With so much information floating around these days how can you tell what’s right and what’s wrong? Sometimes it’s hard to make this distinction, even when you’re talking to or reading from credible sources. However, there are some facts floating around that are absolutely not true—next time someone tells you these myths are fact you can set them straight.

1. The treadmill is better for your knees

Starting off his workoutThe force of your body weight coming down onto your knees is what causes most of the damage or pain that runners experience. Therefore, whether you’re on a treadmill or the sidewalk, the impact is the same. If you have bad knees, use the elliptical or stationary bike a few times a week instead.

2. No pain, no gain

This is one of the most dangerous myths. Feeling pain during and after exercise could be a clear sign that you’re doing or have just done something wrong. If you feel sharp pains during your workout stop, take a minute and try again. If you feel that same pain, stop altogether and contact your doctor. If you’re feeling pain after the workout—i.e. extreme soreness—you may have pushed too hard. When you push your body too hard you risk pulling a muscle or hurting yourself by lifting weights that are too heavy for you to handle just yet.

3. Women get bulky when they lift weights

While you may grow firmer, and get bigger muscles, women will never bulk up like men without help from supplements—women lack the necessary hormones. However, lifting heavy weights for minimal reps, think 20 pounds for 6 to 8 reps, will help you burn double the amount of calories than if you lifted 10 pounds for 15 reps. Don’t be scared of the weight room, you’ll be surprised at how quickly you slim down.

4.  More sweat means you had a better workout

sweating young man with a towelYour body releases sweat to regulate internal temperature and cool the body when you’re hot during a workout. While you can have a good workout that makes you sweat a lot, it’s unlikely the inverse is true. Focus on creating tough workouts that push your limits to be sure you’re working as hard as you should be.

5. Longer workouts are better

With the rise of tabata workouts and HIIT, people are learning that you don’t need to be in the gym for two hours a day to see results; you don’t even have to be in the gym for an hour to get your body where you want it to be. High intensity workouts burn more calories and thus more fat than long, slow workouts—bonus: you don’t have to ditch out on those plans you made last week.