We now live in a time where running a marathon just isn't enough and people are constantly striving for more. With more people participating in extreme endurance races than ever before, it poses the question: can too much exercise be bad for you?

How much exercise is too much?

Most of the population lives a sedentary lifestyle with 4/5 of adults in the UK working a desk job and sitting staring at a screen all day. For these people, there are multiple health risks associated with being under-active and not exercising enough. Someone who sits at a desk all day and then hits the gym for an hour or two each evening will not suffer any negative side effects from exercise.

However, there are now increasing numbers of people deciding to challenge themselves and shake up the monotony of everyday life by taking on extreme endurance challenges. There are now more ultra challenges available across the globe than ever before, with races like the Arch To Arc triathlon and Badwater Ultramarathon testing people mentally, emotionally, physically, and spiritually. These events are not only taxing due to their length, but often the elevation demands and terrain are extreme too. 

Not only do these events put the body under immense strain, the endless hours of training required to even get to the start line can have effects on the body too. A study published by James O'Keefe and Carl Lavie found that while people who exercise regularly do have lower rates of disability and a longer life expectancy, there is an upper limit to how much exercise is good for you before it starts having negative effects. O'Keefe and Lavie defined excessive exercise as running more than 5 hours per week. 

To many, this will sound incredibly low, and there are plenty of athletes both professional and amateur who train 5 or even 10 times as much as this. Especially if you are training for something like an Ironman triathlon, you will probably be putting in well over 20 hours of training a week. But does this really mean you are reversing the positive effects of exercise and ending up as unhealthy as a couch potato? Thankfully the answer to that question is a resounding 'no'.

Dr Andrew Murray of the University of Edinburgh reassures us that while there is indeed an upper limit to the amount of running you should do, it would take a lot to make you end up as unhealthy as someone who does not exercise enough. 

What are the symptoms of over exercising?

The symptoms of over exercising differ from person to person and if you feel you are suffering from one symptom, it is not necessarily an indication that you are over training. However, a combination of a few of the following symptoms of over exercising may denote a need to slow it down and take a complete rest day:

• Muscles aching for more than 3 consecutive days
• Not being able to sleep despite feeling tired
• Backwards progress in your training
• Reduced appetite and/or rapid weight loss
• Irregular heartbeat

Effects of exercising too much

There are several negative health implications that have been found to be caused by over exercising. A build up of calcium in the walls of the heart can lead to heart disease while exercise-induced asthma could be something you end up having to deal with if you run excessively. 

However, it is very important to note that the vast majority of people do not need to worry about these effects of exercising too much. Most people do not exercise enough and the health risks associated with a sedentary lifestyle are far worse than those you might suffer from if you exercise too much.

In order to start suffering from over exercising, you would need to be training for several hours a day every single day, which most people simply can't do because they are at work for most of the day. So, if you are sat at a desk for 8 hours a day, you do not need to worry about the effects of exercising too much, and would instead probably benefit from exercising more.