We’re constantly bombarded with health rules from our doctor, personal trainer, and even friends, including “Drink eight glasses of water a day” and “Exercise five times a week.” But experts warn that if you have certain conditions, following these rules could backfire. For example: 

  • A lot of us hear “Go for a daily outdoor walk” to get fit and reduce stress. But it could be a killer if you have heart disease. That’s because studies show that if it’s a high-smog day, tiny particles in the air can boost your risk of heart attack. Before you lace up your sneakers, check AirNow.gov for the local air quality. If the air quality index is over 101, experts suggest moving your workout indoors and run the AC. It can slash indoor pollutant levels by up to 50-percent. 

  • Also asthma sufferers, here’s a health rule you might want to ignore: Swim for a good low-impact work-out. If you have asthma, the chlorine can quickly trigger an attack. And in children, too much chlorine exposure can even raise their odds of developing asthma in the first place. So skip swimming if you have trouble breathing. And parents, make sure your children flat out avoid pools with a strong chlorine smell. That often means the pool is over-chlorinated, which makes it an even greater asthma trigger. 

  • Then it’s true that eating leafy greens every day is good for you, unless you’re taking the blood thinner warfarin, also known as Coumadin. That’s because foods like kale and spinach are packed with Vitamin K, which helps your blood clot. So it can make your a blood thinner useless. So limit leafy greens like kale and spinach to one serving a day - max.