Guys approach lifting weights for many different reasons. Aesthetics inspire some, while others seek to boost sports performance or simply counteract a sedentary lifestyle. Certainly all of us want to minimize the potential for injury and long-term deterioration as we get older.

Lifting weights is effective for all of those goals and more. But even savvy gym rats don’t always realize all of the many benefits—and repercussions—of hitting the iron. Read on for 20 things you may not know about strength training.

1. It boosts joint health

Lifting, especially multi-joint movements like squats and lunges, counteracts the effects of spending long hours hunched over a computer or behind a steering wheel. By opening up the hip flexors, you’ll be less likely to develop back problems.

2. Supersets build endurance

Lifting is most effective when done continuously rather than resting between sets. Perform a pushing exercise, such as a bench press, and follow it immediately with a pulling exercise, such as a dumbbell row. When one set of muscles is working, the other set is resting.

3. It boosts your metabolic rate

Lifting boosts metabolism, especially your resting metabolic rate. Translation: You continue to burn calories at a high rate throughout the course of the day, and even while you sleep. Combine this with a clean diet, and you’ll experience dramatic results.

4. It enhances performance on the field

Lifting boosts sports performance. Strength, especially functional sport-specific strength, is created in the weight room. It’s hard to believe that only a generation ago, few basketball, soccer, or baseball players lifted weights.

5. It builds denser bones

Lifting helps prevent osteoporosis. We lose muscle and bone mass as we age, and that’s especially true for women, who are more prone to the condition. Strength training forces the muscles to adapt by becoming bigger and stronger. Since your bones are the framework that supports those muscles, they’ll become stronger, too.

6. It promotes heart health

That’s because strength training boosts blood flow and decreases blood pressure. Studies of seniors consistently have shown that those with more muscle mass are less likely to die of heart disease.

7. It's tough for women to "bulk up"

It’s impossible for women to get “too bulky” from lifting. Even with the popularity of CrossFit, many women still shy away from heavy weights in the gym. Unless a woman turns to testosterone, she won’t obtain a bodybuilder look. To get the toned physique she wants, however, she needs to lift challenging weights.

8. Your girlfriend's muscles recover faster

Women have some advantages over men when it comes to lifting. For one thing, their muscles recover faster. That’s because they regenerate ATP, the chemical that provides the energy for muscle movement, faster than guys do.

9. Lifting helps you torch more fat

Lifting and other anaerobic activity is more effective than steady-state aerobic exercise for fat loss and building strength.

10. It helps you stay lean

Lifting will increase your lean body mass, which is the key to a healthy physique. After the age of 25, we lose a pound of lean body mass each year unless we do something about it. For each pound of extra lean body mass you have, you burn an extra 50 calories a day.

11. It amps your aerobic system

Even though lifting is not aerobic exercise, you can get some aerobic benefit from the workout since your heart rate increases and never falls below a certain aerobic zone. This, of course, only occurs if you hammer continuously through a circuit and don’t take minutes between sets checking your phone.

12. You don't need equipment

A bodyweight workout of just pushups, dips, and burpees can be as tough as anything with iron.

13. It's efficient

Unless you’re a bodybuilder, there’s no need to spend hours a day lifting. An effective, continuous circuit can be completed in as little as 30 minutes.

14. It will make you a better runner

Lifting will make you run, swim, or bike faster. Triathletes know the secret to faster times is not always more endurance work, but rather working on building relative power through lifting.

15. It prevents injuries

About 65% of injuries come from overuse—repetitive use of joints rendered dysfunctional by muscle imbalances. While lifting with improper form can cause injuries, lifting to strengthen the shoulders, lower back, and hips helps prevent injuries.

16. Hypertrophy = gains in mass

Lifting lighter weights for many reps can be just as effective for building muscle and strength as heavy weights for fewer reps. The key is to lift to the point of fatigue.

17. It makes you flexible

Lifting can improve flexibility. Though the stereotype of the bodybuilder who can’t touch his toes is well-founded, lifting can improve flexibility. The key is to go through a full range of motion at the hips, midsection, and shoulders with each exercise.

18. It can improve your sex life

Lifting improves a guy’s sex life, and not just because of his chiseled physique. Weight-lifting causes the body to produce testosterone, which has no small influence on sex life. Plus, lifting produces greater stamina and strength, two things that come in handy in bed.

19. You don't need to put on weight

Lifting for muscle does not always mean more strength and power. There is a misconception that to become powerful you need larger muscles or more weight. Instead, lift for more power. If a 175-lb athlete drops to 160lbs, but maintains the same power and strength, his relative power has skyrocketed.

20. You need to cross train

Lifting is only one way to build strength and power. Consider that, at the NFL scouting combine, the only lift football players perform is the max 225-lb bench press. Some of the biggest, most explosive athletes in sports spend far more time on speed, quickness, agility, and movement skills.