A Case for Resistance Training: How straining a little (or a lot!) is good for your health. (Part 1)
Word Count: ~7350 words
Unique References: 93
Download the ebook here: link
“No man has the right to be an amateur in the matter of physical training. It is a shame for a man to grow old without seeing the beauty and strength of which his body is capable.”
- Socrates
Often when people hear the term “Resistance Training” (RT) they envision herculean men slinging hundreds of pounds with ease, bulging muscles, grunting, or the use of far too many Arnold quotes. It is often seen as exclusive to high-level athletes and only used for improving sports performance. Some people don’t consider RT to be a necessary component to a healthy lifestyle, or more specifically, they do not understand just how important it is for their health.
As someone in the health and fitness field, I feel compelled to arm people with the tools and knowledge to be self-sufficient and take their health into their own hands. Unfortunately, a lack of quality and evidence-based information (or worse, misinformation) around how to live a healthy lifestyle causes individuals to either do the wrong things or do nothing at all. In the real world, this has created a situation where people don’t know much about RT, its health benefits, or how to implement it. This article was created to address this lack of knowledge, and to provide the reader (lucky you!) with the evidence and facts about why RT is necessary, and not optional, if living your best possible life is important to you.
This article will be part of a series. Part 1, the current piece you are reading, is a comprehensive, though not exhaustive, overview of the scientific evidence on RT and health. This is where I will make the case for why any individual, and I mean ANY individual, needs to be RT in some capacity. Once I have convinced you (successfully I hope) of why you need to RT, Part 2 will address how to RT. This will include how does one actually get stronger, and what goes into a program.
Sound like a plan? Let us begin!
Lay of the Land - How healthy are we?
Since the advent of modern medicine, vaccines, clean water and the practice of proper hygiene, western society worries little of the diseases rampant 50 to 100 years ago. However, with the increased availability of cheap, calorie-dense, and convenient foods coupled with a sedentary lifestyle, a new scourge of illnesses are affecting our society. These “Diseases of Inactivity”, which include cardiometabolic complications like type 2 diabetes, obesity, and cardiovascular disease, drastically decrease quality of life and significantly increases the risk of premature death. This is why Physical Inactivity is the 4th leading risk factor for global mortality, responsible for 6% of all deaths in the world and is estimated as being the principal cause for approximately 21–25% of breast and colon cancer burden, 27% of type 2 diabetes development and approximately 30% of ischaemic heart disease cases (link).
To put this into context, 1 out of every 16 people you know will die due to not being physically active enough throughout their lifetime (or more precisely, from the diseases that crop up from being inactive). This problem will only get worse, as globally over 80% of kids aged 11-17 years of age are insufficiently active (link). Research examining the positive health effects of exercise is well established, including its potent benefits on various chronic illnesses, both in terms of prevention and treatment. This then begs the question, how much activity is needed to prevent diseases and improve our health?
How much should you be training?
The most recent Physical Activity recommendations set out by the American College of Sports Medicine (ACSM Complete Guide to Fitness & Health, 2017) include recommendations for both Aerobic exercise and RT. The minimum weekly amounts required to elicit a wide array of health benefits are:
150 minutes of Moderate Aerobic Activity OR 75 minutes of Vigorous Aerobic Activity
AND; 2-3 days per week of RT (Note - the Canadian guidelines include strengthening activities in the 150 minutes)
Notes:
Moderate aerobic activity is anything that noticeably increases heart rate and breathing like brisk walking (so not very strenuous!)
Vigorous aerobic activity is anything that substantially increases heart rate and breathing like jogging or running
RT includes any form of exercise, performed over time, that increases someone’s ability to produce muscular force in a particular context.
These numbers are not to suggest there is no benefit with lower levels of activity. There will still be health benefits, just perhaps not as significant. Anything is better than being sedentary!
Keep in mind, these are minimums to get some health benefits, these are not maximums. More activity will result in more benefit, which is known as a Dose-Dependent Relationship.
Now that we know how much we should be getting, how much activity are people actually getting? Around 52% of Americans achieve the physical activity guidelines for aerobic exercise, but only about 22% achieve both the aerobic and RT guidelines (CDC, 2017). Canadians fair worse, with only 16% of adults between 18-79 years of age achieving the minimum threshold of 150 minutes of activity per week (link). As we can see from these startling figures, a significant portion of the population is not active enough to promote good health or to prevent many of the common illnesses our society is dealing with.
Why are we so inactive?
It is beyond the scope of this article to extensively examine the barriers to exercise participation, but a synopsis includes; a lack of time (or perceived lack of time in many cases), social influences (your friends don’t exercise), lack of energy (perhaps from dietary factors), lack of motivation, fear of injury, lack of skill to perform exercise, lack of resources, distance of travel to facilities and other obligations. However, one major barrier, which this article is hoping to address is a lack of education, or misinformation, regarding the benefits of physical activity, specifically around RT.
