Immunodepression and Exertion

Posted on 11/07/2019

Feature Image by: Alexis Berg

Struggling with the Flu? This one’s for you!

Feeling physically exhausted after a long or hard training session/block isn’t uncommon, but did you know that your immune system takes a pretty big knock during these sessions too. Reduced immune function following exercise has been shown to increase the likelihood of contracting some form of sickness especially in the form of upper respiratory tract infections (URTI’s). This is a less than ideal situation for athletes who need to maintain some consistency in training or in leading up to an event. Not to mention a catastrophe for their family and friends – sick runners are a pain in the butt.

Immunodepression post such hard efforts in training and race day is a well-researched and accepted notion and creates an ‘open door’ for infections and sickness. Your body’s immune response is a complicated coordination between physical elements, cell types, hormones and interactive modulators, which all need to work together to ensure you stay off the couch and in your running shoes. Although intense exercise puts strain on this system, it doesn’t destroy the cells and hormones responsible for keeping you healthy, rather it reshuffles things around a bit, moving cells to other areas in the body,  while it resets. And while the body is returning to a normal state, this is when the sniffles can make their move. This is not the same however for regular low-intensity exercise, which has been shown to have the inverse effect and rather than make you prone to URTI’s, it protects you from them.

Banter with Banting

So now we understand why we keep getting the pesky chest infection after a big effort, but what can we do to try to avoid it both during and after the session? This is where the Banters can stop reading – CARBS. Yes. Carbohydrates have been shown to help maintain the function of the immune cells responsible for keeping that infection at bay. Immune cells have extremely fast metabolic rates and glucose is the primary fuel choice for these cells, so it makes sense that in order for them to function properly they need their primary fuel choice. On top of this, low blood glucose levels that may occur during fasted, prolonged or intense efforts also results in raised levels of stress hormones; cortisol, epinephrine and growth hormone, all of which have been shown to have immunosuppressive effects. So ensuring that you keep sufficient and stable blood glucose levels will help to maintain immune cell function, decrease stress and improve overall immunity.

Carbohydrate Recommendations: During Exercise

So what does this mean? It means that the current recommendation is to consume 30-60g of carbohydrates every hour for high-intensity exercise or exercise or exercise that lasts more than 90 minutes. This will help the functioning of your immune cells post exercise (and no surprise, as a bonus it also helps keep your performing at your peak).

But what may you be thinking is 30-60 grams of carbohydrates?

30 grams to get up and go:

  • 1,5 Sachets of Gu Energy Gels
  • 1 Science in Sport Isotonic Energy Gel
  • 2 small, salty, boiled potatoes (for those ultra-distance trail runners or triathletes craving something salty)
  • 1 medium banana
  • 2 Medjool dates
  • Energy bars (most will be around 30-60g, just look on the back label at the carbohydrates section to check it is packing enough punch)

60 grams and going for gold (or really long):

  • 2 Science in Sport Isotonic Energy Gel
  • 2 x Onigiri or Rice Balls (Thanks Jason Coop and Scott Jurek for this one)
  • 1 serving of GU Roctane Energy Drink
  • 1 handful of jelly babies
  • 3 dates stuffed with peanut butter
  • 2 slices of bread with peanut butter and honey/jam

Carbohydrate Recommendation: Post Exercise

The current recommendation is to consume between 1,2 grams per kilogram of body weight in carbohydrates and 10-20g of protein after strenuous exercise for muscle protein synthesis, glycogen restoration and training adaptations to take place. What is important to note is that carbohydrate consumption directly after exercise has also been shown to be beneficial in restoring immune function, especially so when the time between bouts is short.

So yes, carbohydrates are important for ensuring your immune system is able to keep the chest infections and general sniffles at bay. In saying this, there are many factors that contribute to having a healthy immune system, not only what you consume during or after exercise. Adequate sleep, a nutritious and sufficient diet to support proper bodily functions and provide antioxidants to reduce stress hormones and controlling environmental and phycological stressors are all also important things to consider when it comes to your health.

Want to read up a little more? Pop us an email and we will share with you our resources. All the information from above is obtained from sports and medical journals and is up to date at the time it was posted. We at RUN are all about community and also love hearing from you, so comment below with any of your experiences with running and getting sick.

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