Heart Rate
It's all about heart. We've all heard the phrase and on most occasions it is meant as a drive, or willingness to achieve. However the most important aspect of any riders 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 it 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 one needs to understand that training improves its function and thus how we can improve performance.
The heart is made up of 2 distinct sides, and 4 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. This is controlled by nerves and valves and is a remarkable feat of human engineering! 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 sending 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).
To increase the level at which we can work, the duration at which we can sustain this, and ultimately increase the level at which we can perform is limited by the heart. Training the heart is therefore vital and must form the back bone 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 of 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 of 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. To think a Tour de France cyclist's heart is beating once every 2 seconds and is meeting all his demands! And it is not just traditionally endurance athletes who work to maximise their hearts potential. 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 off. 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. As mentioned previously, maximum effort over a period of time is limited by the heart being able to supply the demand and so at full effort and at when you are just about to call it a day and pass out - that is your maximum heart rate! This is usually in the range of 190-210 beats per minute. One 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% 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% of the riders maximum effort and just goes to show how hard a motocross race is physically. When we are training we need to know the effort levels we are putting into the training so we can train at the most appropriate levels:
- 50-60% maximum heart rate: Low intensity exercise, walking, slow jogging.
- 60-70% maximum heart rate: Medium intensity exercise: Running, cycling at steady pace.
- 70-80% maximum heart rate: High intensity exercise: Running up a hill, fast steady cycling.
- 80-95% maximum heart rate: Very High intensity exercise: Hard sprints, competition intensity exercise, Motocross race.
Using these levels gives a first 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% maximum effort straight away! We need to train appropriately.
For example:
- The levels at which we burn most fat are quite low, 50-65% 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% maximum is the level most appropriate levels.
This area of training is something that is important and should be discussed with a trainer or a specific text to get the best benefits to your training. 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, different sports, and different disciplines.
The heart is a complex organ but understanding it is important to helping you improve your training and your performance. Things need not get complicated or go into too much detail, so use my guide to start you off with your 'Heart Training':
- Work out your 'theoretical' maximum heart rate. Use the equation: 220 - 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, 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 - training in the gym, riding the motocross bike etc and will help you train accurately.
- 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 5-10 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.
- Treat your heart well! Fatty foods, smoking, 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 the bikes does help you appreciate the kind of effort that goes into riding and 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, the results better and above all- it will be more fun!
