Most people strength train to improve their body composition, but the benefits of working your muscles against resistance go beyond what you see in the mirror. For example, strength training enhances balance and coordination, builds and preserves bone density, improves functionality, and may even have mental health benefits.
But how effective is strength training for fat loss? You might assume aerobic exercise that boosts your heart rate has a clear advantage over working your muscles against resistance but is that the case? A new study says no. It shows that strength training is a fat burner in its own right.
What a New Study Shows about Strength Training and Fat Loss
A number of studies have looked at the effects of strength training on fat loss in the past with mixed results. However, most of these studies had flaws, like small sample sizes, so it was hard to draw a firm conclusion about strength training and fat loss.
A way around this is to look at the results of many small studies, a process called a meta-analysis. That’s exactly what researchers at UNSW Medicine & Health did. They pooled the results of 58 studies focusing on strength training for fat loss and analyzed the results. Based on the results, strength training is a fat burner too and rivals aerobic exercise for fat loss.
There are a variety of ways to strength train, and you might expect that to be a factor in whether strength training promotes fat loss. Duration and volume of strength training would be variables too. There’s a difference between lifting heavy weights for an hour and lifting lighter weights for 30 minutes. Even factors like the number of compound exercises vs. isolation exercises in a workout could have an impact. Compound exercises burn more calories and place greater metabolic stress on the body than isolation exercises.
The subjects in the studies lifted weights for various lengths of time but average between 45 and 60 minutes per strength training session and they strength-trained an average of 2.7 times weekly. Based on the analysis, the strength-training subjects lost an average of 1.4% of their total body fat. That’s a respectable amount of fat loss, especially when the participants did no cardio.
This study shatters the myth that strength training isn’t beneficial for fat loss. In fact, it can be an alternative to cardio for people who can’t do cardio for one reason or another. As the researchers pointed out, strength training offers benefits they thought only came from aerobic or cardiovascular exercise.
Don’t Ignore Cardio Either
This doesn’t mean you shouldn’t do cardio. Cardiovascular workouts have some benefits that you won’t get with strength training, or the benefits will be less pronounced. Cardiovascular exercise is any physical activity that uses large muscle groups in a steady, rhythmic manner for an extended period of time. In other words, it’s any exercise that gets your heart rate up and keeps it there.
Cardio exercise increases the body’s demand for oxygen, thereby improving cardiovascular performance and strength. For example, cardio is still the best way to improve aerobic capacity, how efficiently you deliver oxygen to tissues and the efficiency with which your tissues use it. Greater aerobic capacity means better stamina and endurance. But strength training does appear to have benefits for fat loss.
Plus, your heart is a muscle, and like all muscles, it needs exercise to stay healthy. Cardiovascular exercise — any activity that increases your heart rate and keeps it up for a period of time, improves your heart’s efficiency. Some studies show that regular aerobic exercise can add years to your life and lower your risk of chronic health problems.
Include Both Strength Training and Cardio in Your Fitness Routine
Fortunately, you don’t have to choose between strength training and cardio. Including both in your routine is the key to maximizing your overall health and fitness benefits. You could strength train and do cardio on alternate days to ensure fatigue doesn’t interfere with your performance for either.
How much and how often you strength train and do cardio should depend on your goals. If your main objective is to become stronger and build muscle size, you might strength train 3 days per week and only do cardio on two days. If building strength, while losing body fat, devote more time to strength training and less to cardio.
Strength Training Tips for Maximizing Fat Loss
If you want to get leaner, here are some tips for adapting your strength training to help you do so:
Do a ratio of compound to isolation exercises of around 4 to 1. Compound movements are movements like squats, deadlifts, and bench presses that work multiple muscles at once. Isolation exercises are single-joint moves like curls and triceps extensions that target specific muscles.
Lift heavier weights during (70-85% of your one-rep max) during some sessions. This will increase excess post-exercise oxygen consumption (EPOC), leading to greater calorie burn even after your workout is over.
Focus on nutrition, as it determines 80% of your body composition. Increase the protein content of your diet and reduce refined carbohydrates and sugar. This approach will help you build muscle and reduce fat storage by improving insulin sensitivity.
Get other parts of the equation right too – adequate sleep and stress management to keep cortisol under control.
The Bottom Line
Now you have another reason to lift weights; it can help you lose body fat. Plus, it builds strength and lean muscle. But if you want a balanced workout, do both.
- Michael A. Wewege, Imtiaz Desai, Cameron Honey, Brandon Coorie, Matthew D. Jones, Briana K. Clifford, Hayley B. Leake, Amanda D. Hagstrom. The Effect of Resistance Training in Healthy Adults on Body Fat Percentage, Fat Mass and Visceral Fat: A Systematic Review and Meta-Analysis. Sports Medicine, 2021; DOI: 10.1007/s40279-021-01562-2.
- Westcott WL. Resistance training is medicine: effects of strength training on health. Curr Sports Med Rep. 2012 Jul-Aug;11(4):209-16. doi: 10.1249/JSR.0b013e31825dabb8. PMID: 22777332.
- “The BEST Resistance-training Program for Fat Loss.” 05 Dec. 2017, https://www.acefitness.org/education-and-resources/professional/expert-articles/6868/the-best-resistance-training-program-for-fat-loss/.