Fast and slow releasing energy
There are several equestrian disciplines and each discipline requires different skills from the horse and rider. For dressage you need discipline, patience and stamina. On race courses you see super sprinters who need explosive energy.
We often talk about fast and slow releasing energy, but what exactly does that mean?
Your horse has 3 different types of muscles, type 1, 2a and 2b.
Type 1 muscles have the following characteristics:
- They contract slowly
- They need a lot of oxygen
- They can work for a long time
- They burn especially fatty acids
- They are surrounded by fat tissue which enables the transport of fat as the fuel to the muscle
These muscles are well suited for work that needs stamina, like endurance.
Type 2b muscles have very different characteristics:
- They can contract very quickly
- They work with or without oxygen
- They burn glucose (sugar)
- They can store spare ‘packets’ of glucose in the shape of glycogen
These muscles are very suitable for work that requires speed, like racing.
Type 2a muscles have a little of both the above characteristics.
A horse uses different energy sources as fuel for work. The two main ones are sugar/carbohydrates and oils/fat.
Sugar/carbohydrates have the following characteristics:
- Carbohydrates consist of many sugar molecules, connected to each other after extracting their moisture content
- Sugars are single molecules, which are easy to break down
- As a result, sugars are quickly available for the muscles after intake
- Burning glucose produces, besides energy, waste products (lactic acid), which have to be neutralised (see article 14 about Vitamin E and selenium)
Oils/Fat have the following characteristics:
- Oils and fat are broken down into fatty acids
- It is more difficult to breakdown oils/fat than sugars
- As a result, it takes longer for the energy to be available
- Fatty acids provide three times more energy than sugars
- Burning fatty acids does not produce any waste products, so it is a ‘clean’ source of energy
What does this mean in practice?
When you compare the above characteristics it is obvious that the best fuel for slow contracting muscles is oil/fat.
For endurance, where stamina is needed, you need a feed which contains relatively a lot of oils and/or fat. This provides a lot of energy and your horse can work for long periods. If you feed more than your horse needs for it’s work, then your horse will quickly put on weight.
The best fuel for quick contracting muscles is sugar/carbohydrates. So, for explosive sports like show jumping or racing, feed with a relative high sugar/carbohydrates content is suitable.
Don’t give your horse a feed with a high sugar/carbohydrates content without any reason. It works well when your horse is in full work, but an overdose of sugar can upset the body and even cause glucose-intolerance and/or insulin-resistance.