Health Benefits of Resistance Training

While it may seem obvious what benefits resistance training has on the body, there are many benefits that are not mentioned or glossed over in other articles. In this article, we will explore, with brief detail, how resistance training causes positive health adaptations to our body and mind while addressing some of the lower tier changes that are ignored far too often. From physical changes to psychological improvements, we will discuss all adaptations and the extent of each.

What is Resistance Training?

Resistance training is exercise that encompasses anything related to the improvement of strength, muscle due to an external resistance [1]. For example, weight training, calisthenics, resistance band training; anything that increases one’s musculature via some form of resistance.
 

What physical benefits come from resistance training?​

The physical impacts of resistance training on the body are numerous ranging from more obvious musculature changes to more subtle vascular adaptations.

 

Muscular Adaptations

First, the most obvious change, is increases in muscle and strength [1][3][5]. This occurs as micro tears in the muscle fiber (muscle cells) occur via creating damage to the sarcomere (more detailed anatomy of the muscle located in Muscle Contraction)[5]. This increase in muscle, called hypertrophy, is made possible by the increase in size as protein is used to repair and expand the damaged areas caused by resistance training [5]. However, while these changes are obvious, even in the context of muscular adaptation, there are other adaptations that are more subtle and less frequently discussed.

Again, muscular increases are inevitable and easy to see, but the connective tissue between the musculature and the skeletal structure known as tendons also go through some positive changes [2][4][5]. Tendons are most beneficial when they are stiff, because a stiffer tendon leads to better force production from the muscle it attaches to the bone [5]. This adaptation occurs by increasing the amount of collagen in the tendon, increasing the size of the tendon, as well as increasing the density of the tendon (something akin to bone adaptation, as we will see shortly)[5].

 

How does this all increase overall health?

Well, there are many different ways this helps us. Resistance training has a massive benefit for those who are sedentary and especially as we age as the ability to be mobile decreases with a loss in muscle. This process, called sarcopenia, is a process that occurs due to age and can occur from certain chronic illnesses, as well [6]. To attenuate muscle loss, we increase our resistance training, and in doing so, we increase our ability to stay mobile longer and more efficiently. However, not only is this important in terms of preserving unassisted movement, but increasing tendon and muscular strength leads to reduced injury, as well, for young and elderly alike [6][7].

Skeletal Adaptations

So, while we’ve discussed and explained, briefly, the effects of resistance training on muscle and the connective tissue (tendons) we have yet to discuss the impact on the other side of the body’s structural system - namely, the skeletal system. Bones are measured by their diameter, length, and density, but in the case of resistance training, we are most concerned with the diameter and density of bone. There is a direct relationship between resistance training and bone density [8]. However, these adaptations do not appear from thin air.

Basically, bones are in a state of growth (in terms of increased diameter and/or increased density) for the better part of your first 30 years of life; however, as we age and stimulus is not applied to the bones via load (via weight baring movement), the bones begin to withdrawn calcium and fall into a state of loss (decreased diameter and/or density)[9]. However, when we engage in resistance training, just like the muscles and tendons, the body must attenuate for this stress/load and continues to increase bone density by depositing calcium (among other things)[8]. This occurs as bone cells, osteoblasts, become more active than their counterpart, osteoclasts, which lead to an imbalance in favor of bone density increase called bone remodeling [10]. This is site specific, however, so doing enough exercises to stimulate the total body is most beneficial as it will create load on the entire body and this bone remodeling will occur throughout the entire system [8].


How does this all increase overall health?

Osteoporosis is a condition in which the bones have had their density slashed over time and are therefore weaker and more susceptible to breaking [9]. This is most prevalent in the elderly and women, and can be decreased or avoided entirely with the benefit of consistent resistance training [9]. Not only do weak bones have a negative impact on health in terms of limiting mobility, but they can completely incapacitate someone by having a prone area like the wrist, hip, or spine break [9]. Resistance training gives groundwork to stronger bones from early on, but even later in life can encourage bone density to favor osteoblast function and growth in face of an overwhelming osteoclast majority.


Neural Adaptations

It may not be intuitive to think that our nervous system also goes through changes when encouraged to do so, but it certainly is the case. A number of muscle fibers are attached to one neuron, and when that neuron is activated, the muscle fibers contract creating power for resistance training. So, when we engage in resistance training, not only do our muscle fibers change by adapting to load, but the neuron attached to each bundle of muscle fibers adapts, as well.

