The Metabolic Advantages of Strength Training
Cardio (aerobic) exercise usually gets the most press for metabolic health, but did you know strength training is just as important? Here’s why adding strength training to your workout is a powerful way to optimize metabolic health.
It’s no secret that we are obsessed with metabolic health. Metabolic health refers to the efficiency with which your body produces energy. A healthy metabolism is essential for maintaining a healthy weight and preventing chronic diseases, such as heart disease and diabetes.
A quick Google search for “metabolic health” yields hundreds of thousands of results, so we aren’t the only ones interested.
And while there’s a lot of focus on foods and cardiovascular exercise for metabolic health, there’s one crucial aspect that’s less talked about:
Strength training (or resistance training) is any type of physical activity that involves using your muscles to work against a force, whether it be gravity, a resistance band, or a set of dumbbells.
Strength training is just as essential (and in some cases, maybe even more helpful) as cardio for keeping your metabolism functioning optimally.
In this article, we’ll review the evidence supporting the metabolic benefits of strength training and then provide some tips on how to get started with strength training or improve your current routine.
<p class="pro-tip"><strong>Read more about </strong> <a href="/blog/metabolic-health">what metabolic health is, and how to improve it</a>.</p>
Metabolic Health and Strength Training: The Big Picture
To help understand why resistance training can support metabolic health, let’s look at what happens to our bodies and metabolism with age.
As we get older, muscle mass gradually declines. This process begins around the age of 30 and progresses steadily throughout our lifespan.
The loss of muscle mass is accompanied by a decrease in muscle strength and function, leading to inactivity, even for healthy adults.
What’s more, the loss of muscle mass and strength that occurs with age can affect metabolic health.
Muscles are metabolically active tissue that require energy (in the form of calories) to maintain their structure and function. So, as we lose muscle mass, our bodies need fewer calories to function.
This decrease in calorie requirements coupled with lower activity levels can mean less muscle mass, extra fat mass, and an increased risk of developing metabolic syndrome. Metabolic syndrome is a group of conditions like high blood sugar and cholesterol, that increase the risk of developing heart disease and type 2 diabetes.2
The good news is that strength training can help to offset the age-related loss of muscle mass and improve metabolic health. Sadly, only 17 percent of U.S. adults include at least two resistance training sessions a week as part of their wellness routine.
If you aren’t incorporating any (or not enough) weight training into your weekly routine, this may be your sign to start.
<p class="pro-tip"><strong>Learn more about </strong> <a href="/blog/age-glucose-levels">the link between age and blood sugar</a>.</p>
How Strength Training Affects Metabolic Health
Many metabolic health markers are affected by strength training, including:2
- Body weight and waist circumference
- Blood sugar levels
- Blood pressure
- Lipid profile like cholesterol and triglycerides
- Biomarkers of inflammation
How Often Should You Strength Train for Metabolic Health?
A few studies suggest the more someone strength trains, the more they can expect to see changes in these metabolic health markers. In other words, strength training appears to have a dose-dependent relationship with metabolic health.
But, there are still questions about whether bumping up frequency or intensity (like using heavier weights) is more beneficial. Some studies suggest that even small amounts of strength training can help, so what’s most important is just getting started!2
Thinking about strength training can feel intimidating or bring up images of muscle-bound gym rats if you’re new to the world of weights. But here’s the thing: you don’t have to lift 50-pound weights to see results. Body weight, resistance bands, or light dumbbells are a great place to start, especially if you are a beginner. And despite what you’ve heard, strength training won’t make you bulky (unless you train and eat for the purpose of getting bigger).
If you exercise but only participate in cardio, you may miss out on some of the benefits that strength training can provide, so it’s best to combine both.
Let’s take a closer look at why it’s important to add strength training to your routine and how it supports metabolic health.
<p class="pro-tip"><strong>Try this </strong> <a href="/blog/dumbbell-leg-workout">10-minute dumbbell leg workout</a>.</p>
Strength Training Increases Metabolism
Resting metabolic rate (RMR) is the number of calories your body burns at rest. It’s influenced by a number of factors, including muscle mass. Muscle mass can increase RMR (hint: strength training builds muscle mass).
One of the main ways that strength training supports metabolic health is by increasing muscle mass. Less muscle mass means our body uses less energy, which is one of the main reasons metabolism drops with age. Along with drops in RMR, fat mass increases as muscle mass declines.
