Athletes, coaches, and support personnel are increasingly interested in designing training programs based on scientific facts to be able to reach top performance in our respective sports. Training loads are an important part of the winning formula.
So why is it so important to measure load?
Monitoring training load can provide a scientific explanation for changes in performance. It also could give us personal benchmarks to ensure we are not undertraining or overtraining. Overtraining happens when you perform more training than your body can recover from. A less severe variation of overtraining is referred to as overreaching, which you can recover from in a few days, while more severe overtraining can take weeks, or months of recovery and may lead into injuries if not managed properly. On the other side of the equation, if we undertrain our athletes, then we face other issues, like lack of progression, which takes us away from our competitiveness goals. Hence we need to find the right training load for peak performance and progression.
By monitoring training load we can determine whether an athlete is leveraging a training program and whether this training program is within the thresholds to minimise risk of injury. In order to gain an understanding of the training load and its effect on an athlete, there are plenty of ways of measuring load. If we have access to the right equipment and software we should be able to use power output measuring devices, time-motion analysis, internal load unit measures, including perception of effort, heart rate, level of lactic acid in the blood, and training impulse to get load measurements. Other monitoring tools used by high-performance programs include heart rate recovery, neuromuscular function, biochemical assessments, psychomotor speed, and measurements of sleep quality and quantity among others.
If we don't have the level of resources to fund the equipment and the software we can still go a long way by measuring survey-based metrics such as ate of Perceived Exertion (RPE), because it doesn't require the use of expensive equipment. Even if the funds are available, RPE is a fairly reliable way of measuring training load.
The Rate of Perceived Exertion Scale was developed by Professor Gunnar Borg at Stockholm University. It is a practical chart you can use to estimate how hard you are exerting your body during a training session.
To explain the Borg scale, at the bottom of the scale, or zero, no exertion takes place; at the top of the scale, or 10, maximum effort is taking place. There is a variation of this scale that utilises a 6-20 scale (same principles).
|RPE Scale||Level of Exertion|
|0||No exertion at all|
Does it really work?
The measurement of exertion, it is a very individual thing, hence could vary among people doing the same activity at the same pace. For example, if you are going for a run with an excercise partner who is not in as good shape as you, he or she may perceive a higher level of exertion than you. This is OK, but how accurately can we measure exertion if all we do is ask how hard we perceive the training session we just had?
The whole RPE methodology works based on the fact that Borg found a high correlation between the actual heart rate and the rated perceived exertion plus "10" times "10", during physical activity. Hence this methodology provides a fairly good indication of load.
To address the subjectivity of the test, you can then combine it with the talk test and your heart rate measurement (which you can measure objectively by checking your pulse) and this should give you a fairly accurate perception of your exertion level. You could use this as a cross-check to see if you are accurately measuring your perceived exertion levels. Simple!
The Talk Test
You can determine your level of physical activity by how many words you can say when talking while excercising. If you are at a high vigorous level, you should only be able to say a few words at at time. If the level of exertion is quite low then you are able to say more words more freely.
|RPE Scale||Talk Test Notes|
|1–2||Very easy; you can talk with no effort|
|3||Easy; you can talk with very little effort|
|4||Moderately easy; you can talk comfortably with little effort|
|5||Moderate; talking requires some effort|
|6||Moderately hard; talking requires quite a bit of effort|
|7||Difficult; talking requires a lot of effort|
|8||Very difficult; talking requires maximum effort|
|9-10||Peak effort; cannot talk|
Target Heart Rate
Hence by knowing your target rate, then you can work backwards in terms of the exertion level you want to have to achieve specific goals. When training, you should stay in the 80% to 90% of your maximum heart rate. To find your maximum heart rate, take 220 minus your age. Then multiply that by 80% or 90%. This is your target heart rate.