Articles

Some technical stuff I've written about over the years...


Central Governor Controlling Fatigue in Endurance Sport

PART 1

One of my favorite Ironman moments... Sian Welch and Wingnut 'sprint crawling' for the line at Ironman Hawaii.

A great example of the Central Governor in use. These girls would have been in a World of physiological distress over the course of the run putting an immense about of strain on their heart, but being the Elite athletes that they are they manage to ignore their CG telling them to stop... that is until they see the finish line and they can't keep fooling the CG anymore. It knows they have reached their destination so it's 'System Shut Down' the CG is actually forcing them to stop by preventing their legs from working anymore. Although it is often stated that running out of fuel is the problem this is only a small part of what is happening... you can always at least walk using your fat supplies.

So if you're doing an IM this season... you haven't gone hard enough until you CG forces you to crawl ;-)... IM isn't necessarily good for you... you know?

The 2 main reasons which cause people to be reduced to a walk / crawl in an Ironman are going too hard on the bike and eating too much (not too little).

1. Go easy on the bike... the first 40K should feel 'Too Easy'. Most people you see walking on the marathon are doing so because they pushed too hard on the bike, not because they are bad runners. The only time you should push on the bike is when you hit a rough patch, when you don't feel too good, this is normal over a 180K bike ride so expect it to happen a few times... When it does focus on just pushing to maintain your pace (not increase it) and the bad feeling normally goes in 5-10 minutes. As soon as you go over your red line (anaerobic) your cardiovascular system will struggle to return to an aerobic state and your IM race will be slower than you expected.
2. Don't eat too much. Despite what many people think most nutrition problems in IM are caused by eating too much... in particular eating too many solids. During racing the stomach shuts down, the blood needs to go to other places... Fluids and sugars it can cope with in the right amount but whack a few power bars, peanut butter sandwiches or whatever down there and you soon clog your digestive system up. As a result your stomach stops absorbing the sugars and a system shut down and slow walk home is on the cards... So limit the solids you take in (1-2 bars should do) and when you do, take them in bite size chunks.

PART 2

I want to write a bit about the ability to be able to 'Push Yourself'... a lot of athletes complain that they are unable to push themselves... to make themselves 'hurt', most of them would be right in thinking this. Being able to really hurt yourself is a talent and a skill in itself in the same way that good swimming technique, good race tactics and good aerobic capacity is.

I tend to go with the Central Governor Model (CG) as proposed by Tim Noakes et al and a growing number of individuals interested in athletic performance. It is used as a model to explain exercise limitation being governed by the Brain rather than the traditional model of lactic acid accumulation which states that we slow down when our muscles stop being able to clear more lactic acid than they are producing.
The CG is in the lower centres of the brain... it is constantly monitoring the bodies homeostasis basically to protect the heart... amongst other things it is monitoring oxygenation levels within the organs of the body... as soon as it detects these to be at damaging levels then it will force the body (YOU!) to slow down.
So when you are racing (or training) this is the point when you start thinking to yourself... "ooo this is getting pretty painful / difficult / I'm hurting!!" and you either stop getting any faster or you slow down or even stop altogether... according to your CG continuing in this 'crazy' manner could cause damage to your precious organs such as your heart.

There are two ways to overcome the central governor.

1. Become as efficient as you can at moving from A to B with the biggest aerobic engine you can get, so that the speed which causes a decrease in oxygenation and hence the CG kicking in is well 'dam fast'!
2. When the CG does kick in well... ignore it... using the higher centres of our brain... the bit's of the brain that we think with... the ability to push yourself.

I've explained in past Tricoach blogs about developing your technique and aerobic system... we get so used to performing the movement that even when moving at relatively high velocities it does not trigger our CG. For most of us out there consistent aerobic training will give us the greatest gains long term.