Most people know exercise is good for them (I hope…), but when pressed, people tend to know very little about how much exercise they actually need, what effect aerobic exercise and RT actually have on the body, the sheer number of health complications that can stem from being sedentary, and how being physically active can actually prevent and improve most chronic health issues. The remainder of this article is to address the questions……(1) What are the health benefits of RT, and (2) Why everyone needs to do it!
But first...
To put RT into context, and why it must have its own unique place in a general fitness program, it would be useful to differentiate what aerobic, or cardiovascular, exercise actually is as well. Aerobic exercise, which focuses on any submaximal activity that uses large amounts of oxygen (like walking or jogging), primarily targets cardiorespiratory function. This includes your heart, lungs and blood vessels, as these are the structures that receive and distribute the oxygen we breathe to the cells of the body that needs it. So when you become more aerobically fit, your heart gets better at pumping more blood, you uptake more oxygen and use it more efficiently, and your resting blood pressure and heart rate decrease. Being aerobically fit allows you to recover from exercise much more quickly, helps with maintaining a proper body weight, and reduces the likelihood of many chronic health conditions (heart disease etc). Doing aerobic exercise is fantastic, however, if an individual only engages in aerobically based activities, many facets of health could be left undertrained.
Strength Training...what’s all the fuss?
A resistance exercise, in its most basic sense, is any movement that causes the muscles to contract against an external force or ‘resistance’ with the intention of increasing muscle strength, size and/or function. Resistance Training, however, is an intelligently designed plan to achieve those goals in a consistent and systematic fashion over long periods of time. That’s why professionals in my field often make the point that exercising and training are two different things (hint - most people don’t actually train, they simply exercise randomly, which is why they don’t see consistent results). Unfortunately people often only consider the effect RT has on muscles, particularly increased muscle size and strength. However, properly implemented RT has beneficial effects for our connective tissues, bones, nervous system, and surprisingly, injury risk.
Connective Tissues
All tissues in the human body will adapt and remodel to cope with whatever stressors are applied to them (i.e., like those experienced during consistent training). Conversely, if inadequate amounts of stress are applied (i.e., being sedentary), then the tissues will degrade and become less robust (“Use it or lose it”). Connective tissues, like tendons and ligaments, are no different. Tendons, for example, attach muscle to bone, so as you contract a muscle it will pull on your bones via its tendon. This stress (i.e., the stretch applied by the muscle to the tendon) is what the tendon will adapt to by laying down more collagen fibers and connecting them more tightly, resulting in stronger and more robust tendons (Legerlotz, 2016). The more pull on the tendon, as what happens when you lift heavy weights, a higher degree of adaptation will occur (so long as there is sufficient recovery). Resistance training can also reduce much of the connective tissue dysfunction/degradation associated with aging (Guzzoni, 2018). As long as regular stress beyond resting levels is applied periodically (like in a proper RT program), these tissues will remain strong and less prone to soft tissue injuries like sprains.
Bone Mineral Density (BMD)
Strong bones are particularly important for aging individuals to help prevent fractures and retain their independence. This is assessed by monitoring ones BMD, which is a measure of the mineral content in your bones. The more mineral content there is, more specifically calcium and phosphorus, the stronger your bones. Many things can affect this content level, like genetics, various diseases, your environment, and lifestyle factors like smoking, diet and activity levels. Bones, like tendons, will only adapt when stress is applied to them and physical inactivity is associated with worse BMD levels (Chilibeck, 1995). Bones respond particularly well to high mechanical strains caused by pulling muscles or gravitational forces, and is site-specific, meaning where the stress is applied is where the bone will get stronger (Morel, 2001). This is why powerlifters have better lumbar and whole-body BMD than normal people (Tsuzuku, 1998). Change of direction sports like squash (or those with lots of high-speed accelerations and decelerations) tend to increase BMD more than other sports like dance, swimming or distance running (Heinonen, 1995; Scofield, 2012; Gomez-Bruton, 2018), which may be why endurance athletes tend to have a higher prevalence of stress fractures compared to athletes of other sports (Rizzone, 2017).
To illustrate how RT can improve BMD, let’s take a look at the barbell back squat. The muscles of the thighs and trunk must contract to perform the squat, which pull on the bones of the leg, pelvis, and spine. This mechanical stress causes those areas to adapt resulting in the bones becoming more dense over time. Similarly, the load from the bar across the back of the shoulders will cause forces to go down through the trunk causing further BMD improvements in the spine. This is why structural exercises like the squat and deadlift are often recommended to increase the strength of bones, especially in post-menopausal women. Research has found individuals who do not regularly strength train may experience a 1% to 3% reduction in BMD every year, but thankfully many studies have found BMD can improve in 4-24 months after commencing a RT program (Westcott, 2012). A deeper dive into RT and BMD disorders, like Osteoporosis, will be covered later in this article.
