Assessing Effort
Wednesday, January 20, 2010 at 10:00AM In theory, performance in many endurance activities seems cut and dry. Lets keep it simple and use the example of a 5km runner. His performance is how fast he can run 5km. In training, he will get an idea of performance from splits over a known distance, eg. a track session. But there are many things impacting on performance. The figure below shows the standard Performance = Fitness - Fatigue which obviously has a large impact on training and racing performance.
So while fatigue is a factor that causes performance to continually fluctuate, what about effort, or exertion? Lets say our 5km runner has a PB of 18min, and he runs 18:20 but says I could have run harder. What does this mean and how much of an impact does this submaximal effort have on performance.
Another good example of the importance of effort is the standard race situation where the athlete finds that extra few percent in the competitive environment that they don't usually display in training.
In many ways effort may be measured by intensity. For example, you are running at a heart rate of 180; this means your intensity is high and your effort is obviously high too. But what about when you are fatigued, so your heart rate is suppressed. You may still be running at a high level of effort but your HR is lower and your speed is slower. The opposite also holds true.
But can effort actually be measured? Most of us don't bother. We look at speed and we look at intensity (HR), but maybe we should actually be using the old school method of a Rating of Perceived Exertion (RPE). The revised RPE scale uses a rating of 1-10 to determine how hard an athlete is working. This is based on the athletes perception of effort. On many occasions it will complement HR but by using this in addition to HR, we can actually tease out some additional information.
Lets look at an example. On Sunday I was out for my usual long run, it felt pretty easy but my respiratory rate was high so I glanced down at my HR to see 147. This seemed rather high for the effort and I would have expected it to be about 10bpm lower. Was I dehydrated? It wasn't that hot and I thought I had drunk plenty of water the night before. So when I got home, I weighed myself to find I was 1kg less than after most runs. I was definitely dehydrated and the discrepancy between HR and RPE had allowed me to know that something wasn't right.
So I don't keep rambling on for many more pages, lets reassess what this means. Most of us get hooked on knowing our speed and HR as they provide obvious benefits; and if you arn't a user of speed and HR in training, it is definitely worth considering. But do many of us actually monitor our effort? It is free, it is easy and it is extremely valuable. If you don't monitor your effort regularly, I suggest covering up your HR for a few runs and force yourself to ask 'how hard am I going'? While it might seem simple, plenty of athletes that use HR get fixated on it and forget to listen to their body.
Additionally, if you are a coach, I would recommend asking your athletes their RPE in all key training session. Jot this down and monitor it over time as it may provide you with a valuable insight into your athletes.
Reader Comments (2)
Perceived exertion is a great tool. Temperature, humidity, hydration, mental fatigue, time of day, blood sugar levels, yesterdays session, who you are training with etc etc all impact on heart rate. Kenyans seem to use 'how they feel' almost exclusively, probably a very good approach!
Good point about the Kenyans Corey. As I mentioned in the blog, I am a big fan of HR monitors but from my experience, some athletes get too caught up on looking at HR and forget to listen to their body. They lose the ability to understand their effort and that can impact on pacing in a race, race performance and training. You also make a good point about things such as temperature. Thanks for your comments.