Training intensity - measuring intensity

The more we understood how to design a training process the more we relied on devices that will help us gauge training intensity in order to be able to precisely stress a desired aspect of the athlete’s physiology.

Heart rate monitors started gaining popularity but proved to be an unreliable witness quite often. That’s why sports scientists and coaches have devised multiple methods that when used together give us a better way of crafting the right workouts for our athletes.

How we can measure intensity is the topic of todays blog post.

Pace

One of the first ways of measuring intensity was by using pace. Even though it’s a great way of quantifying intensity, in some endurance sports it has been substituted for other ways. It may still be the best for swimmers and runners but for cyclists it can be an imperfect measure because of great variability in terrain when training outside.

Before the advent of GPS watches it was quite hard to measure pace effectively. Athletes would need to do a lot of mental arithmetic while swimming or running in spaces of known distances. Once they complete a full loop, they would know their time and be able to figure out their pace. Then they could adjust their effort and repeat the process again for the next loop.

You can see that this was quite an inefficient process but thanks to technology we can now instantly see our current pace on GPS watches. Even swimming in pools is made a lot easier because those watches can detect swimmers pushing of the wall and keep counting the distance for them.

An additional level of precision has been added by using accelerometers that are tied to a runners shoes and when combined with a compatible watch can give an even better measure of pace.

One negative side of measuring intensity by pace is that athletes start relying too much on them and keep constantly checking their watch to see if they are on target. This takes away from developing the ability to listen to their body as well as lower overall enjoyment.

Rating of perceived exertion (RPE)

When an athlete reaches a certain level of experience, they develop the ability to asses the their level of exertion based on how they feel alone. They don’t have a need for heart rate monitors, watches, or other gizmos.

The great thing about this is that it is used by pretty much all athletes whether they are aware of it or not.

There are many ways on how someone can quantify their perceived exertion. One of the most popular is a simple 1 - 10 scale where 1 means no exertion at all while on the other hand a 10 means an all-out effort that can be held for just a few seconds. Over time, athletes can develop the for where they are on this scale during every exercise and can precisely gauge their effort based on feeling alone.

Another way of measuring RPE is by using the Borg Rating of Perceived Exertion. This scale was designed for young middle-aged athletes and goes 6 - 20 where 6 means no exertion at all while 20 means all-out effort.

The range was chosen because when multiplied by 10 it can roughly equate the actual heart rate of an athlete but as we will see next. It’s not that simple.

Heart rate

Ever since the 1980s and the introduction of wireless heart rate monitors, athletes, especially in endurance sports have embraced this technology and tried using it to their advantage.

Athletes and their coaches learned when an athlete has fully recovered, how hard they could, sometimes go, and measure progress and gauge efforts on long distance events.

Unfortunately, heart rate is a somewhat opaque window into the state of our body. There are quite a few factors that can have an impact on heart rate like temperature, sleep, or even what an athlete ate before a training session.

When used intelligently, heart rate can be a great tool. It can let an athlete know if they are going to hard, if there was enough rest between interval sessions, and if the overall fitness is improving.

Determining what heart rate to use and base a training session off of. One approach is to use the maximum heart rate an athlete can achieve as the benchmark and work in certain percentages of that heartrate.

This approach has a one big shortcoming. We have defined the anaerobic, or lactate, threshold as the point at which the body starts using anaerobic processes to produce energy. The heart rate at that point in highly individual which means that one athlete can have their anaerobic threshold and 87% of their max heart rate while another athlete could be at 92% of their max heart rate.

If we have both athletes train at 90% of their max heart rate, one will be working aerobically, while the other athlete will work anaerobically, and thus stressing different mechanisms in their body. That’s why basing training intensity based off of anaerobic threshold heart rate is a much more effective way of defining intensity zone.

One more issue that training exclusively by heart has has is that different sports target different muscle groups and are executed in different positions and will in turn cause the athlete’s heart rate to be different. A Zone 2 for cycling might be at around 130 to 140 BMP but the same would rise to 140 to 150 for a runner.

That’s why heart rate combined with, for example RPE or power (something we will cover next) can give an athlete much better insight into how hard they should work.

Power

One of the most objective way of quantifying intensity is by using power. Power meters for bicycles have been on the market for a long time and there are some products now which promise to do the same for runners.

Power is very closely related to performance because it takes out a lot of the variables out. It doesn’t matter how hot it is, if you are on a flat road or going uphill, if there is wind or not. The only thing that a power meter knows is how much you are putting out.

Heart rate is sometimes slow to catch up to the actual work so when doing some shorter intervals it can take a bit until you are in the correct zone. Once you slow down it, again, takes some time for your heart rate to go down which makes it challenging to train properly.

With a power meter these things don’t happen. It takes just a second or two for you to hit a target power zone and after that it’s all about staying in that zone.

Power meters are one of the best investments an endurance athlete can make and, although, it’s not cheap, it provides the best return on investment when it comes to being able to monitor performance.

If we add to that RPE or heart rate, we can pinpoint where we want our athletes to be and precisely target a certain aspect of their fitness.

Lactate

One of the latest improvements in availability is being able to measure lactate in our blood. After finishing certain intervals, blood is drawn from the finger or earlobe and later analyzed.

Just a few years ago this was only possible in lab conditions but has now been available for the mass market. It’s still a little tricky to get right because, if inexperienced, the blood samples can get contaminated with sweat or other impurities and can then affect the final analysis.

It’s also, still, quite expensive at a few dollars per measurement so it won’t find it’s way into the amateur levels just yet.

However, for advanced and elite athletes, this can be a great way to asses improvement and set up their training regime for optimal performance.