Sport

Running Training with Power

An introduction to running power, how it relates to force and speed, and how it complements pace and heart rate when assessing training and performance.

Date 07.05.2019

Author

maq

Topics

Through a series of 6 articles I will offer you some basic and advanced knowledge about running training with power. You will be able to learn about the new methodology that is revolutionizing the world of running.

I have been working with athletes and triathletes, both recreational and elite, for over 2 years who use power as a tool to quantify their running training. I will show you how you can be more efficient in your day-to-day life, how to optimize your time and money, and logically, how to improve your performance.

If you have come this far, it is because you are an athlete with concerns and you want to continue advancing in your training process. I'm going to help you understand how a running power meter can help you. You are probably thinking what is running power?, what is it for me?, how do I introduce it into my training?

What is power?

In its simple form we can define it as the rate of doing work: it is the measure of the amount of work you are doing and at the speed you are doing it. You know, for example, that the higher the speed you run a certain distance, the greater your wattage production will be to generate that speed (almost always, in future articles you will see that it cannot always be like this if we compare different ways and different times of the season).

The work you generate by running measures the force you're applying to move your body from one place to another. This force is applied through your legs, knees, ankles, feet that get a return of energy with the ground, which causes a displacement. We feel the force, we don't know how much it is, but it is there. Newton's Third Law (action-reaction), which tells us that every action of force receives an equal force, but in the opposite direction. This is the force with which we move, the force received by the ground in our body structure.

We can define work as the product of the Force by distance:

W = F x D

If we go back to the beginning of the article, I related work with power, therefore, we can express the following:

P = W/T

So we have that the work you generate while running divided by the time it takes to do it, is the amount of power you produce.

Now, when we run we refer to the speed at which we run and the distance we travel, this is nothing more than the relationship with power, since distance is obtained from the product of Speed times Time, obtaining:

D = V x T → P = (F x (V x T)) / T → P = F x V

This means that the power is equal to the force you apply times the speed at which you apply it, basically. And where do you apply the force when running, well, on the ground or track, and you apply it at a certain speed, related to the cadence (strides/minute).

Generally speaking, if you are able to apply high power for a long period of time, you are in good shape. Your ability to apply high power values over long runs, and replicate these values for longer is one of your goals to know that you are improving. Being able to measure the power you generate over time can help you see how well your training task is being performed.

With a running power meter you can see the watts you generate in each stride, it's that easy. And not only that, but we know that 1 watt is equal to the generation of 1 joule of energy per second:

W = j / s

So you will also be able to know how much energy you have consumed in each training and competition task, and relate this to nutrition and the correct energy intake in each case.

Power is one more measure of quantifying training load, along with heart rate and pace. All runners (athletes, runners) use one of these measures or several at the same time. But why power training then?

The answer is because power is the quantitative and qualitative measure that is least influenced by the terrain, elevation changes and hills When we go up a hill our heart rate increases and our pace drops, the opposite happens when we go down a slope, so these measurements would no longer be as reliable. To that we add the "slow component" of the heart rate, which means that heart rate does not respond instantly to effort and can take seconds or minutes to react, so we would also lose real data on certain occasions.

With power that does not happen, it remains much more stable in these situations and gives us an instant response to each stride, whether uphill, downhill or flat. We will not lose data and the load or stress of training will be much more real and adapted to our level, our physiological characteristics and our energy expenditure.

Running power, pace, perceived exertion and heart rate across terrain

This figure illustrates the differences between heart rate, subjective perception of effort, pace and power, according to the different types of terrain with slopes and flats.

All this does not mean that heart rate and pace are not valid for training, far from it, in fact, they provide us with a lot of information combined with power, as we will see in future articles.

And now, how do I assess my performance and evolution using watts?

Several indicators can show your fitness level at a specific time:

An increase in watts over a given duration (or distance) is usually associated with an increase in performance.
An increase in pace (min/km) or speed (m/s) while maintaining the same watts indicates an improvement in performance
A decrease in watts at the same rate or speed indicates an improvement in performance

Likewise, power training allows us to address important technical issues (there are many others that we will mention in future articles). This is how we can obtain:

An increase in Horizontal Power at the same rate indicates an improvement in performance
A decrease in the total power generated at the same speed indicates an improvement in performance (related to Running Effectiveness, RE).

References and online resources:

Palladino Power Project
Palladino, S.: Understanding Running Effectiveness and Its Uses
Run with Power. Jim Vance, 2016
TrainingPeaks
Stryd
Xan Suarez Triathlon Coach

*In the next chapter we will address aspects such as your Power Threshold in running, how to define it, how to obtain it and what to use it for. We will also cover aspects such as power peaks, quantification of the intensity of the session and the intensity factor.