Whenever I meet someone who is knowledgeable about a certain topic, whether it is my car mechanic or a bio-ethicist, I try to ask them questions and learn from them. I figure the more people you encounter, the better equipped you are to make your own conclusions.

When I sat down with Chris Lupo and Minde Erickson, two personal trainers from Gold’s Gym, I asked them to give me some fitness tips. I wanted to know if they had any specific things that they really wish people knew, or misconceptions about fitness that they wanted to clear up. Here are some random insights that they wanted people to know.

MYTH: Resistance training and weight lifting causes bulk.

LUPO: Don’t just do an hour of cardio. You are losing lean body mass. Women are the worst offenders.If people look bulky it’s because they have fat on top of their muscle. Muscle is lean.”

MYTH: Diets and focusing on toning one body part will get you good results.

ERICKSON: Diets don’t work. Just learn to make healthy eating a lifestyle. You can’t spot-reduce. Your goal should be overall fitness. (Spot-reducing is when you choose a specific part of your body that you want to target for fat loss. For example, stomach, thighs, or backs of the arms. It just doesn’t work that way when it comes to losing fat.)

So when you’re tempted to skip the lifting in favor of cardio or crash diet to tone up your abs, think again. You heard it from the pros: it just won’t work.