Running on empty - low glycogen improves endurance

[PPWTF]

 

Came across this on Bike Radar

 

http://www.bikeradar.com/fitness/article/training-running-on-empty-18071

 

"If you think glycogen is the stored form of carbohydrate we

use to produce the energy required for cycling, you would be correct. However,

glycogen does a lot more than just that. Scientists have discovered a

crucial second function that directly affects endurance performance and could revolutionize the way we endurance train."

 

?There are essentially three things that limit endurance

performance: VO2 max, lactate threshold and cycling economy,? says Dr Keith

Baar of Dundee University, an expert on AMPK.

?Improved glycogen signaling can boost two out of the three: VO2

max and lactate threshold.?

Makes for interesting reading.........

 

 

 

PPWTF2008-09-29 12:27:32

[FanieFiets]

 

interesting, arme pieman!

FanieFiets2008-09-30 01:11:13

[123qwer]

I saw that aswell 

[widget]

I think he has been "smoking his socks".!

 

Gos against all conventional wisdom.

[Hog_]

Please don't tell the TdF riders!

 

 

 

[PPWTF]

 

 

 

?Improved glycogen signalling can boost two out of the three: VO2 max and lactate threshold.?

 

This

would be interesting but not practically useful were it not for one

crucial point, the scientists showed our signalling function can be

improved by training when glycogen stores are low, which is a radical

break from conventional wisdom.

 

How low-level glycogen training affects performance

Generally,

athletes of all levels are told to have a carbohydrate-rich meal two to

three hours before any training occurs, ensuring their glycogen levels

are fully topped up.

 

But these studies suggest that purposefully

manipulating your glycogen level so that it?s around one third depleted

results in improved signalling, hence greater muscular mitochondrial

mass and better endurance performance.

 

?The exact mechanism is still being investigated, but this could work in a number of ways,? says Baar.

 

?For

example, training on low glycogen puts the body under extra stress,

meaning it produces more adrenaline. Therefore the body adapts to

dampen the body?s response to adrenaline, which in turn helps to

increase the lactate threshold?.

 

How to train your signal pathways

Dr

Baar?s fellow boffins at the University of Birmingham have even created

a training session specifically designed to increase the signalling

function of glycogen. The idea is to purposefully lower your glycogen

until it?s depleted to the right level, then to do some high-intensity

training in that state.

 

Have a low-carbohydrate meal prior to

the session and then beginning the workout with 45-60 minutes of

low-intensity, steady cycling at around 70% of your VO2 max (a level

where you can still breathe through your nose, with your mouth shut).

After your glycogen is sufficiently depleted, switch to intervals of five minutes? hard exercise with a minute of rest in between.

This will train your signalling pathways to maximum effect.

 

?We

know from studies that training at high intensity activates AMPK at a

greater rate, plus we know this effect is improved when training at

lower glycogen levels, so this session gives twice the activation,?

Baar explains.

 

Short-term limitations versus long-term benefits

Before

embarking on glycogen manipulation training, it?s important to

recognise its limitations. For example, if you?re a track rider and

don?t race for longer than an hour, this type of training is going to

be largely ineffective on your short-term performance.

 

The

reason for this is that improving your glycogen signalling increases

your energy efficiency at slower speeds, when you are undergoing aerobic

respiration and want as much fat-burning as possible. Racing shorter

distances for an hour or less requires a faster speed, meaning that

your body has to burn carbohydrate no matter what, so glycogen

signalling is largely irrelevant.

 

But for longer distance

events, particularly stage rides where you have to pedal day after day,

this type of training can bring definite benefits.

 

Only pure endurance will get the full benefit

You

also need to be careful about when and how often you perform this kind

of training. Unlike running, which requires only pure endurance,

cycling also requires a degree of explosive muscle strength to power

the pedals.

 

Crucially, glycogen manipulation will only work for

pure endurance training. So there?s no point going into a weights

session in a glycogen-depleted state because you?ll simply fail to get

the full benefit from the workout.

 

At this stage it's probably only applicable to real elite level performance - the reason it caught my eye is;

1. That science is routinely bashing many of the old 'accepted' wisdoms of endurance training over the head
2. No sooner is quality academic research complete than this info is available in the public domain

Factor 1 & 2 together and never has there been a better time to be an up and coming athlete

 

PPWTF2008-09-30 03:26:03

[jabbathemutt007]

 

 

?For

example' date=' training on low glycogen puts the body under extra stress,

meaning it produces more adrenaline. Therefore the body adapts to

dampen the body?s response to adrenaline, which in turn helps to

increase the lactate threshold?.

[/quote']

 

The problem is under heavy load (intervals) on low glycogen levels your body tends to cannibalize muscle tissue for energy which is both counter-productive and increases recovery time.