written by Scott Keast, Education and Safety Co-ordinator
Until recently the best method of determining fitness level was best indicated by monitoring heart rate during exercise, and for the average recreational cyclist it remains a very good way of determining how one’s condition is developing. The introduction of the power meter and portable lactate monitoring in combination with heart rate represents the state of the art methods of keeping tabs on conditioning, but the technical aspects and expense of the two former methods put them out of reach for most cyclists.
Heart rate monitors on the other hand have become increasingly sophisticated and more affordable. Wrist units with a good set of features cost 25% of what similar units cost 10 years ago and offer ECG accuracy. Units from manufacturers, such as Polar, Timex, Garmin, and Suunto offer an excellent, objective method of assessing how one’s body is coping with the load placed on it by cycling.
Where do you begin?
A good place to start is with determining your maximum heart rate. This proves to be more difficult than it first appears because the old formula of 220 minus your age has proven to be wildly inaccurate and of little use. More recent research has found that this formula can have an error of up to + or – 21 beats per minute (bpm)! More recent formulas have been developed that are much closer, but still miss the mark by quite a wide margin. They include:
205.754 – (0.734 x age) with an error range of + or – 7.2 bpm!
205.8 – (0.685 x age) with an error range of + or – 6.4 bpm! (Friel)
The simple fact is that each individual’s body has a unique response to workload. For example using the old 220 – my age gives me a maximum heart rate for cycling of 172. But experience has shown my maximum heart rate to be 183 and this correlates with my maximum heart rate from my heart rate monitor! (A well documented and proven algorithm is used to arrive at this figure, based on sex, age, body weight, height and heartbeat patterns.)
So how do you determine your maximum heart rate?
First of all if you are over 30 years of age and/or have been quite sedentary up to this point, go see your family doctor for a physical and his/her recommendation as to how to proceed with exercise. If you get the green light, then you may do some field tests to push yourself to your maximum heart rate but these definitely fall into the category of “dedicated and driven”. At the end of these tests you will be seeing stars and may even taste blood from the extreme rate of respiration – I’m not kidding on this point! Needless to say this can be dangerous and I do not recommend that this be undertaken. You may unintentionally come very close to seeing your maximum heart rate while out on a regular club ride – this is how I arrived at my maximum heart rate. Quite simply you go out for a ride and after a good warm-up and an hour of tempo riding find a short steep hill and sprint up the hill like you’re possessed! The highest reading that you see on your heart rate monitor is likely within 6 bpm of your absolute maximum.
Wait a minute – why is maximum heart rate so important?
Well, it is one of the best ways of determining your personal training zones (which are very important), but it poses the most risk and generally isn’t recommended.
Okay so how do you find your personal training zones without summoning the Grim Reaper?
By finding at what point your body begins to go into a self-limiting phase where the pulmonary and cardiovascular systems are no longer keeping up with the rate of cellular function within the muscles. This self limiting point is called your anaerobic threshold. This is the point when the cells begin to operate with insufficient oxygen, hence the term anaerobic (absence of oxygen) as opposed to aerobic (in the presence of oxygen). It is possible to operate at or slightly below your anaerobic threshold for perhaps an hour. By training around this heart rate it is possible to extend or raise your anaerobic threshold, but it remains time limited.
Part of what limits your time at your aerobic threshold is because the body is beginning to rely on the anaerobic process of glycosis more and more, the cells release a by-product called lactate and current research would indicate that there are hydrogen ions released as well. It is believed that these hydrogen ions are what create the burning, heavy dead feeling that one associates with high intensity efforts. In the past it was believed that it was the lactate that created “the burn,” but lactate is actually recycled, in a sense, and allows for extended energy production by the cells (see Energy Systems).
So, to find your training zones might take a little research and experimentation on your part. You may also have a friend help you as well. For this, you will need a heart rate monitor and some experience at rating your exertion. These rating systems are very subjective, but as you gain experience you will find that you can fine tune these to the point where you can monitor your body quite well without constantly checking your heart rate monitor. Here is one common Rating of Perceived Effort (RPE) scale:
- Extremely Easy – Restful breathing – able to sing
- Very Easy – Can talk in complete sentences
- Easy – Can talk in broken sentences
- Moderate – Talking first becomes difficult
- Somewhat Hard – Heavy breathing begins
- Moderately Hard – Deep breaths, talking is avoided
- Hard* – Deep and forceful breathing*
- Very Hard – Laboured, cannot talk
- Very, Very Hard – Very laboured breathing
- Extremely Hard – Gasping for air
To establish your anaerobic threshold, it is most convenient to do the test on a exercise bike, spinning bike, mag trainer or wind trainer. It is best to control as many variables as possible, including your level of hydration, rest, fueling, ambient air temperature and humidity, and load. Attempting to do this outside on a course introduces too many variables.
