Beat It!

Published: 19th January 2007

Author: Words by Alan Milway Photo by Sutty

Understanding how your heart works - and how you can improve its function - is vital if you want to drop your lap times...

'It's all about heart.' We've all heard the phrase and on most occasions it's meant as drive to achieve. However, the most important aspect of any rider's preparation is how developed and trained their heart is.

When we perform any exercise that requires effort and is over a very short distance or burst our heart rate rises. Whether it is in response to previous exercise and is beating faster to rid the body of a build up of lactic acid or it is to sustain exercise at a hard effort, the heart is our most important muscle.

What is often forgotten is that the heart is actually a muscle and as such will benefit from training to improve and strengthen it. It is different to muscles in the arms and legs in its function, make up and that it does not fatigue as skeletal muscle does. But you need to understand that training improves its function and this will help us improve performance.

The heart is made up of two distinct sides and four chambers. The right side of the heart deals with blood that has been used and is low in oxygen. It is then pumped to the lungs to be re-oxygenated and when it returns to the left side of the heart it is then pumped around the body to the working muscles to supply required oxygen.

As exercise intensity and duration increases there is a greater demand for oxygen from the muscles. This demand is met by the heart beating faster and with bigger 'pumps'. Each pump sends more blood out so a combination of a greater pump (called stroke volume) and speed of the pumps (heart rate) means that there is a large rise in the amount of blood going around the body (cardiac output).

The level at which we can work, the duration at which we can sustain this and ultimately the level at which we can perform is limited by the heart. Training the heart is therefore vital and must form the backbone of any training plan. But what actually are we doing when we train the heart?

As we train the heart through exercising at increased heart rates (compared to normal day to day activities), we increase the amount of blood that is pumped by the heart in one pump - an increase in stroke volume. This means that for a given exercise level it will take a lower number of beats per minute to satisfy the demand for oxygenated blood. So heart rate for that exercise drops. Heart rates are therefore a very useful tool for us to understand how hard we are working.

As you are sitting reading this your body is in a relaxed state (hopefully!) and you are not doing anything strenuous. The demand on the heart is low and the number of beats per minute is quite low - this is known as resting heart rate. Typically a resting heart rate can vary from person to person from between 70 beats per minute down to as little as 29 beats per minute. Generally heart rate is a good guide to fitness levels. As fitness improves resting heart rate drops (for the most part due to a bigger stroke volume). Therefore it is very useful to monitor your resting heart rate over a period of time to see how it changes with training.

Resting heart rate is ideally taken first thing in the morning when relaxed in bed. If you take it once or twice a week you can see how it changes with training over time. It is also a very useful guide to your state of health and an increase in resting heart rate can mean you are in a state of fatigue or over training or are becoming ill. Professional athletes often keep a diary listing resting heart rates to see trends and changes to monitor their conditioning.

Top professional endurance athletes have huge hearts and huge stroke volumes and can have heart rates down to less than 30 beats per minute! Measure your own now - what's your pulse? 60-65 beats per minute? More? As a rough guide anywhere under 70 BPM is 'good', below 60 is very good and below 50 hints at a very impressive heart. A Tour de France cyclist's heart is beating once every two seconds and is meeting all his demands!

Motocross riders should also aim to lower their resting heart rate and increase their stroke volume. This will allow you to keep up that first lap speed throughout the course of the race without fading. It will also help reduce arm pump and delay its onset as more oxygen is reaching the arm muscles and the lactic acid is being more efficiently dispersed and broken down.

Maximum heart rate is also a good guide to effort levels - this is usually in the range of 190-210 beats per minute. You might think that maximum heart rate increases with fitness training but in fact it may not be altered greatly. It declines gradually with age and is affected by heat and health but it is a very good measure of fitness levels as we can see the percentage of your maximum heart rate (effort level) you need to put into a given exercise and how long you can sustain very high effort levels. Some endurance athletes will perform at close to 95 per cent of their maximum heart rate for prolonged periods.

I have done research into the heart rate levels achieved during a motocross race and the graph is interesting to see - over 180 beats a minute for 35-40 minutes! This is 90 per cent of the rider's maximum effort and just goes to show how hard a motocross race is physically. When we are training we need to know the effort we are putting in so we can train at the most appropriate levels...,

• 50-60 per cent maximum heart rate - low intensity exercise such as walking or slow jogging.
• 60-70 per cent maximum heart rate - medium intensity exercise such as running or cycling at a steady pace.
• 70-80 per cent maximum heart rate - high intensity exercise such as running up a hill or fast steady cycling.
• 80-95 per cent maximum heart rate - very high intensity exercise such as hard sprints, competition intensity exercise or a motocross race.

Using these levels gives a guide as to how we need to train. If we want to train for competition and are only challenging ourselves at low heart rates we will not improve or be prepared. However, we can't go straight into training at 80-90 per cent maximum effort straight away! We need to train appropriately...

The levels at which we burn most fat are quite low - 50-65 per cent maximum. So if we want to lose weight and are new to exercise we must start there, even if we want to prepare for all-out hard efforts. If we want to gain the most improvement in our endurance and efficiency, 75-80 per cent maximum is the most appropriate level.

This area of training is something that is important and should be discussed with a trainer to get the most benefit. It is an in-depth subject that I can't go into sufficient detail here.

As you can see, keeping to a set heart rate will actually keep you progressing as the heart gets bigger and pumps more blood per pump, the heart rate needed comes down for each given exercise level. So keeping the heart rate steady does keep intensity gradually improving. However we do want to alter heart rates for various forms of training - something that a training plan will incorporate for different times of the year and different disciplines.

The heart is a complex organ but understanding it is important to helping you improve your training and your performance. This is my general guide to start you off with your heart training.

Work out your 'theoretical' maximum heart rate using the equation 220 minus your age (I am 26 so in theory my maximum heart rate is 194). This is a rough guide but is a starting point and you can work out your different training levels from it.

Buy a heart rate monitor. They can be found in proper sports shops and on the internet etc and need not be complex in design. You just want to know what your heart is actually doing when you are doing various activities such as training in the gym or riding your motocross bike.

Plan your training at the appropriate training levels. If you are new to training you need to aim to go for a fairly prolonged period and this will be impossible at high heart rates. Often people run at high heart rates and so can only do it for five to 10 minutes. Lower the heart rate and go for longer to start with. If you want to get a good grip on your fitness and health levels try measuring your resting heart rate and check this from time to time to see how it changes.

And treat your heart well! Fatty foods, smoking and too much alcohol all affect the blood supply to the heart itself and the pressure at which the blood returns to the heart. These will greatly hinder your performance and can be dangerous if you try to exercise at high levels.

Being aware of what your heart is doing and why when you are riding does help you appreciate the kind of effort that goes into racing. It is hard work! Training your heart to adapt to these kind of demands is important and regular sessions at the right heart rates will make the riding easier and your results better!