Neurons can adapt by increasing their “hold” on the fibers by increasing the depth and width of the motor endplate as seen in Neuromuscular Junction & Impulse Transmission. This leads to an increase in muscle body activation, as well as activating the main muscles moved, as well as their “brake” muscles that help stop the movement at the fullest extent of the movement [11]. Not only that, but neurons coordinate firing more synchronously [11].

 

Neuron axon (red arrow) reaching into a motor endplate (blue arrow) to activate the muscle fiber (black arrow).

How does this all increase overall health?

So, neurons activation improves, how does this help us in terms of health? Well, the more synchronous neuron firing occurs, the better power production is created, but more importantly, coordination increases [11]. Not only that, there is evidence that certain types of resistance training (high jumping, for example) increases reflexes [11]. Being able to react more speedily and with a better stimulation to situations like a misstep or a false move would typically lead to an increase risk of injury, minor and major, but with better reflexes and better coordination, it is more likely a person can recover, denying potential injury.

Vascular Adaptations

This is likely far less intuitive, and even as I write this, there is need for more research on this front. However, there is some evidence to show that resistance training leads to positive adaptations of the vasculature [12]. It is true that some of the research is conflicting and therefor a conclusive statement cannot be made at this time, but it seems that healthy populations tend to get benefit by having an improved vascular function (dilation, for example), as well as improved vascular wall thickness from resistance training [13][14]. Meanwhile, those with heart conditions have also been examined and it has been shown that their arterial wall thickness decreases, but this finding may be isolated to this specific condition and not applicable to healthy populations [12][15].

How these mechanisms work fully is yet to be discovered. The idea is that these temporary bouts of high pressure on the body (since resistance training temporarily raises blood pressure) leads to long term positive adaptations. However, the specific of how this occurs is still a rather gray area.

How does this all increase overall health?

This should be relatively obvious, but if the vascular system is healthier, then there is a decrease in risk (one would assume) of diseases like hemorrhagic stroke.


Physiological Adaptations

While, technically, all of the categories we have (and will) dissect in this article are part of human physiology, these two facets of health did not seem to fit in any of the other groups, so excuse the vague title. However, our physiological health is further improved in terms of blood glucose levels (also read as “insulin sensitivity”) and possibly cholesterol levels.

First, the sure; blood glucose levels are decreased by resistance training [16]. Now, while it is true that long duration aerobic exercise is likely still the most recommended technique of blood glucose management, as evidenced in Can you be Obese and Healthy?, it is also true that there is research indicating that resistance training is also effective, and even some research indicating it to be as effective as aerobic exercise [16].

On a separate note, studies have also shown cholesterol markers to be improved from resistance training, but some of these studies need to be redone for reliability purposes [16]. So, at best, cholesterol markers may decrease, but this is not set in stone.

Back to the certainty of blood glucose regulation, this occurs due to increased insulin sensitivity through increasing recognition of insulin, as well as the body adapting by creating more insulin receptors with which the body can shuttle glucose into the musculature [17].

 

How does this all increase overall health?

The more normalized a person’s glucose levels and cholesterol levels are, the healthier the vasculature will be leading to a decreased risk of cardiac events, stroke, metabolic syndrome, among a series of other related potential health issues. Not only that, having normalized blood glucose levels allows us to have consistent energy for day to day activity.



Body Composition Adaptations

Most likely you are aware of this already, but resistance training has a positive effect on the body in terms of increasing muscle size and decreasing fat [16][18]. This is likely not much of a shock, but the mechanisms are intertwined as resistance training puts positive stress on metabolically active muscle tissue, which, after training, not only needs energy to repair and rebuild itself, but uses more energy post exercise than aerobic exercise. This increased demand for muscle adaptation (as described in the “Muscular Adaptation” section of this article) as well as the added demand on the total musculature leads to the body taking energy from fat reserves and increasing muscle size.

How does this all increase overall health?

Apart from looking sexier with your decrease in fat and increased toned look, decreasing fat, within reason, and increasing metabolically active tissue like muscle leads to a decreased risk in almost every single illness known to man (and woman). Having less metabolically inactive tissue (fat) putting strain on the joints, plus increases in muscle for better insulin sensitivity, coordination, strength, mobility, among other benefits is great to have.


What Psychological benefits come from resistance training?​

This is a separate section, because it is a large topic in itself. With mental health as the measure, resistance training shows significant improvements in certain areas and shows some possible benefits in other areas.

