DEVELOPING ENDURANCE, BURST SPEED AND SUSTAINABLE SPEED

LOW INTENSITY WORK > DEVELOPS ENDURANCE
Whether you have entered the 25km, 50km, 75km or 100km option, the Merida Bikes MTB Marathon Series are endurance events that will require good aerobic fitness. This is the ability of your heart and lungs to deliver oxygen efficiently to your muscles over a long period of time. Aerobic fitness is best improved by doing long continuous rides at a pace where you can talk comfortably. This "base training" forms a very important part of the MTB marathon programme regardless of your pre-existing fitness levels. The more efficient you are at working aerobically, the faster you will go for the same effort. There is a lot of research that supports this theory of "ride slower, go faster." The temptation to ride hard and fast for every ride should be avoided as the training benefits are less and there is a greater risk of injury and burnout through over-training and under recovery. These long steady distance rides can be social affairs. Try finishing the ride at a café or a different country pub each week for variety. These rides could also be done on a road bike and because of the dark winter nights they are often done at weekends.

HIGH INTENSITY WORK > DEVELOPS BURST SPEED
However if you only ever rode at an easy pace, your muscles would never learn how to work hard and fast. This is why training at higher intensities where our muscles are working anaerobically improves performance. Working anaerobically literally means that you are working so hard that the heart and lungs cannot supply enough oxygen to the muscles.
It causes fatigue very quickly due to the build up of lactic acid and so cannot be sustained for more than a few seconds or minutes and certainly not for 100km!! To imagine the concept of lactic acid building up in the muscles, think of pouring water slowly into a paper cup with a hole in the bottom that allows water to run out as fast as it runs in. This is what happens to lactic acid in the blood at low levels of exertion / aerobic training.

By pouring faster, there comes a rate at which the water goes in faster than it goes out and so the cup begins to fill. Training anaerobically for short periods of time makes the muscles able to tolerate this accumulation of lactic acid and makes them more efficient at clearing it away. It helps to develop the ability to pedal strongly on short sharp climbs and when bursts of speed are required. Interval training is a way to develop this. After a warm up period, these sessions involve a number of high intensity efforts followed immediately by a period of recovery.

The intensity effort / recovery cycle is repeated several times before you cool down. They are great for an "after work burn" taking just 30-60minutes but still providing a quality workout.
• Because high intensity training is powerful stuff, carrying a higher risk of injury, New MTBers should only attempt interval training when they have completed at least 6 weeks of base / endurance training. 1 high intensity session each week is then plenty.
• Once an adequate base of fitness has been restored, regular MTBers will find 1-2 high intensity sessions per week enough and should allow for plenty of rest.
• Experienced riders should do no more than 2 or occasionally 3 high intensity sessions per week.

MODERATE INTENSITY > DEVELOPS SUSTAINABLE SPEED
The point at which lactic acid first starts to accumulate in the muscles is called the anaerobic threshold. The anaerobic threshold varies hugely from person to person and is determined by your level of fitness.
Training for long periods of time close to the anaerobic threshold allows you to ride at a faster pace without the onset of fatigue. Determining your anaerobic threshold accurately requires scientific measurement and laboratory testing but as a general rule of thumb occurs if you can’t say "when-you-can-no-longer-say-eight-words" in one breath!! If all this sounds too technical, the anaerobic threshold is the level where the exertion you are putting in could be described as "hard but not flat out."
Initially you may only manage 10 minutes working at this moderately high intensity, but with training, you should try to work for up to 60 minutes at a time. Time trials are excellent ways of teaching the body to maintain such a consistent moderately hard effort, but longer interval sessions are also very beneficial. See interval training.