Beginners Guide to Power Zones 2 - What are Zones?

Some fundament rules of cycling will be familiar to all riders of whatever ability:

• Not all efforts feel the same.
  

An all out sprint feels different from a 10 mile time trial which in turn feels different from riding a road race with lots of short hills which in turn feels different to century gran fondo with multiple epic climbs which in turn feels different to an ultra endurance event lasting several days.

• Every effort has its limit
  

Efforts may vary but one thing is consistent. The first few seconds, minutes or even hours (depending on duration) may not feel that hard. But if you keep pushing hard at that pace then at some point something will give and your legs will stop working. You may not come to a dead halt but you will experience a sharp drop in your performance and it will take a while before you feel ready to pick up the gauntlet and try again.

• The harder the effort the quicker you hit the limit
  

If you go very quickly than you will hit your limit very quickly, after just a few seconds. If you go very slow the limit may not come for days. In between the margins can be small. You can attack a small hill confident that you can reach the top only to crack when you turn a corner and find that it is not the summit but the half way point.

It is as if, like a car, your body has a number of “gears”. The higher the gear then the faster you go, but at the cost of drastically reducing the time for which you can maintain your speed.

The reason for this occurring is that the human body has adapted to produce energy in a number of different ways, each suited to deal with a different survival challenge. At one extreme is the requirement to instantly move very quickly to catch prey or avoid a predator, at the other is the need to endure long months of winter with famine knocking at the door. In between is the mix of physical activities which our hunter-gatherer ancestors had to perform every day.

Taking the car analogy a bit further helps with understanding this. Your body is a complex hybrid, with multiple types of engine. Your sprint is like an ethanol fuelled dragster, your ultra pace like a diesel truck with a specially extended fuel tank. Filling the middle is a petrol fuelled car whose owner has fitted a turbo charger which quickly adds a lot more power for overtaking. Unfortunately they did not alter anything else. So thrill of the turbo kicking in always risks being followed by the gargle of the fuel tank running dry or, worse, the engine exploding as the cooling system cannot cope.

Sports science uses the term “zone” to capture this concept and turn it into something that can be used in training.

Typically a zone will consist of two elements:

• A combination of effort at a given intensity for a duration. (so your “sprint” zone might be 10/10 intensity for 10 seconds).
  
• An underlying physiological “engine” that is especially important for this zone (so your “sprint” zone is linked to your “fast twitch” muscles)
  

The duration will be a range and not fixed in stone. They will vary between individuals and also for an individual over the course of a training period according to how they train. Indeed extending the time you can spend in a zone is often a training objective, though maybe at the cost of affecting other zones.

Zones provide a language to help athletes understand their current fitness level, to learn from/compare themselves with others and plan to improve in the areas most important to them.

As an example: say a racer has an issue with being dropped on hills. Just telling a coach this and expecting them to fix it hits the problem that hills can be very different from each other. The circumstances of racing can make these differences even larger. Zones can cut through this ambiguity and give this racer a means to pinpoint where they are weaker than their competition and suggest what they can do about it. Exactly how will become clearer once we have an actual example of zones to base discussion on.