How different types of athletes utilise energy

How different types of athletes utilise energy

As athletes, we all utilise energy differently. Your average man on the street running a marathon; will consume energy differently from the likes of a professional Kenyan runner. On this episode of 32Gi Sports Nutrition we look at the different types of athletes; and how their bodies tend to utilise energy.



Welcome to this edition of 32Gi Sports Nutrition. I’m David Katz, Mr. Active joined by Mark Wolff. In a previous podcast we talked about the energy system and how it functions.

Today we looking at athletes in specific and how they utilise those stores from the energy system. Mark looking at an elite or high performance athlete in particular they’re going to fuel themselves differently from your average man on the street.

So how do different types of athletes bodies fuel?

MW: Sometimes yes and sometimes no Dave. I think first of all we looking at elite or high performance athletes generally we have in our minds that they’re going at a very, very high intensity. However there are some elite athletes that because of their duration of the even actually still go at a more controlled pace.

Let’s have a look at the high intensity performing athlete. So somebody is doing a shorter distance event and going at a much higher intensity over a shorter distance. In other words, they are going probably above threshold and they getting very little oxygen into their systems.

So in a previous podcast we discussed the different storage tanks, well the different fuel tanks, and that being glycogen and fat. We mentioned that glycogen is generally the main fuel tank when there’s oxygen deprivation in the body. In other words, there’s not enough oxygen coming into the system; glycogen is definitely going to be your major fuel tank.

So what actually happens is if an athlete is performing at a very high intensity, he is getting very little oxygen into the system. The only tank that’s going to be fuelling his body and ultimately creating ATP to fire those muscles is the glycogen tank.

How a high intensity athlete needs to fuel

So what can he do, he needs to be able to try and spare as much glycogen as possible. So from a fuelling perspective that athlete will have to take in a quick releasing carbohydrate in order to be able to spare the glycogen.

We can spare glycogen probably around 30%. I’m using it as an average number. I mean it could be less, it could be more. There’s a lot of variant factors but that’s generally the only way.

So you know for athletes that are going at a much higher intensity and definitely predominantly utilising their glycogen store then we looking at a higher and quicker carbohydrate feed.

DK: Mark looking at something like oxygen deprivation because when you competing at that high speed you going above your threshold, you are starting to drop your oxygen reserves. Is there a way to replace that from a nutritional point of view?

How to curb oxygen deprivation when racing

MW: There’s nothing really we can do about oxygen. The only thing you can do is to lower your pace. Is to slow your pace down and get those airways open. People sometimes say to me, “How do I know if I’m burning fat or glycogen?”

A simple rule of thumb is if you are puffing and panting and you can’t get any air in you are definitely chewing up your glycogen stores. So there’s no doubt that you need to feed that appropriately. On the other hand you know when your glycogen stores are depleted, your brain will naturally slow your body down.

We call that bonking that’s the feeling of glycogen stores completely emptied. The bodies going to transition to a different fuel tank. That fuel tank it’s a small tank compared to a glycogen tank.

It’s a much larger tank but it is in a way a reserve tank. It’s going to slow the body down; it’s going to allow a process of oxygen coming into the body and then getting that fat broken down. Then getting it converted into glucose and utilising that fuel.

So very, very painful process. Athletes go through emotional turmoil when they do hit the wall. The only way to really get better and better at this is to become more of a fat efficient athlete. That transition between glycogen and fat is probably, let’s say the transition is more transparent than severely impactful.

DK: Now Mark a little bit earlier on you mentioned something about the controlled paced athletes as opposed to your high performance athlete. Here we are you looking at what probably anything over a marathon; or Comrades, Ironman athletes, these are those kind of athletes.

What we all can learn from endurance athletes

MW: I think it’s quite interesting. I mean I think first of all pace is also about perception and intensity is about perception. If we have look at a Kenyan marathon runner you’ll never see these guys taking gels on route. I mean these guys, yes they hydrate themselves and that, but they not getting really anything into the system.

They are running at a pace, I mean even though it’s around 20 kilometres an hour for some of these athletes, that pace can be sometimes controlled sometimes not controlled. They’re basically just trying to rely on their glycogen stores to get to the finish line.