Coordination
Coordination essentially means how smoothly and efficiently we can use different parts of our body during a movement task, and can either be intra-muscular (coordination of a single muscle) or inter-muscular (multiple muscles coordinating together). Intra-muscular adaptations from RT result in a single muscle becoming more efficient, so things like increased motor unit recruitment and synchronization (higher force outputs), as well as firing frequency (speed of contraction) all improve. Inter-muscular adaptations relate to how well different muscles work together during a movement (i.e., smoothness), and it often gets better with practice and/or training. This is why an individual’s strength levels are heavily influenced by the efficiency of their nervous system.
This is easily seen with a newborn learning how to walk. Initially it is very wobbly and “uncoordinated”, but over time as the coordination between muscles improves, the walking starts to look smoother and more efficient. This is due to improvements in how opposing muscle groups work together as well as improved activation from stabilizing muscles, which combine to create the most effective movement solutions for the task(s) at hand (in this case, better walking skills). RT has been shown to improve intra- and inter-muscular coordination (Cormie, 2011; Folland & Williams, 2007). For example, in a barbell bench press, the intra-muscular coordination of the chest muscles improves to produce more force at a faster rate, while the inter-muscular coordination between the chest, shoulder and tricep muscles work together to produce a more efficient bench pressing movement. If you continue to practice the bench press, over time, these adaptations will continue to improve and will result in a stronger bench press.
Injury Risk Reduction
One of the lesser known benefits of RT is its well established association with reducing injury rates. A large systematic review found that “increasing strength training volume and intensity [was] associated with sports injury risk reduction” (Lauersen, 2018). A popular saying amongst the strength training community is “Stronger people are harder to kill”, so there seems to be some truth to this. Though a person’s actual risk for obtaining an injury is multifaceted, and we can’t actually predict when an injury will occur, some common risk factors for obtaining an injury include muscular imbalances, muscle weakness, fatigue, coordination deficits, poor biomechanics, low degree of tissue resilience, previous training history, and overall fitness levels. Getting stronger over time can help to improve many of these risk factors, and there is a dose-response relationship, meaning the stronger you get, the more protected against injuries you become.
The mechanisms by which getting stronger can help reduce the likelihood of an injury can be either direct or indirect. The direct mechanisms include better muscular balance, increased joint stability, tougher tissues (i.e., tendons), better ability to handle high loads through your body, and more fatigue resistant muscles. These direct adaptations happen in the areas actually being targeted with training. For example, injury prevention programs that include specific hamstring strengthening exercises have been shown to decrease hamstring injury rates by 50% in soccer players (Al Attar, 2017). Indirect mechanisms are more global, and include a better psychological perception of being able to do a task, better coordination, higher overall fitness levels and preparedness to do various activities. There is also a growing body of research showing athletes who have higher chronic training loads, meaning they have higher fitness levels, are less prone to sports injuries as they are better equipped to handle sudden spikes in training volume (Gabbett, 2016). So the more well-trained you become, the less susceptible you are to hurt yourself, as long as you keep this fitness base over the long term (aka “Use it or Lose it”).
As an example, from everyday life, imagine you are spending an afternoon rearranging your basement, and there are a lot of heavy and awkward boxes to move. Every time you bend over and pick up a box you are using muscular strength in your arms, back and legs. If you are weaker and less trained you might only be able to do this 15 times before those muscles become fatigued, at which point you start changing how you lift, which can put more strain on certain tissues, putting you at an increased risk for straining a muscle. However, if you are much stronger, you could maybe lift boxes 100 times before you fatigue to the point of getting hurt. Often when people hurt their backs doing seemingly everyday activities, it's because they are not prepared to perform those tasks at that time (i.e., undertrained and weak), not that the actual task is inherently dangerous.
Resistance Training and Health…
“If you don’t take time for your wellness, you will be forced to take time for your illness”
The discussion that follows will explore the effect RT has on many common chronic health issues, previously referred to as the “Diseases of Inactivity”. This is not an attempt to discourage other forms of physical activity, or downplay to role proper diet has in health, but to show that RT plays an invaluable role in maintaining good health, and is highly efficacious for improving outcomes in illnesses where it is typically avoided or seldom used.
