By Arnie Baker
Heart rate monitors allow you to observe your heart rate while working out. This helps training, providing immediate feedback about aerobic exercise intensity.
Why Use a Heart Rate Monitor?
As with all measures of intensity outlined above:
- Use a heart rate monitor to help design your training and racing programs.
- Use a heart rate monitor to help ensure that you work according to plan. A monitor helps make sure that you work hard enough when you want to work hard. It also helps make sure that you do not work too hard on easy days.
- Use a monitor to help analyze how you feel and what happens to your body in training and in racing. Monitors do not necessarily change your training, but may help allow you to understand what is going on.
- Use a monitor to help motivation. The feedback provided is engaging for many riders.
Maximum Heart Rate
Determining maximum heart rate is the first step in developing a heart-rate training program.
Why Care About Maximum Heart Rate?
For most riders, heart rate zones for aerobic, threshold and anaerobic work are determined from maximum heart rate. Some coaches and athletes attempt to determine maximum heart rate a few times a year to set training intensities.
Maximum Heart Rate Defined
Maximum heart rate is the highest heart rate you can achieve. For most riders, maximum heart rate is the highest accurate number seen on their monitor during the last year. Electromagnetic transmitters are a common source of false readings.
Individualize Your Numbers
220 minus your age, and other similar formulae are useless. The statistical average for the population is wholly unsuitable for the individual. It is like saying the average person is 5’9” tall, so all bikes should be made 55 cm.
Maximum Heart Rate Changes
Maximum heart rate is not a static or fixed number. The unfit may not be able to achieve their genetic potential because of a lack of muscular strength or energy to work hard. Their maximum heart rate will increase as they become fitter.
Once fitness exists, maximum heart rate does not change much, but it does change. Elite athletes often have a lower maximum heart rate during their competitive seasons.
Maximum heart rate is sport- and climate-specific. Maximum heart rate is higher when vertical than when horizontal, and higher when more muscle mass is engaged. Therefore, maximum heart rate running is higher than maximum heart rate cycling, which in turn is higher than maximum heart rate swimming.
Finding Your Maximum Heart Rate
To obtain a maximum heart rate value, you need to be:
- Well warmed-up.
- Motivated to make a maximum effort.
Why rested? Rest provides for recovery from previous exertion. With muscle fatigue/soreness or a lack of glycogen, it is not possible to produce a maximum effort.
Why a warm-up? Maximum heart rate depends upon maximum cardiovascular demand. If you are not well warmed-up, there is less blood flowing to your working muscles (the pre-capillary sphincters are not all open)—maximum effort cannot elicit maximum response.
Why motivated? Many people only see their max in a race or a test in which they are motivated. It is often difficult for riders to test their max when by themselves. There are a number of different ways to find your maximum heart rate. Here is one way:
Warm up for at least 5 to 10 minutes. After working at a moderate pace for three minutes, increase your effort by about 10% every minute.
Cyclists on an ergometer can increase power output by about 10% each minute.
Cyclists riding on a velodrome or open road: Since power requirements rise between the square and the cube of speed, a 10% increase in power each minute does not mean a 10% increase in speed. Increase cadence by 3 – 5 revolutions per minute, or increase your gearing by one gear of difficulty every couple of minutes. When you get to the point that it is extremely difficult to continue at pace, sprint as hard as you can for 30 seconds. Watch your heart monitor. This value should be close to your maximum.
Resting Heart Rate
Resting heart rate provides a tool for monitoring fitness and recovery.
Morning Resting Heart Rate
Determine resting heart rate by counting or monitoring your heart rate while not engaging in physical activity. This is usually measured first thing in the morning while lying still in bed.
Conventional wisdom states that resting heart rate is a measure of fitness and recovery. As you get fitter, your resting heart rate falls. When you are not recovered, your resting heart rate rises.
Use resting heart rate as tool in evaluation, but do not be spooked by high values: Some riders have their best performances on days that their resting heart rates are high.
Factors Affecting Resting Heart Rate
Dehydration, fever or other illness, drugs, stress, or the environment might raise resting heart rate.
For many riders, the discomfort of a full bladder, the physical activity of getting up to urinate, or the jarring of an alarm clock will raise heart rate. Resting quietly in bed for several minutes after returning from urinating or turning the alarm clock off will give a more accurate reading.
The value measured while lying flat on the back is often slightly lower than that measured while lying on the side.
Threshold Heart Rate
The heart rate that you can sustain for prolonged efforts is important in prescribing exercise training and as a measure of fitness.
Thresholds are Variable
Elite athletes can sustain 92% of their maximum heart rate in events lasting about one hour. For events longer than this, the threshold will be lower. For shorter events, the threshold will be higher.
Elite athletes may sustain efforts corresponding to more than 92% of their maximum heart rate for one hour. In contrast, once beginners have the strength and endurance, they ride at about 80% of their maximum heart rate.
Since a century represents many hours of work, the level one can sustain will be considerably less. Elite racers finish a century in about 4 hours, averaging more than 80% of maximum heart rate. Beginners finish a century in more than 8 hours, averaging 65% to 75% of maximum heart rate.
Factors Affecting Heart Rate
A variety of individual and environmental factors affects heart rate. Interpreting heart rate in the context of these factors provides better insight into the meaning of heart rates.
Fatigued riders may ride at lower heart rates with the same power output.
Temperature and Humidity
Heart rates may be one beat higher for every two or three degrees above 70° F. Cold weather results in lower heart rates.
