Confused? Well, I would have been as well if it wasn't for a doctor's appointment I had a couple of months ago. Not to get too personal with you, but I'm a healthy 22 year old who consistently runs 60-70 miles a week. Being in what I'd like to think is good shape, I was actually excited to visit the doctor a couple of months back; thrilled to hear years of medical training tell me that the only thing wrong with me was a slow heart beat from good ol' exercise. Instead, my doctor was alarmingly concerned by my running habits. He suggested I cut my mileage down to at most 20 miles a week. Why did he make this suggestion? He said that lots of endurance training can actually be bad for your heart. When I read this article this morning I couldn't help but mention it.

Research

One study has shown that about 12% of marathon runners have some scarring of heart tissue. It also showed in a follow-up that the rate of coronary heart disease was significantly higher in marathon runners when compared to controls. Further, it was stated that an increased instance of atrial fibrillation was seen in endurance athletes. This information comes from a recent review by the Mayo Clinic.

Experiment

Is there a threshold where exercise actually has negative consequences?

IF you consistently do aerobic exercise 7 days a week, THEN your body will start to break down.

That could mean you get sick or injured. 

Comment below with your thoughts or a suggestion for a better experiment!

Image by lululemon athletica