Obesity (Visceral or Abdominal Fat)
It is estimated that roughly 34% of Canadians are overweight (BMI >25) and 27% are obese (BMI > 30)(link). Body Mass Index (BMI) isn’t terribly useful on its own when evaluating a single person, but when combined with that person’s Waist Circumference (WC), which is a measure of Visceral Fat (VF), it can be more predictive of negative health outcomes. An elevated WC of ≥40 inches (102 cm) for men and ≥35 inches (88 cm) for women is associated with many poor health outcomes (link). VF is a more dangerous form of body fat (hence “Heart Attack belly”) as it releases hormones called “adipokines” which causes systemic inflammation throughout the body and is thought to be the main driver for the poor health outcomes associated with obesity (Fontana, 2007). Having a high BMI combined with a high WC is indicative of increased cardiometabolic risk (Sullivan, 2019), and significantly increases your risk for developing things like Type 2 Diabetes, heart disease, sleep apnea, osteoarthritis, cancer, poor wound healing, and more (Billington, 2000; Abu-Abid, 2002; Rosales, 2014).
Therefore, the key in obesity management is reducing body fat levels, and especially reducing WC, as this will have a positive impact on reducing systemic inflammation and improving other health complications. Calorie restricted diets are obviously effective at decreasing body weight, however, dietary restriction combined with exercise appears to produce up to 20% greater weight loss initially, with better maintenance of long term weight loss, than dietary restriction alone (Sullivan, 2019). Interestingly, restricted dieting have been shown to decrease resting metabolic rate up to 30% due to decreases in muscle mass (Tresierras, 2009), therefore it has been recommended that RT is included in weight loss programs to maintain and increase muscle mass, resulting in longer lasting results. Even though aerobic training combined with RT generally yields the best results for weight loss, in the case of heavier individuals, RT may be a more feasible training option (e.g., machines and exercise modifications) helping to increase enjoyment and compliance to a training program.
Cardiovascular Disease (CVD) & Hypertension
Hypertension, or High Blood Pressure, is one of the strongest risk factors for developing many types of cardiovascular diseases (e.g., heart attack or stroke), increasing your risk by 3 times compared to someone without hypertension (Kannel, 1993). It affects 1 in 4 Canadian adults (link). Aerobic exercise is typically thought to be more important for heart health than RT, and while it is definitely an important preventative tool, RT can still play a major role in maintaining a healthy heart.
During RT, like any form of physical activity, your muscles contract which requires a constant supply of oxygenated blood to supply the muscles with nutrients and remove waste products. This increased demand for blood increases your heart rate and causes your cardiovascular system to become more efficient. If training volumes are high enough, and you resistance train regularly, you will gain many important aerobic adaptations like a lower resting heart rate, decreased resting blood pressure, and stretchier arteries (Sullivan, 2019; Braith & Stewart, 2006). This is why RT in combination with aerobic training has shown the best improvements in cardiovascular health, and is recommended in heart disease rehabilitation protocols, over aerobic exercise alone (Xanthos, 2017).
Besides directly affecting the aerobic system, a potentially more important reason to include RT is due to the increase and maintenance of muscle tissue. Muscle is a metabolically active tissue, meaning it requires calories and secretes hormones, so any reductions in muscle mass due to either aging or physical inactivity can increase the prevalence of several health issues like obesity, insulin resistance, type 2 diabetes, dyslipidemia, and hypertension. The development of these health issues can have a direct effect on cardiac structure, arterial stiffness and endothelial function, which can increase the risk of CVD and other heart related conditions. RT increases muscle mass and can help reduce many CVD risk factors (Braith & Stewart, 2006).
Type 2 Diabetes & Insulin Resistance
RT and being physically active is incredibly important in the prevention and management of Type 2 diabetes. Skeletal muscle is the primary metabolic “sink” for glucose, meaning that muscle uses glucose both at rest and during activity (i.e., muscle contraction). The more metabolic demand imposed on the muscle (i.e., during and after bouts of exercise), the more glucose is needed for energy and the faster it is used. This is why RT and other forms of activity have been shown to help improve glycemic control and insulin sensitivity (Braith & Stewart, 2006; Conn, 2014), and why low muscle mass is a risk factor for developing type 2 diabetes (Son, 2017).
RT is also important for preventing Type 2 diabetes, as one study which followed 32,000 men for 18 years found those engaging in RT for >150min per week had a 34% reduction in their risk for developing Type 2 diabetes (Grontved, 2012), even after correcting for aerobic activity and BMI. The same study also found that for every hour of RT done each week resulted in a 13% reduction in risk, so the more you do the more protection you get. This is in part due to the effect that RT, and exercise in general, can have on helping to prevent many risk factors that promote Type 2 diabetes, like obesity, abdominal fat, insulin resistance, and being inactive (Wu, 2014). Therefore, the more muscle mass someone has (especially as they age) and the more they use their muscles, the less risk they have for developing diabetes and other metabolic disorders.
