The health benefits of strength training extend far beyond weight management and aesthetics.
Yep. Although most people get into exercise purely for cosmetic reasons (i.e. to build muscle, lose fat and increase their physical attractiveness), there is a substantial body of scientific evidence pointing to numerous health benefits of strength training.
But first, what is strength training?
Strength training (also known as weight training or resistance training) is a type of physical exercise which uses resistance to oppose the force generated by muscles through concentric and eccentric contractions.
While most people associate strength training with lifting weights (barbells and dumbbells), it can also be done using other equipment (e.g.: bands, suspension ropes, gym machines, etc.) or using no equipment at all (e.g. body weight exercises, such as push-ups and pull-ups).
Why doesn’t everyone lift weights?
Until recently, insufficient evidence to support the role of strength training in health promotion coupled with the belief that it should only be done by strength athletes and bodybuilders meant that the general population saw little reason to ever engage in resistance training. Thankfully, all that has now changed and people of all ages, genders, and backgrounds are hitting the gym to lift weights!
So, without further ado, here are 10 science-backed health benefits of strength training.
1. Boosts metabolic rate
One of the most well-known health benefits of strength training is that it increases the body’s metabolic rate which, in turn, can help protect from obesity and from all the health conditions that accompany it. This happens in two ways:
- Acutely for re-modelling purposes
- Chronically for ongoing tissue maintenance
Acutely, strength training causes muscle microtrauma which requires energy-intensive re-modelling.
Simply put, strength training results in tiny injuries to the muscle fibers and connective tissues of the muscles used which the body then has to “fix”. This process is called re-modelling and requires quite a bit of energy to be carried out.
In fact, according to scientific research, regularly-performed resistance training will increase Resting Metabolic Rate (RMR) by 5-10% for re-modelling purposes. With the average person’s RMR being around 1600 calories per day, that’s an additional 80-160 calories burned per day.
Chronically, properly-performed resistance exercise results in an increase in muscle mass, which requires more energy for ongoing maintenance and which, in turn, increases the body’s metabolic rate.
To put this into numbers, a 10 pound increase in muscle tissue will raise Resting Metabolic Rate by around 60 calories per day. While this increase is by no means huge, it can certainly add up over time.
2. Improves physical function
Aging coupled with physical inactivity gradually results in a reduced ability to perform basic activities of daily life, including walking around, getting out of a chair, picking up things, and reaching for things in high shelves.
According to research, the health benefits of strength training include that it can slow down and even reverse many of the negative effects of inactive aging, including:
This is achieved partly because of the positive effects that strength training has on muscle and strength as well as on body fat levels.
3. Helps prevent/manage type 2 diabetes
Physical inactivity, poor dietary habits, obesity, and age-related declines in insulin sensitivity all contribute to the development of type 2 diabetes.
The health benefits of strength training include that it can help with the prevention and management of diabetes by:
The above are supported by a number of scientific studies, including by this meta analysis by Flack et al.
4. Improves cardiovascular health
Although there are a number of risk factors which are associated with cardiovascular disease and which we have no control over (such as age, gender, and genetics) there are a few ones which we can control.
These modifiable risk factors include, but are not limited to:
- type 2 diabetes,
- resting blood pressure, and
- blood lipids.
Obesity has been linked to a number of risk factors which contribute to the development of cardiovascular disease. According to scientific research, strength training can help in the management of obesity, with studies showing that it can result in a significant decrease in fat mass. Research also suggests that strength training causes significant reductions in subcutaneous and visceral abdominal fat.
Type 2 diabetes is also a risk factor for developing cardiovascular disease. As mentioned above, resistance exercise is known to reduce the risk of developing type 2 diabetes, especially in people who are at higher risk of developing diabetes in the first place.
High resting blood pressure (hypertension) is another major risk factor for cardiovascular disease. Hypertension stresses the body’s blood vessels, causing them to become weak and clogged. Numerous studies have shown significant decreases in resting blood pressure in subjects performing regular resistance training for a few weeks. In fact, a 2005 meta analysis reported that blood pressure reductions associated with resistance training averaged around 4.5-6.0 mm Hg for systolic and diastolic blood pressure.
5. Reduces blood pressure
Hypertension (i.e. high blood pressure) is a medical condition in which the blood pressure in the arteries is persistently elevated. Left untreated, hypertension can lead to heart attacks, strokes and other health problems.
Sadly, approximately 85 million Americans (around one third of all US adults) have hypertension.
The good news?
A number of studies have found that two or more months of regular strength training can reduce both systolic and diastolic blood pressure in subjects with hypertension.
This study, for example, which included more tore than 1,600 participants aged between 21 and 80 years old, found that strength training twice or three times per week significantly reduced systolic blood pressure readings by 3.2 and 4.6 mm Hg, respectively, while it also reduced diastolic blood pressure by 1.4 and 2.2 mm Hg, respectively.
Moreover, a 2005 meta-analysis of randomized controlled trials by Cornelissen and Fagard reported reductions that averaged 6.0 mm Hg in systolic and 4.7 mm Hg diastolic blood pressure, and concluded that resistance training could become part of a non-pharmacological intervention strategy to prevent and combat hypertension.
6. Improves blood lipids
A typical blood lipid profile usually refers to the blood levels of:
- total cholesterol,
- high-density lipoprotein (HDL), i.e. the “good” cholesterol,
- low-density lipoprotein (LDL), i.e. the “bad” cholesterol, and
Undesirable blood lipid profiles, also known as dyslipidemia, usually mean that LDL and/or triglyceride levels are high and that, sometimes, HDL levels are low, and are one of the recognized risk factors for cardiovascular disease.
