I've recently just joined a gym normally I run outside. I've checked my heart rate while running and it's been at 188. I wasn't really tired and didn't feel like I couldn't run anymore I just checked because my face felt really hot. I wasn't really concerned until I said something about it my sister. We were talking about this 5k run and I said I'd like to do it and I started talking about my dad at the gym. She has athletic asthma, but I don't think I don't have too much or a problem breathing while I run. Is this something I should be worried about and if it is what do you think it is and should I stop going running all together?

Before starting any type of fitness program you should get the OK from a physician (get a physical), that way you will know for sure if you have any thing to be concerned about. Make sure you tell the physician what you were experiencing. Also, how were you taking your HR? Manually or with an electronic HR monitor (Polar as an example)? If you use a HR monitor, the batteries may need to be replaced (this happened to me a few weeks ago).

Don't stop running unless you are under doctor's orders.

In theory, your maximum heart heart is 220 - your age, but this is a guideline, and people who are fit can exceed this without distress.

As the previous poster said, how you take the heart rate makes a difference, some monitors are not that accurate.

As a general rule, you are close to max when you are going flat out, unable to do anything except breath loudly (and everyone looks round to see where the train has broken down). At moderate to high intensity, which is a good workout range, you are sweating and breathing hard, and can get out a few words at a time, but not a complete sentence. If you can hold a conversation, you need to increase your intensity.

An important measure of fitness is how quickly your heart rate returns to normal after a sprint. If it's close to normal within a minute, then you are in good shape.