Hyperlipidemia
Hyperlipidemia simply means you have high amounts of fat in your blood, such as cholesterol or triglycerides. This is problematic because chronically elevated cholesterol levels are strongly related to developing coronary heart disease (Lloyd-Jones, 2004). It has also been reported that individuals with elevated total cholesterol levels (>200 mg/dL US or >5.2 mmol/L Canada) have approximately twice the CHD risk of those with optimal levels (Roger, 2012), which is the case for nearly 50% of Canadians over 18 years of age (link). Thus, interventions that help to control and lower blood lipid profiles are of high priority, because we know that reductions of the bad type of cholesterol, or LDL, helps to decrease the incidence of heart attacks and ischaemic strokes (Baigent, 2010).
According to the American College of Sports Medicine position stand on Exercise and Physical Activity for Older Adults (2009), RT may increase HDL cholesterol (the good kind) by 8% to 21%, decrease LDL cholesterol (the bad kind) by 13% to 23%, and reduce blood triglycerides by 11% to 18%. RT can improve blood lipid profiles, but it seems higher volumes (like in a circuit fashion) rather than higher intensities, illicit the greatest effects (Mann, 2013), as this helps to increase lipid oxidation (aka how much fat you burn for energy).
Sarcopenia & Cachexia
Sarcopenia, also known as “poverty of flesh,” is the unintentional loss of muscle mass and strength associated with aging (Lenk, 2010), with estimates suggesting between 10-40% of adults over 60 years old are suffering from this condition (Mayhew, 2019). Many factors affect how quickly this occurs (i.e., sedentary behaviors), but estimates suggest up to 8% of muscle mass is lost every decade after 30 years of age, with this rate getting even higher after age 60 (Volpi, 2004). This decline in muscle mass is slower in people who have remained physically active (especially with RT) throughout their life. Cachexia, on the other hand, is the unintentional loss of muscle associated with an underlying illness like cancer, rheumatoid arthritis, COPD or heart disease. Compounded by factors like the inability to eat from chemotherapy, Cachexia causes many of the same sarcopenic complications, on top of the initial illness. This further complicates healing from the original ailment.
This progressive loss of muscle mass is a physical, functional, and metabolic catastrophe. The loss of muscle mass and strength directly increases physical inactivity, joint stiffness, body fat percentage, kyphosis (i.e., rounded back), frailty and the risk of falls, while also decreasing bone mineral density. Losing metabolically active tissue like muscle is why sarcopenia is associated with decreased insulin sensitivity, and an increased risk for developing illnesses like osteoporosis, obesity, type 2 diabetes, cardiovascular disease and stroke (Sullivan, 2019). Any loss of muscle mass will decrease quality of life, and increase the risk of many serious health concerns.
Type 2 muscle fibers (i.e., Fast Twitch), which are larger and more powerful than Type 1 (i.e., Slow Twitch), seem to be the most affected by Sacropenia (Nilwik, 2013) yet just so happen to be the fibers most improved through RT. This is why the results of multiple observational studies suggest that aging adults can slow down, stop, or reverse the degenerative effects of sarcopenia with RT (Frontera, 1988; Nilwik, 2013]. RT (and endurance training) is therefore recommended as a powerful, non-pharmacological, treatment for maintaining muscle mass, strength and function for both sarcopenia and cachexia (Lenk, 2010).
Osteoporosis & Osteopenia
Osteoporosis, and its precursor Osteopenia, is the gradual weakening of bone, affecting over 1.4 million Canadians, primarily women and older adults (link). Approximately 23% of Canadian adults >50 years old will experience an osteoporotic related fracture in their lifetime (Ballane, 2017). There are many ‘modifiable’ risk factors (meaning we can change them and therefore decrease risk) associated with developing osteoporosis, such as low body weight, smoking, high alcohol consumption, poor diet, but specifically to our discussion in this article, physical inactivity, low muscle mass, and muscular weakness. Often thought as an unavoidable reality of aging, in actuality, studies have shown that bone mineral density in postmenopausal women can be maintained or increased through exercise (Preisinger, 1995; Hartard, 1996; Kemmler, 2004; for more info on bone health please see - link).
As discussed earlier, bones need stress to become stronger, either through external loads or from muscles pulling on tendons. RT is a particularly useful tool in treating osteoporosis by increasing BMD and improving strength and balance (less likely to fall), however, the key is that the intensity used is high enough to stimulate adaptation. One study found a group of postmenopausal women with very low bone mass who performed a high-intensity RT program for over 8 months had superior increases in bone mass and physical function compared to a group of similar women who did a typical home-based low-intensity program (Watson, 2018). To quote one review, “High-intensity resistance training, in contrast to traditional pharmacological and nutritional approaches for improving bone health in older adults, has the added benefit of influencing multiple risk factors for osteoporosis including improved strength and balance and increased muscle mass” (Layne & Nelson, 1999). So besides being a very safe means of directly improving BMD, RT helps to prevent osteoporosis from happening in the first place, rather than simply reversing it.