Although some research has found no significant changes of strength training on blood lipids, most studies, such as this one, this one, and this one, have shown that the health benefits of strength training do actually include improvements in blood lipid profiles.
According to the American College of Sports Medicine (ACSM) position stand on Exercise and Physical Activity for Older Adults, the available scientific evidence suggests that strength training may increase HDL cholesterol by 8% to 21%, decrease LDL cholesterol by 13% to 23%, and reduce triglycerides by 11% to 18%.
7. Helps manage chronic pain
Chronic pain, often defined as pain that lasts over 12 weeks, is a major public health problem. According to a 2011 report by the the Institute of Medicine (IOM), the prevalence of chronic pain in the United States has been estimated to be close to 116 million, which means that approximately half of all American adults are living with chronic pain.
The health benefits of strength training include that it can treat several types of chronic pain, including low back, osteoarthritis, and fibromyalgia pain.
Low back: A large number of randomized controlled trials and systematic reviews have found that exercise reduces pain and improves physical function in people suffering with low back pain. The efficacy of strength training alone has been examined in fewer trials, with a quantitative review by Hayden et al. revealing that strength training is as effective in reducing pain and more effective in improving physical function than aerobic training in those suffering with low back pain.
Osteoarthritis: Research suggests that exercise of all types is effective in reducing osteoarthritic pain, with quantitative reviews, such as this one by Roddy et al. and this one by Pelland et al., that looked at trials utilizing strength training alone, showing a moderate-sized, positive effect of strength training for reducing pain associated with osteoarthritis.
Fibromyalgia: Randomized controlled trials that have examined the effects of strength training alone on pain in fibromyalgia patients have found pain reductions that range from moderate (e.g., in this study) to large (e.g. in this study), with the evidence supporting the conclusion that strength training alone effectively reduces pain intensity among patients with fibromyalgia.
8. Increases bone mineral density
Bone mineral density (BMD) refers to the amount of bone mineral per unit of bone tissue, and, essentially, reflects the strength of bones. Low bone mineral density (osteoporosis or osteopenia) means that bones are weak and, therefore, more prone to fractures.
Osteoporosis affects an estimated 75 million people in Europe, USA and Japan, with more than 8.9 million fractures worldwide caused by osteoporosis.
According to research, adults who do not perform strength training may experience up to a 3% reduction in bone mineral density every year of their life.
On the positive side, a number of longitudinal studies as well as a recent review by Going and Laudermilk, have found significant increases in BMD of up to 3% with strength training%.
Moreover, although much of the research on strength training and bone mineral density has used older women as subjects, there is evidence which suggests that young men may also increase BMD by up to 7.7% through resistance training.
Overall, the majority of studies in this area suggest that the health benefits of strength training include an increase in bone mineral density in both younger and older adults, and may have a stronger effect on BMD than other types of exercise.
9. Enhances mental health
According to the U.S. Department of Health and Social Services, mental health includes people’s emotional, psychological, and social well-being. Since it significantly affects how we think, feel, and act, it’s no surprise that it’s considered to be hugely important at every stage of our lives.
Cognitive abilities: A number of scientific studies, such as this one, this one and this one, have found that strength training results in significant improvements in cognitive abilities. Moreover, a meta-analysis by Colcombe and Kramer showed that an exercise regimen involving both strength training and aerobic activity resulted in significantly greater cognitive improvement in older adults than did aerobic activity alone.
Self-esteem: Although self-esteem is relatively stable over time and less likely to be affected by exercise, positive changes of strength training on self-esteem have been reported in numerous studies, including this one in older adults, this one younger adults, this one in cancer patients, and this one in participants of cardiac rehabilitation.
Depression: A number of studies have examined the effects of strength training on depression levels as well as on symptoms of depression. Although the results have been mixed, O’Connor et al., in a review of the literature, concluded that there is sufficient evidence to support strength training as an effective intervention for helping to reduce the symptoms of depression in adults with depression.
Anxiety: Randomized controlled trials that have investigated the effects of strength training on anxiety (such as this study and this study) have found an overall small, but statistically significant, reduction in symptoms of anxiety, with moderate intensity training (50-60% of 1RM) showing the strongest positive effect. Overall, the available evidence suggests that strength training consistently reduces anxiety symptoms in healthy adults.
Taken together, the studies above on the the different components of mental health suggest that the health benefits of strength training include an improvement in mental health.
10. Reverses aging factors
Finally, some interesting research which has investigated the effects of strength training on muscle mitochondrial content and function suggests that resistance training can increase both the mitochondrial content and the oxidative capacity of muscle tissue.
Moreover, some research on older adults with a mean age of 68 years showed a reversal in mitochondrial deterioration that typically occurs with aging, with the older participants experiencing gene expression reversal which resulted in mitochondrial characteristics similar to those in moderately active young adults with a mean age of 24 years.
Overall, the available scientific evidence to date suggests that the health benefits of strength training include a reversal of aging factors in skeletal muscle.
So there you have it.
When properly performed, research suggests that the health benefits of strength training are numerous and, often, unique to this specific type of exercise.
Just remember, however, that it’s always a good idea to consult with your doctor before starting an exercise regimen, as well as to get guidance by a certified fitness professional regarding proper training programming and the correct execution of exercises.
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