive function of older adults: A meta-analytic study. Psychological Science, 14(2), 125-130.
Garber, C.E., et al. 2011. Quantity and quality of exercise for developing and maintaining cardiorespiratory, musculoskeletal, and neuromotor fitness in apparently healthy adults: Guidance for prescribing exercise. Medicine & Science in Sports & Exercise, 43(7), 1334-1349.
van Prag, H. (2009). Exercise and the brain: something to chew on. Trends in Neuroscience, 32(5), 283-290.

Amenda Ramirez has a bachelor's degree in exercise science from the University of New Mexico (Albuquerque). She is a McNair honors student recipient whose many health-related interests include physical rehabilitation, developmental disabilities and pediatric care.
Bio:Len Kravitz, PhD, is the program coordinator of exercise science and a researcher at the University of New Mexico, where he won the Outstanding Teacher of the Year award. He has received the prestigious Can-Fit-Pro Lifetime Achievement Award and was chosen as the American Council on Exercise 2006 Fitness Educator of the Year.