Osteo & Rheumatoid Arthritis
Osteoarthritis (OA) is one of the most common musculoskeletal disorders causing pain and cartilage degradation of the joints. It affects more than 10% of Canadians over the age of 15 (link), yet it becomes more prevalent the older someone gets. Commonly thought to be from age-related ‘wear and tear’, muscle weakness can actually be a risk factor for developing OA (Øiestad, 2015). Also, emerging evidence suggests that pro-inflammatory hormones from excess fat tissue may be a significant risk factor (Pereira, 2015), highlighting the fact that being weak and overweight is likely more responsible for OA pain than simply ‘wear and tear’.
Rheumatoid Arthritis (RA), on the other hand, is an auto-immune disease attacking the joints, affecting close to 300,000 Canadians (link). Both types of arthritis cause significant pain and functional disability, leading to depression, decreased self-efficacy and a reduction in physical activity resulting in further losses of muscle mass, strength, and independence. This lack of activity, in part due to the understandable fear of further aggravating their symptoms, can lead to increases in other secondary health issues (e.g., decreased bone density, increased risk of cardiovascular disease, etc).
RT is important in managing both OA and RA due to the increases in muscle strength and size, better joint stability, improvements in overall functional capacity, and decreases in fat mass (i.e., pro-inflammatory markers) while helping to address other disease complications, such as osteoporosis, dyslipidemia, and insulin resistance. Individuals with arthritic pain often present with muscle weakness around the affected joints potentially leading to more pain, which is why patients participating in RT interventions achieve significant reductions in pain symptoms and disability (Lange, 2008). In particular, higher intensity RT programs tend to show greater improvements in strength, functional status, and decreases in pain, compared to low intensity training, and is well tolerated in both OA and RA (Vincent, 2012; Baillet, 2012; Tanaka, 2013; Sullivan, 2019). The takeaway is that RT can help improve strength and joint stability in those with OA and RA to better support painful joints and slow disease progression, leading to better management of pain symptoms while improving secondary health outcomes.
Cancer
With a 1 in 5 chance of dying from any form of cancer (link), finding ways to decrease the risk of developing cancer in the first place is a major health priority for all adults. Especially when you consider roughly 25% of all cancer cases worldwide are due to preventable factors like excess weight and physical inactivity (McTiernan, 2008). Being physically active is associated with a reduced risk of developing several types of cancer (Rezende, 2018), for example, it can help reduce the risk of developing colon cancer by 24% (Wolin, 2009). This is why the American physical activity guidelines actually suggest doubling the physical activity guidelines (i.e., from 150 to 300 minutes of moderate aerobic activity per week) to get more of a protective effect from cancer. RT can be a great way to get these benefits.
RT is also particularly useful for cancer patients and survivors, due to the high levels of fatigue and resultant Cachexia (i.e., muscle wasting related to illness) which affects 50-80% of cancer patients (Lira, 2014). This is why those suffering from cancer present with significant losses of strength, muscle function and a host of other complications that make recovery much more difficult. RT is well tolerated by cancer survivors and can help by increasing muscle mass, BMD, functional ability, reduce fatigue and improved quality of life (Strasser, 2013), as long as it is implemented based on the individual’s current abilities.
Pre- and Post-Operation
Since RT improves muscle function, connective tissue strength, and coordination, it is particularly useful for recovery after surgery. Research shows that RT prior to surgery can help improve post-op pain, functional outcomes and reduce hospital stays. One such study found that “High-intensity strength training during the preoperative period reduces pain and improves lower limb muscle strength, range of motion (ROM) and functional task performance before surgery, resulting in a reduced length of stay at the hospital and a faster physical and functional recovery after [a Total Knee Replacement]” (Calatayud, 2017).
RT is especially useful in the rehabilitation period post-surgery as one study found that after hip replacement surgery, the group that performed RT spent nearly 40% less time in the hospital (10 days vs. 16 days), while improving muscle mass and strength significantly more than the group that did ‘standard’ rehabilitation (Suetta, 2004). The interesting thing was that the standard rehab was 1 hour every single day, while that RT group was only 3 days per week, so an added benefit was that much less training time was needed to get more of a benefit. Another study found that individuals who did low back strengthening 1-2x per week for 12 weeks after undergoing back surgery had better improvements in strength, less disability and less low back and leg pain, compared to those that did not strength train at all (Kim, 2010).
