Here's what lifting weights really does to your body

The idea that lifting weights makes women (especially) bulk up like Arnold Schwarzenegger in his heyday is as tough to budge as a 350-pound barbell. But adding weights to your workout provides health benefits beyond building muscle, says Kaley Hatfield, a certified professional fitness trainer and professional dancer in Los Angeles who hosts virtual workout classes at KaleyHatfield.com. "When people think of weights, a lot of times they correlate that with 'bulking' or bodybuilding, but there are endless benefits to lifting weights that don't include either of those," Hatfield tells HealthDigest.

Weight-lifting actually shapes the body, adds Jacque Crockford, CSCS, a spokesperson for the American Council on Exercise in San Diego, California. We look toned and fit not just by burning off excess fat but creating a muscular base. "Lifting heavy weights is a great way to get the shape of the body that you may be seeking," Crockford says (via Shape). "Want a perkier bum? Do squats and deadlifts. Want more defined arms and back? Do some shoulder presses and pull-ups."

You won't get that bulky look unless you also bulk up your diet by consuming extra calories. Rather, lifting weights helps you burn calories and heightens your body's fat-burning capabilities. "Lifting weights is obviously going to help you burn muscle, but by building muscle, you're shredding fat and also keeping your body in a fat-burning stage longer, meaning you can lift weights in the morning and will continue burning fat all day long," Hatfield says.

Lifting weights boosts bone density and metabolism

While you're gaining muscle, consider these other perks to adding kettlebells, dumbbells, or deadlifts to your workouts. Lifting weights improves posture, Hatfield says. Granted, good posture is tough to maintain all day, especially if your job involves sitting. But it becomes easier if you build strength in your upper back, shoulders, and core. Some exercises to do this include the halo, where you grip a dumbbell at each end and slowly circle it around your head (via Self).

Lifting weights also increases bone density and boosts metabolism, Hatfield says. The Mayo Clinic agrees, noting that lean muscle mass naturally diminishes with age. Strength training enhances muscle mass, decreasing that age-related gain in body fat and revving up your metabolism (via the Mayo Clinic). Strength training also places just enough stress on your bones to increase bone density, reducing the risk of osteoporosis.

Lifting weights consistently improves your immunity

Lastly, lifting weights helps your body fight off illness, Hatfield says. Although strenuous exercise such as training for a marathon can wear down your immune system, studies show that other exercises, such as walking and weight-training can help you ward off colds and flu — and reduce the intensity of your symptoms (via Oxygen). One study in the British Journal of Sports Medicine noted that adults who exercised at least five days a week spent 43 percent fewer days suffering from upper respiratory tract infections than those who were active only one day or less per week.

The key is consistency, adds Pete McCall, an exercise physiologist, founder, and host of the "All About Fitness" podcast. People who start strength-training for the first time or who don't train regularly will experience a stress response as the body tries to determine the best way to produce the energy it needs both for exercise and supporting the immune system, he told Oxygen.

If you're consistent and build intensity gradually, your immune system will strengthen along with your muscles, McCall says. "[I]t takes a period of adjustment of about four to six weeks for your body to learn how to do this," he told Oxygen.