How can we ignore the CG? Unfortunately like all attributes it is to an extent a genetically gifted skill. One talent that makes Elite athletes as fast as they are is to keep ignoring their CG. Go and watch a World Class bike TT where the riders HAVE to go as fast as they can... (no tactics in a TT) many of them collapse after they cross the line and need to be put on an Oxygen cylinder. They have actually caused damage to their body as they managed to switch off their CG... Elite level sport isn't good for you :-).
Compare that to your average Triathlon with people strolling across the line and standing around having a good chin wag... Their CG would've kicked in very early and with little resistance.
There are things we can do to enable us to push ourselves better.

1. Racing! Nothing can duplicate the environment of racing... weather, course, competitors, spectators, having your mom watching, taking 3 poos before the start. This environment often means we can push ourselves more. It usually takes a few races though. We often find it difficult to push ourselves in the first race of the season because the CG just doesn't know what's hit it. As we get used to the pain of racing we find we can tolerate things better.
2. Anaerobic / Interval Training. Yes the hard training amongst other things allows us to learn how to ignore all those painful signals. However we need to be careful with this... most age group athletes will be better off working on their efficiency and aerobic ability. Also if you do TOO much Anaerobic Training or Racing then it can cause our CG to kick in even earlier... The CG doesn't like us smashing ourselves too often and it will become hypersensitive to any decrease in oxygenation. This is seen time and time again in those athletes who RACE or go hard out in all there training sessions. When it comes to real racing when they need to push themselves properly they just can't. For most 3-8 weeks of hard training is sufficient... per year or per 6 months depending on the athlete.
3. When you do your Interval Training keep it short and sharp and only 1-2 times per week. It's no use doing if you are tired as you won't be mentally fresh enough to ignore the CG. Personally I find good interval training very hard to do... it wears me out meaning that the chance of getting a 20+ hour training week in is going to be tough and also endangers my chances of being able to push myself when needed in a race. Interval training has to be administered at the right time in the right dose.
4. Reduce stress and keep your mind fresh... a tired mind is good for nothing and will give in quickly to your CG. Meditation is good for some... but just getting some good kip and not trying to do too much in life is best for most.
5. Mental strategies... this is too big a topic to do here but it probably the best method of coping with your CG and going faster. A good thing to remember is that the pain you are experiencing telling you to slow down is just a 'sensation'... it won't cause you any harm. Tell the pain that "Right now you've got a job to do and there's no way you're slowing down!" Distraction tactics are also good when you think of something else. I like to "Give myself to the pain... embrace it... ACCEPT that it is totally normal and more often than not I can keep going, keep relaxed, keep getting faster, I become numb to the pain though I know it's there.
6. Proponents of the CG model propose that even if you feel you can't go faster because of leg pain it is actually your CG shutting down your legs to stop you putting strain on the heart... there is no great damage to your legs really and your CG doesn't really care about your legs... they are expendable but your heart isn't.
7. NO EXCUSES! Everyone will go into a race with certain insecurities... the niggling injury, training sessions missed, being kept awake all night by the 'Jungalist Massive Crew' partying next door... etc, etc. 'LIFE' tends to get in the way, nothing can be perfect, just accept this is the case rather than stressing about it. When it comes to the race your CG will latch on to any of these excuses you have... "Well I could push it on the run now but I haven't been able to run much in the last few weeks so I won't it's too hard"... CG has won convincing you that it's not worth pushing it... When it comes to the race get rid of all those excuses... we all have excuses but people who ignore them the most do the best.

Now during a race we want to avoid pissing the CG off too much. We want to get through the majority of the race without setting it off. It will send off a few preliminary warning signals during the swim and bike... we can ignore these and keep pushing... just not too fast as we'll blow. However there's nothing that will set off your CG more than going anaerobic during a race... even a sprint race. If you try to smash the swim for example you will suffer in the rest of the race... the decrease in oxygenation will be detected by the CG and cause you to slow down on the bike until you recover... even more reason to draft in the swim :-).
Generally it's only in the run for Oly and Sprint Distance Tri's when you the CG will start working and you have to start battling it and keep pushing. For Half and Full IM distances it should only be in the last half of the run.
So in your next few races... use your concious brain to control the lower centres and just squeeze that last bit of performance out of you... if you can still walk you haven't gone hard enough ;-). Just like me at IMNZ09...