If you have strong muscles and you use them well, then you will fun fast and jump and throw far. If you strengthen your muscles, then you can run faster and jump and throw further still. But working muscles tire very quickly. In order to keep going they must renew their energy. They need oxygen from air inside your lungs to pass through the lung walls into the blood and be pumped by the heart to the working muscles. Then the oxygen must leave the blood and gets into tiny “energy factories” within the muscles, where oxygen is used to burn food and release energy.
So, for an endurance runner, the efficiency of their oxygen transport system is even more important than muscle strength. This efficiency depends on many things like how easily oxygen can pass through the lung membranes, the oxygen carrying power of the blood, the pumping power of the heart muscles, and the number and size of the “energy factories”. Fortunately there is a way to improve all of these. It is called “training”
Measuring Oxygen Transport Efficiency
In 1982 two Canadian scientists published a simple way of measuring how fast an athlete can transport oxygen. We call it “the Bleep Test”. The test requires a “track” 20m long with a line at each end. Each runner stands behind a line at one end and, on the start bleep, runs up their lane, to put a toe on, or over, the far line. Then turns to run back on the next bleep, and so on.
At first the bleeps are very slow. (9 seconds to cover 20m. Fast walking pace.) If you can just manage this, your fitness is “level 1”
After a minute the bleeps become slightly faster for level 2. After another minute they get a little faster still for level 3.
You go on and on, without a rest. The bleeps get faster at each level till you can no longer keep up. You can’t transport oxygen fast enough. Your fitness level is the fastest one that you could manage. Most of you will get up to level 3, unless you are a super vet, or have a health problem. The super fit will get to level 12 or more.