That’s why after a two hour marathon, or two and a quarter hours depending on the time. Generally these guys are finished so they not going to carry on for much longer.

But now – let’s say the distance of that even increases and these elite athletes now have to go and run an ultra. So 56 or even if you looking at a Comrades Marathon distance which is an 89 kilometre run.

Suddenly now you realise there is no choice but to run or to perform at a controlled pace. Some of the athletes that I’ve worked quite closely with it’s very, very interesting to see a controlled pace they are primarily burning a larger amount of fat than they are glycogen.

We did some testing on some elite athletes in South Africa. What we noticed was well these were elite athletes; when they were running at 4min/km interestingly enough their fat oxidation rates were quite high. They could go on water for about three to four hours quite easily. But as their pace increased around the 3:40 mark, there they required a much higher feed.

Pace will determine how you need to fuel

So controlled paced athletes you’ll find them more over the distance events or also over this you’ll look at social athletes. I often say the difference between a social athlete or an elite athlete; is that is sort of that mental barrier to push yourself into what I call the dark zone or to that dark side. Where you really are putting yourself into a world of pain and you holding it for a very long period of time.

It’s a very emotional place to be. There’s a lot of people that are very afraid of doing it and they controlling their pace all the time. Based on the kind of pace that you performing at, that will ultimately determine the type of nutrition that you should be taking in.

If you are going at a very controlled pace there is absolutely no reason to spike your blood sugar significantly. That’s going to lead to what I call the roller coaster ride. Up and down, feel good feel bad and ultimately it can also lead to GI distress. Because there’s a glucose overload in the system.

So you really need to try and differentiate between these two major types of athlete, one performing at a very high intensity and one performing at a more controlled pace. Then obviously you get what we call a combination athlete.

Somebody that’s maybe starting a race out at a very controlled pace but then they going to use the other combination of upping the intensity towards the finish. In other words, then going and performing at a much higher intensity.

Maybe the feed will vary to support those two different efforts but it really depends on the type of athlete you are. That will ultimately determine it, pace will determine feed.

DK: Mark just going back to something you said earlier on. Looking at glycogen depletion, if you’re a Kenyan and you running around 3min/km and finishing a marathon just over two hours. Or if you running at 6min/km and you finishing it over four hours, who is going to deplete their glycogen sources first?

How glycogen depletion varies

MW: I think again it depends on what that particular athlete is going through at a pace point of view and what’s happening to his body at that point in time. So if a Kenyan runner is running at around 3min/km, he might be oxidising quite a large amount of fat along with the glycogen, of course at that particular intensity.

When he ups his speed even more and these guys sometimes do go under 3min/km in the last couple of kilometres of that event. Then predominantly he might be tapping into his glycogen stores fully. Fat just doesn’t become available at all.

But depending on the percentage of the fat utilised he will be sparing a certain amount of glycogen. So that’s why a Kenyan runner might not fall flat at two hours he might fall flat a two hours and 15 minutes. It all depends on how controlled that pace is. If you think of a marathon it’s really a war of attrition.

These guys are all running at a fast pace but nutrition plays a very critical role or actually pacing yourself plays a very critical role. If I look at let’s say more of a social athlete to somebody that’s running the same distance as a Kenyan athlete but they running it in four hours as you mentioned. It’s very possible that, that four hours for them could also be a high intensity or it might be a very controlled pace.

In other words they just want to get to the finish line. Those are the two types of athletes, or there could be a combination athlete in there. But then ultimately they would have to feed because running for four hours over a longer period of time, you will need to focus more on the nutrition.

Because as the distance grows and I’m not talking about distance as in distance of course, but as the time on the legs grows. The amount of time that the body is working for grows and extends, nutrition becomes more and more critical over that period of time. Because those fuel tanks need to be catered for. Those fuel tanks would be catered for depending on the pace that you performing at.

DK: Well Mark another fascinating podcast and if you want to hear some of our previous podcasts or to find out more about the products go to also if you want to get questions into Mark about nutrition go look at coach, you can ask the coach on the website. Thank you for joining us on this episode of 32Gi Sports Nutrition from myself David Katz, Mr. Active and Mark Wolff we’ll catch up with you next time.