But resistance training can help, and it doesn’t take hours at the gym to make a significant difference. Even one workout a week can be enough to boost metabolic rate.
Further, muscle protein turnover increases when you participate in resistance training, which means your body uses more energy to regenerate and repair muscle tissue. And the more energy you use, the more calories you burn.
Even though many people assume that long cardio sessions are needed to burn a lot of calories, resistance training keeps the calorie burn going for hours after you’ve finished exercising.
A study comparing steady-state cardio to resistance training and high-intensity interval training (HIIT) found that people who participated in resistance or HIIT training burned significantly more calories in the day after exercising than the aerobic group.
In other words, strength training can help you maintain a higher metabolism, reducing the impact of metabolic and muscle losses usually linked with aging.
<p class="pro-tip"><strong>Learn more </strong> <a href="/blog/boost-metabolism">natural ways to speed up your metabolism</a>.</p>
Strength Training Can Improve Cholesterol Levels
Cholesterol is a type of fat essential for cellular structure and function. There are two main types of cholesterol:
Low-density lipoprotein (LDL) cholesterol: Often referred to as “bad” cholesterol, high LDL cholesterol levels have been associated with an increased risk of heart disease, although research has questioned the connection recently.
- High-density lipoprotein (HDL) cholesterol: Often referred to as “good” cholesterol, high HDL cholesterol levels are considered protective and associated with a reduced risk of heart disease.
Even within these two categories, there is a bit of nuance where specific sizes of each type of cholesterol may not be as harmful as others. Still, overall cholesterol is considered an important biomarker for cardiometabolic health.
Any exercise can support healthy cholesterol levels, but strength training may give extra support. One study found that resistance training significantly reduced total and LDL cholesterol and several other markers of metabolic health.4In this study, a higher workout volume (6 sets) was even more beneficial than a lower volume (3 sets).
Another study found that resistance training helped increase HDL regardless of intensity, but working out three times a week led to a more significant reduction in LDL.2The authors of this study also concluded that people with high cholesterol may see greater improvements than those with more normal levels.
Cardio plus resistance training may be your best bet, as health experts suggest combining the two produces optimal results for cholesterol improvement.
Resistance Training May Improve Triglycerides
Triglycerides are a type of fat found in the blood. High levels of triglycerides are associated with an increased risk of heart disease.
Exercise, especially aerobic exercise, can help to reduce triglyceride levels, but the effect of strength training on triglyceride levels is less clear.12 Some studies have shown that strength training can reduce triglyceride levels, while others have found no effect.
The discrepancy is likely because triglyceride levels are affected by a number of different factors, including diet and genetics. But weight loss can significantly lower triglycerides, so resistance training may indirectly reduce them by improving body composition.
Strength Training May Reduce Waist Circumference
Waist circumference measures the widest part your stomach (around your belly button) and is a predictor of mortality (even when BMI is considered normal). A waist circumference of 35 inches or more in women and 40 inches or more in men is considered high risk.
Exercise can help reduce waist circumference, but strength training proves to be especially effective. One study comparing the effect of aerobic exercise to resistance training found those following the resistance training program saw more significant changes in waist circumference.
Resistance exercise may be more helpful for waist circumference because of its impact on metabolism, insulin sensitivity (which we will explore below), and reductions in overall fat mass.9
Resistance Training Can Lower Your Blood Pressure
Strength training may help lower systolic and diastolic blood pressure by improving blood flow throughout the body and by supporting the structure and function of blood vessels.
One study found that ten weeks of 20 minutes of strength training plus 20 minutes of aerobic exercise led to positive blood pressure changes for people who worked out 2 or 3 sessions a week.9
If you have high blood pressure or take blood pressure medications, it’s always a good idea to check in with your doctor before starting an exercise program. Your health care professional can help determine the right frequency and intensity exercise that is best for you.
Resistance Training Helps with Blood Sugar Management
Resistance training provides impressive benefits for blood sugar balance, primarily by improving insulin sensitivity.
Insulin is a hormone that helps to regulate blood sugar levels. When insulin sensitivity is impaired, cells don’t take glucose out of the blood as efficiently. As blood sugar rises, it can increase diabetes risk and make it more challenging to lose weight.
