If you’re passionate about fitness (or know someone who is) you’ve probably heard or given advice about what to do at the gym based on research or personal experiences. But not all of the information out there is completely accurate, and what works for one body may not benefit another.

If you’re just getting into fitness, or are looking to ramp up your fitness knowledge, it’s a good idea to double check information and recommendations from others if you want to avoid an injury, overexertion or other negative consequences. Bad advice can slow down your progress at the gym – which could lead you to give up.

Here are five common pieces of bad fitness advice.

1. No pain, no gain

An oldie, but not a goodie.

As you perform weight training movements, tiny tears occur in the muscle tissue. As they heal, you may experience pain known as delayed onset muscle soreness (DOMS). This can promote but is not required to build muscle. DOMS is most common when you’ve tried a new exercise. So, you can successfully work toward your fitness goals without soreness being a part of everyday life.

2. Running or deep squats are bad for your knees

The movements won’t cause knee damage, but using improper form while doing them certainly could.

Muscular imbalances in the body are quite common, but may also cause people to perform exercises the wrong way. This can lead to soreness in the knees, hips or back. It’s best to consult with a fitness professional to assess your movements and ensure you’re using proper form and technique.

3. Fasting before a workout burns more fat

Working out on an empty stomach is not proven to burn more fat and can lead to negative and even harmful outcomes. It may cause blood sugar levels to drop which can make you feel lightheaded or even faint, and can deprive you of the energy you need to get the most out of your workout.

When it’s not getting energy from carbs, your body will dip into its protein and amino acid stores, reducing your overall muscle mass, which results in a slower day-to-day fat burn.

4. Heavy weights will cause women to get too bulky

The first and most obvious rebuttal to this statement is that each person can decide what body composition they desire, and design their workouts to help them achieve those results.

That said, women can have a different hormone profile than their male counterparts, so the chances of a woman achieving a similar muscle mass compared to a typical man are less likely.

Also, women who work out with heavy weights can enjoy benefits such as boosting fat burn while improving bone density, posture and stamina, all while building confidence and enhancing brain function.

5. Weight train to muscle failure

Forcing yourself to perform as many reps as you can until your body can’t do another isn’t the best approach to strength training. It increases the likelihood that your technique will suffer, which will also increase your risk of injury.

That’s not to say that training to muscle failure can’t be used as a tool to maximize muscle growth, but it must be used strategically in periodized workouts. It’s best to seek the advice of a fitness professional and always have a spotter if you’re planning to lift to muscle failure.

The next time you get or give fitness advice, make sure you look at the big picture and be realistic about what makes sense. What does your body need, based on your current age, stress level and injury history? It’s best to do what you enjoy, have a proper health and fitness plan, and don’t be afraid to speak to a fitness professional to help you stay on the right track.