Chronic Pain
Chronic pain is the persistence of pain symptoms lasting beyond the body’s natural healing process, usually longer than 3 months, affecting around 19% of Canadians (Schopflocher, 2011). This prolonged suffering can lead to other issues like fatigue, depression, poor sleep, issues working, anxiety and decreased quality of life. A highly complex issue, there is evidence to suggest that psychological and social factors can significantly contribute to the severity and persistence of chronic pain (Sullivan, 2019). For example, catastrophizing (i.e., irrationally negative thoughts towards pain) and kinesiophobia (i.e., fear of movement) can increase the risk of future low back pain (Picavet, 2002), and can cause more intense pain experiences (Vaegter, 2018). As well, low self-efficacy (i.e., control over own situation) around chronic pain is related to more intense pain perceptions (Lin, 1998).
RT has been shown to help decrease the severity of chronic pain while improving physical function and quality of life (Gennen, 2017; Busch, 2013). Being more physically active also improves general health and decreases the progression of diseases from sedentary behaviors (like those previously discussed) that is common in people with chronic pain who avoid movements they perceive as harmful to their condition. RT can help to modulate the psychosocial factors associated with persistent pain, as it can help develop self-efficacy, decrease fear of moving and help improve anxiety and depression, which as said previously, are more associated with chronic pain than a specific biological issue.
Note - the above health issues are only a small sample of the conditions that improve with consistent RT. There are many different conditions I did not include like cirrhosis, COPD, kidney disorders, stroke prevention (and rehabilitation), chronic fatigue and Parkinson’s. All of these illnesses have ample evidence that RT can be used to improve symptoms and promote physical activity and overall health. The larger point being, RT (and other forms of physical activity) have profound and wide-ranging health benefits, and the costs of not partaking in it regularly can have serious health consequences.
That one weird trick to live longer!
One of the most interesting areas of RT research is the effect it has on mortality. More specifically, there is strong evidence that people with low muscular strength and muscle mass die sooner to all causes than their stronger counterparts (Sullivan, 2019; Li, 2018; Volaklis, 2015; FitzGerald 2004). These ‘causes’ can be many, including cancer, cardiovascular disease, and other chronic diseases. For example, a study of over 1.1 million Swedish men followed over 24 years found that the strongest individuals had a 20-35% reduction in premature death due to any cause, regardless of what their BMI or blood pressure was (Ortega, 2012).
The mechanism through which higher muscular strength may be protective against dying sooner is because it combats many of the chronic health issues we discussed above. RT improves muscle function/size, increases insulin sensitivity, reduces blood pressure, makes bones stronger and reduces the risk of falls (plus many more). Muscle also releases a hormone called myokines, which does the opposite of adipokines (discussed previously), and helps to decrease inflammation throughout the body and is health-promoting. The more muscle mass you have, the more of these myokines you will secrete.
The stronger and more muscled you become (note - this does NOT mean you need to look like a bodybuilder) the less risk you have for developing some of the most common chronic diseases that plague our society. This is why RT is recommended at least 2-3 times per week in the physical activity guidelines...it is THAT important. As well, being stronger later in life is indicative of someone who has stayed relatively fit and active throughout life, meaning they probably have participated in other healthy behaviors like aerobic fitness, a healthy diet, or other lifestyle choices that will have a major impact on their risk of mortality. Therefore, overall muscular strength and size, through RT, are simple yet important modifiable risk factors for preventing premature death that are straightforward to address.
But what about old people?
Besides reducing the risk for the previously discussed chronic diseases, RT is a particularly useful health intervention for older folks. Regular participation in RT appears to prevent, or at least slowdown, the waist circumference increases commonly seen with aging (Mekary, 2015), which we know is associated with negative health outcomes. Being stronger also helps keep seniors more independent later in life as they can complete the tasks of daily living with more ease. RT helps to reverse the effects of sarcopenia and osteoporosis, helping to improve balance while reducing the risk of falls and fall-related fractures (Wang, 2017; Cadore, 2013).
There is also a strong relationship between RT and improved cognitive function in older adults, with those training the most on a weekly basis getting more benefit than those training less often (Li, 2018). One study found RT was an effective antidepressant in older people, while also improving morale, quality of life, pain scores, feelings of vitality, and social functioning (Singh, 1997). Another study found that 6 months of RT improved associated memory function, which has an association with developing Alzheimer’s (Nagamatsu, 2012). In summary, RT is a powerful, non-pharmacological intervention with many proven benefits for older individuals.
But pregnant ladies shouldn’t lift, right?