Heart-rate recordings at different temperatures are shown in Figure 12.
Threshold and maximum heart rates are reduced about one beat for every 1,000 feet of elevation for sea-level athletes when at altitude.
Dehydration places increased demands upon the cardiovascular system. For a given power output, heart rates are increased.
As most athletes become fitter, they improve their cardiovascular function and increase their sport-specific muscle mass—they are able to achieve higher maximum heart rates.
As athletes become fitter, they are able to produce more power for a given heart rate, or produce the same power with a lower heart rate.
Medications and Drugs
Drugs may decrease or increase heart rate. For example, beta-blockers like propranolol (commonly used to treat high blood pressure) can decrease heart rate and thyroid medication can increase heart rate.
Illness and Disease
Medical conditions can decrease or increase heart rate. For example, thyroid disease can decrease or increase heart rate, and illnesses with fever generally increase heart rate.
Heart-Rate Training Zones
You can establish heart-rate training zones based on percentages of your maximum heart rate.
Table 5 shows a simple zone system.
Riding under 65% of your maximum heart rate. Easy riding. If your maximum is about 180 beats per minutes, your noodling rate is under 120 beats per minute. This is recovery riding.
|% Max Heart Rate||Effort|
|Noodling||< 65%||Recovery, easy, “below pace”|
|Aerobic||66% – 85%||Group rides, “pace”|
|Threshold||80% – 92%||Time trials, “above pace”|
|Anaerobic||> 93%||Surges, jumps, intervals, sprints|
Your century pace is within this range. Working between 66 and 85% of your maximum heart rate. You are training aerobically—“with oxygen.”
Heart rate economy will improve: As you become fitter, you will be able to accomplish the same work at lower heart rates. Put another way, you will be able to accomplish more work at the same heart rate.
Recovery heart rate will improve: The fitter you are, the faster your heart rate will recover from hard efforts.
Working between 80 and 92% of your maximum heart rate. You are at a transition between aerobic and anaerobic work. This level of work is sustainable for efforts up to an hour. Training at this level some of the time will improve your fitness for shorter and for longer events.
Threshold level will rise: New riders can commonly sustain 80% of maximum heart rate for one hour. As fitness improves, athletes can maintain levels closer to 92% of maximum heart rate.
Anaerobic Training and Racing
Heart rates 93% or more of your maximum heart rate. Efforts that you cannot keep up very long. This is very hard work. You get these redline efforts in jumps, intervals and sprints. Not the exertions needed by most commuters, weekend riders, or century riders.
Training Time Needed to Progress
As said previously, aerobic training begins at about 66% of an individual’s maximum heart rate. To maximally train the aerobic system, riders need high-aerobic work—80% to 85% of maximum heart rate.
Once you have built a base of a thousand miles or more over a few months, you can aim to train at this intensity two or more times per week. Aim for a cumulative total of two or more hours per week.
Endurance may be improved by training at lower intensity levels, but maximal oxygen uptake may not increase. Spending more time training at high-aerobic levels may be productive during some training phases. During these phases, riders may train at high-aerobic levels up to six hours per week.
There is a limit as to how much time riders can spend at high-aerobic levels because there is a limit to high-aerobic energy sources. Intramuscular glycogen is a limiter. There is also a neurohormonal limiter. High volumes of high-aerobic work should not be performed routinely because of overtraining risk.
Racers need training at 86% to 92% of maximum heart rate to reach the limits of their aerobic potential. Training near this level overlaps with anaerobic training at times; this is threshold training. When training at such very-high aerobic levels, reduce the overall volume of aerobic work.
High-level aerobic training is not required for everyone. Riders are commonly able to complete successfully a hilly century without maximizing their aerobic training.
Heart-Rate Training Isn’t Everything
Although heart-rate monitoring has revolutionized training for many, it is not a be-all and end-all.
While heart rate is one measure of training intensity, it is not always the appropriate way to measure intensity. It is an excellent way to measure aerobic intensity. It not the best way to measure or evaluate strength training, neuromuscular fitness (e.g. leg speed or torque), or anaerobic work.
Not everyone finds that heart-rate monitoring improves performance.
Heart Training is Specific
When you are training, you must consider the purpose of your training. Do you need to monitor heart rate? Are you training aerobically? Or are you training strength? Or anaerobic power? Or skills? Or leg speed? Or recovering?
You will end up stronger by having “separate” workouts or aspects of workouts for leg strength or power. The legs develop more strength in bigger gears. However, when you ride big gears, the intensity of your workout is not matched by your heart rate.
For example, riders strength train in big gears going up hills at 75% of maximum heart rate. Exertion may be similar to that perceived while riding at 85% of maximum heart rate in a smaller gear.
Unreliable for Anaerobic Work
Although heart-rate readings of 93+% of your maximum are anaerobic, not all anaerobic efforts will result in heart rates in this range.
High-level aerobic work preceding anaerobic effort is generally needed to see such high heart rates.
Your heart responds to changing exercise intensity, but this response lags behind true effort. In addition, monitor readings lag true heart rate. These lags mean that you may already be recovering before your monitor has the time to reflect true effort.
Don’t Be a Slave to Your Monitor
Riding under 65% of your maximum heart rate? You are not training your heart.
That may not be necessary. Training with new aero-bars? Perhaps you want to adapt to the position, not train aerobically. You might ride an easy workout at a heart rate of 110 beats per minute. You are training. You are training your back muscles, your forearms, etc. You may be resting your legs, and recovering from a recent hard ride. Recovering—that is an important part of training too!