Why Resistance Exercise is so Important

We all know how important physical activity is. It can feel like the default recommendation when you go to a doctor or provider, to the point that it almost becomes a joke of whatever you are seeking help for, exercise is the answer.

While this is generally good-faith advice, the issue I see is that people aren’t sure what exercise they actually should be doing. In a society that prioritizes productivity over everything else, it can be hard to set aside time to exercise, especially when you aren’t sure if it is the “right” kind. Couple that with decision fatigue and body dysmorphia, and it’s no wonder why people struggle to get started.

Resistance training has become a gendered exercise routine - at the detriment of women across the US. Exercise gets marketed to women as expensive workout classes, matching workout sets, pink weights, and cardio above all else. Women are 3 times more likely than men to fracture a hip, partially due to hormonal changes during menopause accelerating bone loss. Lack of functional strength - such as the inability to stand from a chair without using your arms - puts you at higher risk for fracture.

The major benefits of resistance training can be summed up into improvements in mental health, metabolic health, bone health, and strength.

Resistance training is any form of exercise that requires your muscles working against a force or weight. This could consist of lifting weights, whether free weights or using a weight machine, using resistance bands, body weight activities such as squats or pushups, plyometrics, stair climbing, or even aquatic exercises. Walking, while a great form of exercise overall, wouldn’t be classified as resistance training.

The first benefit of resistance training is as a part of a depression and anxiety treatment plan. While medication and therapy are typically the first line of treatment, research shows that medication is minimally effective for mild to moderate depression symptoms. Therapy can also be expensive, time-consuming, and difficult to access. Exercise has been shown time and time again to improve depression and anxiety symptoms due to improvements in inflammation, stress hormones, and insulin-like growth factor (IGF-1). Resistance training especially has been highlighted recently for its mental health benefits. What is it about resistance training specifically that may provide increased benefit?

Well, we cannot talk about mental health without talking about metabolic health - there has been shown to be a strong positive correlation between depression and metabolic disorders such as obesity, diabetes, and cardiovascular complications. More muscle mass is associated with increased insulin sensitivity - that means less insulin resistance. Skeletal muscle is responsible for the majority of glucose uptake in the body. The less glucose in your bloodstream, the less insulin released, and the lower risk of insulin resistance over time. My take is that with the improvements in metabolic health with resistance training, this doubles down on the mental health improvements.

Bone health is typically seen as something that only older adults have to worry about. And, admittedly, your risk for something like a hip fracture is significantly lower in your 20’s and 30’s than in your 70’s and 80’s. However, after age 25, your overall bone mass begins to decline. So what does resistance training do for this?

The answer lies in one of my favorite phenomena known as Wolff’s Law. Wolff’s Law states that bones will adapt based on mechanical loading - essentially, the stress placed on the bone via weight bearing or tendon activity will cause it to grow stronger over time. When you are lifting a dumbbell during a biceps curl, the stress of the biceps tendon pulling on the humerus causes the body to lay more bone material down. The more bone you start out with, the better protected you will be against osteopenia, osteoporosis, or stress fractures.

Finally, resistance training increases strength. Although this seems trivial in comparison to the other benefits I spoke about, it’s incredibly important. Lower muscle mass is independently associated with increased all-cause mortality - this means regardless of how active you are, if you are not focused on building muscle strength, you aren’t getting those benefits.

Anecdotally, I’ve seen in my patients that resistance training improves their pain intensity and duration. The research backs this up as well.

The American College of Sports Medicine (ACSM) provides some very helpful guidelines on how to get started - engaging in progressive strengthening activities involving major muscle groups 2-3 times per week, with 2-3 sets of 8-12 repetitions. What could, then, be a realistic split? One day per week focusing on upper body, one day focusing on lower body, and one day per week on compound or functional exercises.