Feature Image by Jonathan Borba

We all know that exercise and a healthy diet are good for us, but it can be hard to know exactly what you should (and shouldn’t) do for a productive fitness routine. To help you achieve your health goals, we spoke to some seasoned personal trainers about all the things you should never do.

From fasting before the gym to excessive amounts of cardio, below are eight things personal trainers never want you to do.

Don’t overdo the cardio
“Constant cardiovascular exercise interferes with the body’s ability to recover from strenuous workouts,” says Eric the Trainer or Eric P. Fleishman, a celebrity fitness expert and host of Celebrity Sweat. “This can often lead to burnout and injury.” Fleishman also suggests that excessive cardio exercise lowers your body’s natural immune system, which can then open up the possibility of contracting colds and viruses. With this in mind, he advises keeping the cardio sessions to 20 minutes a few days per week.

Don’t fast before working out
“You’ll quickly realize how ineffective your physical, cognitive, and processing abilities are without eating food,” Fleishman says. This can cause any weight loss you’re striving for to be short-lived, as once the body switches from starvation mode, it then suddenly switches to turn food into fat.

Don’t eat candy
“Candy is made primarily of sugar, which is the leading cause of diabetes, obesity, and behavioral problems in adults and children,” Fleishman suggests. But if you can’t resist the siren song of sweets, he recommends eating healthier alternatives, such as berries, dates, or Quest Nutrition protein bars. “These choices allow you to enjoy the same flavor and texture of your favorite foods without the sugar and excess calories,” he says.

Don’t skip out on water
“I never want my clients to become dehydrated,” says Steve Stonehouse, USATF-certified coach and director of education for STRIDE. “Dehydration is not only very hard on your body, but it also tricks your mind into thinking that you’re hungry. This can actually cause you to eat more than you’d like.”

Don’t engage in negative self-talk
“Negative self-talk leads to self-sabotage,” says Johnathan Smith, AAAI/ISMA-certified personal trainer and founder of iRobotFit. Praise yourself for what you have accomplished, he advises, even if you start with baby steps.

Never count calories
“Your body will tell you what you need, and this often varies based on your daily activity,” Smith says. You’ll want to pay attention to how you eat and learn to feel how food affects your body.

Don’t compare yourself to others
Despite how tempting it may be, Smith strongly advises against comparing yourself to others. “Your body is unique to you and that’s amazing,” he says.

Don’t use supplements
“Even if they are strongly recommended by a friend, do not use supplements of any kind,” Smith suggests. Supplements are unnatural and may cause water retention, inflammation, and a host of other problems, he explains.

xx, The FabFitFun Team