Heart Rate vs. Watt: the art of performance monitoring in cycling

On the bicycle, the cyclist is the “engine” thus both Heart Rate and power must be constantly monitored in parallel to save energy and avoid to exceed the value that have been previously determined. Spending time at the PC analysing training data will teach a lot about ourselves and they will help us to put together feelings and numbers.

Why heart rate and watts are so important to monitor performance in cycling? Why should they be measured together to fully understand the cyclist's performance? How can Technogym equipment help the cyclist improve sports performance?  Let's look at it in this article:

• Brief history of power meter
• Why Power Meter is important?
• Why Heart Rate is important?
• Wy heart rate and power rate are both important

Brief history of power meter

In the past almost no pro cyclist used to measure to power output. The most advanced shyly tried it during training session but not in competition. Nowadays, almost every rider in the peloton use some sort of power meter, they can be hidden in the crankset, in the bottom bracket, in the pedals or in the rear hub. They are connected to a cycle computer that shows real time data but also acts as storing unit that save all the records for further, detailed analysis.

This technology has contributed to reshape the way cyclists compete. The time of bravery and courage and heroic break away is gone and in these days everybody keeps his eyes on the cycle computer gauging the watts in order to manage his power in the most efficient way.

Why power is important

Watt is the only objective measure of the effort made by the cyclist. Even for the most experienced ones is in fact very difficult to “feel” the effort. Feelings are related to a plethora of subjective and objective issues and relying on them, without the support of an objective data, can lead to generate too much or too little power. Power output can be easily measured in the lab following specific test protocols that take in account other parameters such as HR and oxygen consumption.

Mycycling and Skillbike offer an accurate reading and measurement of the power output. Different testing options allow to determine the power at Anaerobic threshold. With Skillbike is easy to maximise the efficiency of your ride with real-time feedback on Cadence, Power, Speed, Distance, Gradient, Heart Rate, Gear and Gear Ratio. Knowing these values is fundamental for proper and efficient training session.

Results indicate the level of fitness, HR and power zones and anaerobic threshold values. These data create the individual performance profile and must be taken in account during training and racing. To make some example, if the training program says 3 x 4 min at AT and the power is 300 watt, the cyclist will do the intervals focusing just on the power output being sure to precisely meet the target.

During the competition, if there is an attack on long climb and the same rider sees that in order to stay with the fugitive he has to push 350 watts, well, he must realize that he must keep his own pace or he will blow up in a few minutes.

Why heart rate is important

Until now, we have not talked of heart rate despite it is the most known and used biometric. Is it not relevant? Not at all, it is important to understand the physical condition and reaction of the body to the sustained effort. That’s because, how we said before, Heart Rate is a subjective data that can be influenced by several factors: stress, temperature, glycogen availability, recovery, hydration, altitude. Poor recovery can increase the heart rate at rest, whilst glycogen depletion can reduce Heart Rate at a given effort.

Altitude above 1800-2000 m. can progressively increase heart rate for the diminished O2 in the air and hot weather also push the value upward.

Heart rate is collected by a chest strap that relieves the electrical impulse generated by each contraction of the cardiac muscles and sends it to the cycle computer. Memorized data can be downloaded at the end of training or racing and can be visualized in correlation to other parameters such as power, speed, cadence, elevation, speed and temperature.

Mycycling and Skillbike are compatible with all blutooth heart rate monitor. In this way heart rate can be taken under control or can be used to create a heart rate controlled session.

Why power meter AND heart rate are important

It’s time to put together data and wrap up some conclusion. First, Power and Heart Rate must be analysed together to fully understand human performance. Cyclists have now accessible technology to elevate the level of monitoring of their effort. In order to give practical advice, I’ll separate the advantage of real time monitoring vs. ex post data analysis.

Whilst on the bicycle, data reading is important to understand how the “engine” is functioning. If you are equipped with power meter and HR, set the power and wait for the HR to hit the expected value. This way, you’ll be sure to never overcome the limits of your performance.

Using the simple analogy between HR and RPM it will be easy to understand that in normal conditions the higher is the HR the more calories will be used. On the opposite, heart rate that is “lazy” to raise means that the red light of the gasoline level is flashing and we are about to run on empty of carbo, the next scenario will be a significant drop of power output.

For this reason, heart rate should be constantly monitored during high mileage session or races. This will allow to prevent carbo depletion and will save us from hitting the “wall”.

Off the bike analysis will give a complete picture of the session/race. We’ll see if the HR and power have been constant during the climbs or if there’s been a significant decrease which is a sign of fatigue and glycogen depletion. We can also check which has been the highest HR value and the average 20’ power. Average HR of the session indicates cumulative load on the body and will helpful to indicate recovery time: the higher and for the longer time HR has been, the longer will be the recovery.