Aging is often accompanied by an increased risk of blood sugar dysregulation, so older adults may be able to reduce the impact by adding resistance training to the mix. Resistance training can lower A1c, a measure of glycemic control, possibly even more than cardiovascular exercise.
One study found that a resistance training program that included 3 sets of 7 exercises reduced A1c by 18 percent (compared to aerobic training, which lowered A1c by 8 percent) for previously inactive adults.21But once again, combining the two—cardio plus resistance training—can optimize your results.
One thing to note: if you use a continuous glucose monitor (CGM), you may notice that your blood sugar temporarily rises after exercise. This is a normal, short-term response related to releasing stress hormones during exercise. Over time, strength training can help to improve blood sugar control.
<p class="pro-tip"><strong>Learn more about </strong> <a href="/blog/increase-insulin-sensitivity">how to improve insulin sensitivity</a>.</p>
How to Reap the Metabolic Health Benefits of Strength Training
First, a disclaimer: if you are brand new to fitness, it’s crucial to get a medical clearance and work with someone (or follow a program) to ensure you keep your body safe, especially if you have health concerns or take any medications.
The intensity and duration of resistance training required for metabolic health benefits depend on your current fitness level and any health conditions you may have. If you’re new to strength training, start with a lower intensity and shorter duration and frequency. As you get used to this pace, you can being to increase intensity, duration, and frequency.
For general metabolic health benefits, 2 to 3 resistance training sessions per week, each lasting at least 20 minutes, appears to be baseline beneficial according to the above research.
Some think real-life activities like carrying groceries or a toddler doesn’t count as exercise. But they do! They don’t necessarily give you the same results as regular resistance training, but they can be a good first step to getting your body moving.
Functional resistance training that strengthens your core, legs, and back can help your body adapt to these daily movements, so you don’t accidentally tweak your back the next time you give your child a piggyback ride or carry a heavy object.
Starting to feel motivated? Great! Here are a few tips to help you get started with (or improve) your strength training program:
If You Already Have a Strength Training Plan
Resistance training can be as hard or as easy as you make it. If you feel like you’ve hit a plateau in your strength training, then it’s time to change things up. You can add more weight, reps, or sets to your workouts. You can also try a different type of strength training, such as circuit or interval training.
When in doubt, working with a personal trainer or signing up for group classes at a gym can be a great way to level up your training plan.
<p class="pro-tip"><strong>Learn more about </strong> <a href="/blog/metabolic-workouts">using metabolic workouts to boost your metabolism</a>.</p>
If You Do Resistance Training Occasionally
Ever felt delayed onset muscle soreness or DOMS after taking some time off? I think we all have Resistance training feels best if you are consistent. Even one extra session a week can make a difference.
Listen to your body and don’t push yourself before you’re ready. Slow and steady increases in training frequency and difficulty are the key to success.
If You Never Do Resistance Training
If you’re new to strength training, start slowly and gradually increase the intensity of your workouts. A personal trainer can be a great asset when starting a new exercise routine. They can help you learn the correct form for different movements and make sure you are using the proper amount of weight.
If you don’t have access to a personal trainer, resources are available online and in libraries that can help get you started. And if you don’t have access to weights, body weight exercises, such as push-ups, pull-ups, and squats, are a great place to start.
Key Takeaways: Resistance Training Is a Big Part of Metabolic Health
Adding strength training to your workout routine has many metabolic health benefits, including improved insulin sensitivity, blood sugar control, and lipid levels. The intensity and duration of your workouts will depend on your current fitness level.
For general metabolic health benefits, aim to do at least 2 resistance training sessions per week, each lasting at least 20 minutes. Nutrition, stress management, and sleep are also important. Still, you can choose to focus on making resistance training a regular habit and then work on other aspects.
If you’re new to strength training, start slowly and gradually increase the intensity of your workouts and check in with your doctor. A personal trainer can be a great asset when starting a new exercise routine.
<p class="pro-tip"><strong>Keep learning: <ul><li></strong> <a href="/blog/lifting-weights-to-lose-weight">How resistance training can accelerate weight loss (podcast)</a></li> <li><a href="/blog/how-many-calories-are-burned-weightlifting">How many calories are burned weightlifting</a></li> <li><a href="/blog/anaerobic-exercise">14 health benefits of anaerobic exercise</a></li></ul></p>
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