Before your next workout, consider these 11 science-backed benefits of strength training.
1. Lower abdominal fat. In a 2014 study published in the research journal Obesity, Harvard researchers followed 10,500 men over the course of 12 years and found that strength training is more effective at preventing increases in abdominal fat than cardiovascular exercise.
"When people incorporate strength training into their exercise routine, they not only burn calories, but increase lean muscle mass, which stimulates the metabolism," Rebold says. Muscle mass is a major determiner of basal metabolic rate, or the number of calories the body burns per day to sustain physiologic functions.
2. Better cardiovascular health. Abdominal fat (also known as visceral fat) sits in and around the vital organs, including the heart. So, preventing or reducing any excess abdominal fat through strength training can certainly
However, studies suggest that strength training also directly impacts the heart. For example, 2013 research in the Journal of Applied Physiology demonstrates that young men who regularly strength train have better-functioning HDL, or good cholesterol, compared with those who never pump iron. Rebold explains that strength training improves blood pressure and triglyceride levels similarly to cardiovascular exercise, but it has even greater benefits on HDL. And 2015 research published in The Lancet medical journal shows that grip strength (a marker for total-body muscle health) more accurately predicts death from heart disease than blood pressure does.
3. Controlled blood sugar levels. "Resistance training is something we want anyone with Type 2 diabetes to incorporate into their routine," Rebold says. He explains that a 2013 review published in the journal BioMed Research International shows that, in addition to building muscle, strength training also improves the muscle's ability to take in and use glucose, or blood sugar.
"In your muscle cells, you have these transporters that pick up glucose from the blood and deliver it to the muscle cells," Rebold says. "Strength training improves their functioning to pick up a lot more glucose from the blood and into muscle, thereby decreasing blood sugar levels."
4. Reduced cancer risk. Visceral fat not only increases the risk of heart disease and diabetes, but it can also promote cancer development. Research from the journal Oncogene published in 2017 show that visceral fat cells produce high levels of a cancer-triggering protein called fibroblast growth factor-2, or FGF2.
And according to 2017 research published in Therapeutic Advances in Medical Oncology, muscle mass is a strong predictor of cancer treatment outcomes. Muscle wasting is a common complication of cancer treatment and is associated with a higher risk of chemotherapy toxicity, faster tumor progression and lower survival rates.
5. Lowered injury risks. "Having a good muscle base is important for all movement, balance, coordination and injury prevention," explains Dr. Adam Rivadeneyra, a sports medicine physician with Hoag Orthopedic Institute in Irvine, California. "If a muscle is too weak, it puts more stress on its connecting tendon and can result in tendonitis."
Plus, strength training also increases the number and diameter of collagen fibrils in tendons to increase their strength and help prevent injury, according to a 2015 review published in the International Journal of Sports Physical Therapy, a publication of the International Federation of Sports Physical Therapy.
6. Strengthened mental health. Runner's high gets a lot of hype, but strength training also improves symptoms of clinical depression and anxiety. Exercise-triggered endorphins play a role, but strength training also provides an opportunity to overcome obstacles in a controlled, predictable environment, increasing mental resiliency, according to findings from Harvard Medical School.
For the greatest anti-anxiety effects, a 2014 review published in the journal Frontiers in Psychology shows that using low to moderate weights that are lighter than 70 percent of what you can lift for one rep has the greatest effects on anxiety.
7. Improved flexibility and mobility. It's time to rethink your stretching routine. Results from a 2017 study in the journal Isokinetics and Exercise Science show that strength training improves flexibility in both men and women. A previous 2006 North American Journal of Sports Physical Therapy study suggests that eccentric strength exercises may provide the biggest benefit, improving hamstring flexibility twice as well as static stretching. Eccentric exercises are any that emphasize muscle lengthening, rather than shortening. Example exercises might include the lowering phase of a squat or raising the bar during a lat pull-down, Rivadeneyra says.
However, even more important to overall function, fitness and quality of life is mobility, he says. By taking your joints through their full range of motion during strength exercises, you can increase that range of motion over time, he explains.
8. Elevated body image. Sure, exercise impacts body composition and physique, but research, including a 2015 Journal of Extension study of middle-aged and older women, shows that consistent strength training improves body image and perceived physical appearance – no matter the actual aesthetic results.
Improvements in mental health and energy levels, as well as feelings of accomplishment, are the likely catalysts for improved overall body image, according to researchers.
9. Osteoporosis prevention and management. Strong bodies have strong bones, with strength training significantly increasing bone mineral density, Rivadeneyra says. He explains that any weight-bearing exercise in which you're standing and gravity is pulling down on your body lightly stresses and strengthens the bones and muscles. Plus, every time a muscle contracts, it pulls on the bones it's attached to, which stimulates the cells within the bone to produce structural proteins and move minerals into the bone, he says.
So, for the greatest results, prioritize standing weight-bearing, strength training moves such as squats and lunges. In a 2014 Journal of Family and Community Medicine study, just 12 weeks of strength training with squats increased lower spine and femur (thigh) bone mineral density by 2.9 and 4.9 percent, respectively.
10. Boosted brain health. Strength training can improve brain power across a lifetime, but the effects are perhaps the strongest in older adults suffering from cognitive decline. In one 2016 study in the Journal of American Geriatrics, when men and women ages 55 through 86 with mild impairment performed twice-weekly weight training for six months, they significantly improved their scores on cognitive tests. However, when participants spent their workouts stretching, their cognitive test scores declined.
The key might be getting the blood flowing, Rebold says, noting that high-intensity strength training increases the flow of blood, oxygen and other nutrients to the brain. In the study, adults lifted 80 percent of their 1RM, or the maximum amount of weight they could lift for one rep. That roughly equates to the amount of weight they could lift for eight reps without breaking form.
11. A longer lifespan. One of strength training's many benefits include a longer life. The 2015 study in The Lancet found that grip strength accurately predicts death from any cause and, according to a 2017 Current Opinion in Clinical Nutrition & Metabolic Care study, compared to body mass index or BMI, lean muscle mass better measures a person's overall health.
K. Aleisha Fetters, Contributor
K. Aleisha Fetters, MS, CSCS, is a freelance Health & Wellness reporter at U.S. News.