Anxiety

Resistance training has a strong impact on general anxiety. People who engage in moderate resistance training tend to see the largest reduction in anxiety, and although aerobic exercise also helps in reducing anxiety, there is no significant difference between the modalities; so, resistance training is just as effective as aerobic exercise to decrease general anxiety [19][20].

Cognition

In terms of cognition, defined as better memory and knowledge acquisition, resistance training also has a significant impact [19]. Not only is brain function improved, but the most dramatic improvements are related to memory and could help stave off dementia in those prone to the disease [19]. Again, although aerobic exercise offers similar benefits, resistance training proves to be a suitable substitute [21].

Chronic Fatigue

This is probably one of the more interesting points in which resistance training strongly impacts health. As a matter of fact, when compared to clinical pharmaceutical remedies, resistance training proved to be significantly better at decreasing chronic fatigue [19]. This is an impressive endorsement of resistance training over other methods of dealing with chronic fatigue as it is shown to be the most potent remedy, bar none.

Self-Esteem

While it seems evident that if a person feels better, most likely they will feel better, and as we know resistance training has a direct impact on body composition, it seems this would be highly likely. Well, the little science that has been done on the subject substantiates that belief. Granted, self-worth and confidence are rather subjective, but with a variety of definitions, it has still been shown that resistance training improves self-esteem [19][22].

Sleep Habits

It almost goes without saying that inadequate sleep leads to a series of health issues from mental illness to poor physical health as sleep controls a massive part of our normal function. Yet again, resistance training seems to attenuate sleep related issues to a degree. It has been seen that people who resistance train have better sleep habits and can improve sleep disorders up to 30% in those suffering from sleep apnea, among other sleep issues [19].​

Depression

Depression is one of those mental struggles that has some differing opinions in terms of the benefit resistance training offers. While no studies conclude that resistance training has deleterious effects, not all saw significant improvements [19]. These discrepancies may due to dose of resistance training offered. In general, it has been seen that depressive symptoms reduce significantly from resistance training [19][22]. We can safely go with the assumption that resistance training does have a strong impact, if the dose is appropriate.

Who benefits from Resistance Training?

Obviously everyone benefits from resistance training considering the massive amounts of benefits, but certain populations would reap more benefit in terms of maintaining their health more efficiently if they resistance trained.

While more and more women are picking up heavy weights and dominating the gym scene, anyone who is not involved in some form of resistance training is severely reducing their potential to be their healthiest. Women can especially benefit from resistance exercise’s strong impact on bone density (discussed in “Skeletal Adaptations” earlier in this article) as they are more prone to osteoporosis especially after menopause.

Anyone suffering from self-esteem issues, depression, or physical illnesses like diabetes as resistance exercise increases self-esteem, likely decreases depressive symptoms, and normalizes blood glucose levels.

The elderly probably see the most drastic preventative benefit from resistance training as they are most prone to osteoporosis injuries like fractures and breaks. Not only that, the combative effects of resistance training on muscular atrophy (muscle size and strength decrease) can lead to improved mobility, regain of appreciable strength, and above all allowing elderly to be self-sufficient and sharper in mind and body alike.


What is enough stimulus for positive adaptations from resistance training?

We have just read about all the amazing benefits connected to resistance training, but if you are not familiar with how to start, that information could go to waste. Do you need to be a bodybuilder or go through brutal exercise programming to see benefits? The answer is a resounding “no”. Now, while this is not the most advanced recommendation, it is the simplest and will offer a person all the benefits listed above if this exercise modality is continued long term; performing resistance training with an intensity of 60-70% of your 1 repetition maximum, 3 sets of 8-12 repetitions per exercise, 1-2 exercises per muscle group, 2-3 times a week, and focusing on properly executed compound exercises when possible (deadlift, squat, bench press)[1].

SUMMARY

There we have it. Resistance exercise, which ever modality you choose within the realm of the term, is extremely beneficial by improving muscle strength, mass, bone density, tendon stiffness, vascular thickness, insulin sensitivity, body composition, among many other physical benefits. Not only that, resistance training has a profound impact on psychological factors like anxiety, self-esteem, likely depression, sleep, cognition, and has an unprecedented, unmatched impact on reducing chronic fatigue. This is especially important for the elderly to take into consideration, because resistance training can keep a person alive longer and with a much higher quality of life.

Writer: Nicolas Verhoeven

                                                                                                            Citations


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