Your friend is going to monitor your breathing, record your RPE, heart rate and adjust the load if necessary.
- Begin by warming up for 10 – 15 minutes.
- Set the equipment so that the load is very easy (RPE-2) and begin riding at a specific speed or cadence. You are going to maintain this level of output until you no longer can.
- Every minute raise the machines resistance and at the end of that minute have your friend record your breathing pattern, what you believe your exertion to be, your heart rate, and the load setting.
- When your breathing becomes deep and forceful your friend should be able to detect this change in your breathing pattern. This is your ventilatory threshold (VT) and corresponds very closely with your lactate threshold or an aerobic threshold. Record all of the same information but be sure to mark the readings as the VT.
- DON’T Stop! Keep going until you can no longer maintain the workload.
- Do a cool down of 5 to 10 minutes.
Compare where you felt that your breathing became deep and forceful with where your friend recorded an RPE of 7 and if the two points agree then you have found your anaerobic threshold (AT).
Now your training zones are easy because they are based on your own personal AT. The system that I have found to be very good and very safe was developed by Andie van Diemen (BA-Physical Education, MSc Human Movement Sciences) and Jabik-Jan Bastiaans (MSc – Human Movement Sciences). Van Diemen and Bastiaans developed what they called the Maximal Lactate Steady State (MLSS) which for all intents and purposes is very much like your anaerobic threshold (AT), which you already know. Just plug your numbers in and do the calculations. The percentages on the next page are of your MLSS – not your maximum heart rate.
|Training Zone||Type of Trainign Limits (%) of your MLSS||Personal Heart Rate|
|1||Active Recovery||60 – 75%|
|2||Endurance Training||75 – 85%|
|3||Intensive Endurance Training||85 – 90%|
|4||MLSS Training||95 – 100%|
|5||Power Training||All out|
Note that unless you are training for competition cycling events, you shouldn’t ever see your maximum heart rate unless you get caught out in a brutal headwind or on a longer steeper climb than you expected. The Power Training zone should be trained minimally by touring cyclists. The bulk of your rides should focus on zones 2 and 3 early in the season to build an aerobic base, and then gradually mix in more of zone 3 and 4. Your time in zones 4 and 5 should be interval training so as to minimize the risk of injury and over-training. Intervals should be generally as follows:
Very long tempo rides where the average heart rate stays within the limits of zone 3 for an hour or more.
Long equal intervals (e.g. 10 minutes) in the middle of zone 3 followed by an equal number of minutes in the centre of zone 2.
Short intervals of 2 to 5 minutes in the centre of zone 3 followed by incomplete recovery in the centre of zone 2 (30 seconds to 1 minute)
Long intervals (e.g. 6 to 12 minutes) just below your AT with recoveries in the order of 25% of your work interval.
Short intervals (often measured in seconds) followed by a recovery in zone 3 of 3 times the work interval (e.g 30 sec onds all out followed by 90 seconds where the heart rate drops into and stays in zone 3).
If this all sounds a little involved for you, are there other ways of calculating your target heart rate zones?
There are many places on the web that you can access, but most of them are the old 220 minus you age. However, they are safe to use to get you started. One that you may want to try can be found at www.polarca.com Try some of these, then use the formulas that were presented earlier on. Compare them and see if what they present on paper jives with what you experience out on the roads.
Some of the higher end Polar Heart rate Monitors can perform an easy test that takes 5- 7 minutes and has proven to be very accurate at predicting maximum heart rate, target zones, and will even give a close approximation of your Maximal Oxygen Uptake (VO2 MAX) which helps to quantify your fitness level.
Finally, if you have $200 to $300 dollars just burning a hole in your pocket you can go to either Grant MacEwan College or the University of Alberta and have a full blown stress test that will absolutely nail your aerobic threshold, anaerobic threshold, VO2 MAX, and all of your target heart rate zones. Don’t forget that your body will improve on those figures very quickly, and in six months or a year you’ll need to do it all again to determine the new values.
Ultimately you just have to find one method that gets the results that you are after.