Staying active during pregnancy is extremely important, both from the mother’s perspective and the newborns. Regular participation in exercise during pregnancy can improve aerobic fitness, prevent urinary incontinence and low back pain, reduce depressive symptoms, control excess weight gain and decrease the likelihood of developing gestational diabetes (Nascimento, 2012). An interesting study found that light RT was not associated with any health risks in the newborn, but it did prevent excessive weight gain in the mothers, which can increase the risk of birth defects and chronic health issues later in the child’s life (Barakat, 2009). RT, similar in the case of overweight individuals, is a more accessible form of exercise due to the ability to scale exercise technique, however, the key with exercising during pregnancy is to adjust the intensity to whatever the mother can handle.
Surely strength training for kids is dangerous?
Since this particular topic could easily use its own 3000-word article (which is something I am planning on doing in the near future), I want to keep this section brief enough to get the point across. RT is not dangerous for kids! It does not stunt growth, increase injury risk, lead to burn out, damage growth plates, or anything else that you have been told. In fact, weightlifting has a much lower incidence of injury than nearly all youth sports (Faigenbaum, 2010). Any negative effects have been constantly refuted in the research. For example, a comprehensive position stand on Youth participation in RT which reviewed the available literature said, “A compelling body of scientific evidence supports participation in appropriately designed youth resistance training programmes that are supervised and instructed by qualified professionals” (Lloyd, 2014).
The caveat is that the programs are ‘appropriately designed and supervised’, and takes into consideration the sport, injury history and age of the athlete. With that being said, there is nothing inherently dangerous about the act of RT for adolescents. There are instead a whole host of performance benefits, including increased muscular strength, muscular endurance, power production, better change-of-direction speed and agility, improved balance, stability, coordination and higher speeds of movement, which are all good things for kids participating in sports. As well there are incredible health benefits like a decreased risk of future cardiovascular complications, better weight management, and promotes more healthy lifestyle habits. Finally, it helps to improve the child’s psychological well-being, as well as reduces both the severity and incidence of suffering a sports-related injury (Zwolski, 2017; Lloyd, 2014).
So are there any risks?
As with anything, participating in RT obviously has some risk. These include various musculoskeletal conditions like strains, sprains, acute low back pain, and various tendinopathies. The incidence of injury in ‘competitive’ Olympic Weightlifting and Powerlifting is around 2-4 injuries per 1000 participation hours (Asas, 2017), and serious injuries are quite rare. One would expect these rates would be much lower in RT focused around improving health rather than maximizing performance. To put these numbers into context, recreational running has 3-4.5 injuries/1000 hours, squash is 11-30 injuries/1000 hours, and even gardening is around 1 injury/1000 hours (Parkkari, 2004). The point is that RT is no more dangerous than many common activities people freely enjoy, yet it has more of a stigma around it. The truth is that there is more of a risk with not participating in RT (see above), and with proper implementation, many of these risks can be mitigated (part 2 of this series will address how to properly implement RT).
Closing Thoughts...
RT, which is an intelligently designed plan with the purpose of increasing muscle size, strength and function, is drastically underutilized in the general public. When included in a weekly fitness plan, RT is a potent stimulus for increasing a person's physical ability while decreasing their risk of injury. It is also extremely effective at preventing, and in some cases reversing, many serious health conditions like obesity, type 2 diabetes and cardiovascular disease, many of which are brought on or made worse from sedentary behaviors. Due to RT’s unique ability to increase muscle mass and strength, it is especially useful for aging adults where age-related muscle loss can reduce their independence and increase their risk of falls and fractures. It is also an extremely safe form of exercise, with low rates of injury, and is proven safe for children, pregnant women, and those suffering from chronic pain.
In essence...Stronger people are harder to kill!
Ok ok, I get it...so now what?
The main purpose of this article was to show that there is an overwhelming amount of evidence promoting the use of RT. If you read this article you should have absolutely no doubt that RT is important for you and everyone you know. It is not just important for improving athletic performance but is crucial for promoting health and longevity. There are known risks with not exercising enough (some very severe risks), more so than the risks associated with exercising. So no matter your health status or experience with RT, it is in your best interest to implement some sort of RT program.
This is where it gets difficult for people...what do you actually do at the gym to get these health benefits? Do I use barbells, machines, bodyweight, or bands? What are sets, reps, or mesocycles? What rest periods are the best? Often people do not have the knowledge required to develop and execute a proper program, as well, gyms can be intimidating places and people don’t like to feel silly or out of place. Part 2 of this article series will discuss what you need to know about RT programming. We will discuss what exactly goes into a RT program. This will include things like the science of how we get stronger, programming principles, and example programs to show you what an intelligently designed program looks like. This will arm you with the knowledge to help get you started on your way to a healthier, and stronger, life!