Heart rate training can be very useful for runners hoping to train more effectively by helping us to avoid those dreaded junk miles. Heart rate monitors can be purchased as chest straps and some GPS watches now even have built-in optical sensors on the wrist.

Since I’ve been training with heart-rate for quite a few years myself, and as an ambassador for Suunto, I often get asked about training with heart-rate. I’ve also realized in talking with people that there’s quite a bit of confusion on how heart rate can and can’t be used.

Here are 5 common mistakes that runners make when training with heart rate.

They say you should play to your strengths and forget about working on your weaknesses. If I could race only uphill or on less-technical downhill terrain, I might follow this advice. I’m tired of getting passed on the really technical stuff though, so I decided to instead seek some advice from one of the fastest downhillers that I know.

I’ve had the pleasure of doing a bit of training with local speedster Mike Murphy, recent winner of the Knee Knacker, who suggested that I try running downhill repeats. This, in addition to doing more functional strength work like plyometrics, could be just what I need to mitigate my major weakness.

When I started running about 5 years ago I jumped pretty much straight into the half-marathon and marathon distance. Far from a high school or collegiate running background here. As I began to follow a formal training plan, I found the tempo runs and speed work to be more difficult than the longer distance runs but I quickly realized how important they are even for marathon performance.