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Is there a point when exercise becomes ‘unhealthy’?

Kate Freeman

What?! How can you even ask that question? Aren’t you a healthy lifestyle ambassador?

Yes, I am! Well, I’d like to think that I am. And yes, it’s true. There is a point where exercise actually becomes detrimental to your health.

Before you get all cross at me and give up your daily gym routine hear me out.

I’ve spent quite a bit of time lately engrossed in some scientific literature whilst researching the link between exercise and immunity for a client. And what I found was very interesting. Check out Episode Six of The Daily Dollop below for what I found!

For more of The Daily Dollop click here!

Moderate, regular exercise is good for you

Exercise, defined as planned activity to move your body and increase your heart-rate, if done regularly and at a moderate level, boosts your immune system.

See, it’s not all bad news, put those runners back on!

Exercise is good for you for a number of reasons:

  • Exercise reduces inflammation in the body, which is thought to be a pre-curser of disease.
  • Exercise boosts the innate immune system, specifically the white blood cells that fight off infection.
  • Exercise improves physical strength and fitness.
  • Exercise improves your blood sugar regulation and consequently decreases your risk of insulin resistance and type 2 diabetes.
  • Exercise boosts your metabolism and helps strengthen your bones.

It’s pretty awesome!

The key to these benefits: You’ve got to do it regularly, so most days of the week and ata moderate level.

There’s that word moderation again. What does that actually mean? By definition, the word moderation means to not doing anything to excess or extreme. I’d say that’s a pretty good word to describe the effect that different types of exercise have on our ability to fight disease.

Too much exercise may be unhealthy

A moderate amount of exercise is good for us, but taking it to an extreme level or exercising to excess actually starts to do the opposite and make us more susceptible to catching something nasty!

Excessive levels of exercise, like running a marathon for example, has been shown to decrease immunity and increase susceptibility to upper-respiratory tract infections.

Population research suggests that endurance athletes (runners, cyclists, rowers) are at an increased risk of catching an upper-respiratory tract infection during periods of heavy training and in the 1-2 weeks after a race or competition.

Research shows us in more detail that after a very heavy strenuous or prolonged exercise session that there is a suppression of your immune system in the hours following, making you more susceptible to viruses and bacteria.

Have you ever run a half-marathon/marathon and then come down with cold or the flu? I have, and it wasn’t pretty. Another time when I first started CrossFit, I was training very intensely from what I was used too. My kids were also in day care at the time. This was a recipe for disaster.

Day care bugs + run down Kate from excessive training = worst flu of my life where I may have fractured a rib from coughing so much! Yep. I’m hard core.

Isn’t it amazing how everything comes back to balance? It’s the goldilocks principle. Not too little, not too much, just right.

If you’re participating in the Canberra Running Festival this weekend, never fear. Your nutrition can actually help decrease the immune suppression that occurs with an exhaustive bout of exercise. Here are a few tips:

  1. Meet your energy needs. You must make sure you’re eating enough. If you’re in an energy deficit, whilst training for a marathon, you’ll have a much higher chance of getting sick. Your energy intake must meet your energy output. If you’re not sure how to do that, you need to seek help.
  1. Adequate carbohydrate intake. Many people are confused about carbohydrates because, let’s be honest, there are soooo many different opinions about it. The reason it’s confusing is because everyone’s carbohydrate needs are different. You’ve got to find the right intake for you. This often takes professional help plus trial and error. You also need to adjust your nutrition if your training levels significantly change. Research shows that adequate consumption of carbohydrate during or after an endurance event decreases the drop in immunity that occurs after a heavy session. So make sure you grab yourself a nice big meal, once the race is over!
  1. Consume adequate vegetables. A by-product of your body burning food for energy (metabolism) is the production of oxygen reactive species, otherwise known as free radicals. No, they’re not an 80s punk band, they’re damaging chemicals that wreak havoc on your cells and DNA. Consuming a diet rich in fruit and vegetables ensures you’re consuming enough anti-oxidants. These chemicals, found in plants, neutralise free-radicals. An adequate intake of these nutritious plant foods can help with recovery, keeping those nasty free radicals at bay. Also nutrients like vitamin C and A are shown to important in keeping your immune system healthy!

Further reading:

Nutrition for endurance runners – The Healthy Eating Hub – By Kate Freeman


Kate Freeman

Kate Freeman is a Registered Nutritionist and the founder and managing director of The Healthy Eating Hub. Kate’s healthy eating philosophy is all about whole, fresh foods, being realistic about life and creating long term healthy eating habits. She doesn’t believe in detoxes, fad diets or quick fixes. Once you’ve finished working with Kate, you’ll be empowered to feed yourself well for the rest of you life! More about the Author

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