The key for accurate Power Meter readings is Placement of gauges, Quality of gauges and Even temperature of measured material, so realistically a left crank Power Meter will work equally as well as a one that is integral to peddles or spider. Professional riders are more likely to have an integral Power Meter, but they are mostly price-prohibitive for the amateur; although the obvious advantage with pedals is that they can be swapped to different bikes.


Left crank units

So if you choose the Left crank unit, and we feel you should very much include PowerSense in your research here, as we are the most affordable, with absolutely no loss of quality as they are British made, and we’ll talk to you if you need any help. Ok, consider that the sales pitch done 😉


What you need to do when you get the unit is to fit it and ride with it. Just enjoy for a week’s worth of rides and download the results to TrainingPeaks or any other bit of training software – Strava works too, and take a look. You’ll be able to see when you have been working hard or just spinning, and the variations in between. 


This means you are now you’re well on your way to understanding power zones; they are literally the above. Where the science comes in, is calculating your Functional Threshold Power (FTP) which is also referred to as Lactate Threshold (LT), as the zones are created relative to this. The easiest way to explain, for most amateur athletes is by saying ‘it’s the switch from aerobic to anaerobic’, as this is when the body goes over the threshold and the  ‘burn’ begins, that we can only sustain for a short period. The body will require stopping or slowing to clear waste products created by exercise.


 Hopefully knowing this, the Coggans table below is going to start to make sense of your training.




% of FTP



Active recovery


Minimal effort




All day pace




Intensity or fartlek workout, requiring concentration to maintain alone


Lactic Threshold


Conversation is difficult due to the intensity of breathing.


VO2 Max


Jagged breathing. Do not attempt on consecutive days. 3-8 minutes.


Anaerobic capacity


30 seconds to 3 minutes. Conversation is impossible.


Neuromuscular power


Very short, high-intensity efforts eg. standing starts.


Working out your FTP

To work out your FTP you’ll need a field test, which is usually better performed outside. Find a flattish course, any inclines should be less than 5%, and try to avoid traffic lights or excessive traffic.


Hunter Allen’s FTP test includes a 15 minute warm-up which includes 3 x 1 minute peddling drills. This warm-up should not take energy from the 20 minute test itself. The 20 minute test should be done as a time trial, as fast as you can, but to still last the full 20 minutes. Use the Average power reading, from the test, less 5%. Using TrainingPeaks you can now create your training zones. For example your avg power at the end of the test was 210w …so…


210 * 0.95 (to minus 5%) = 199.5w  ← that’s your current FTP


The Benefits

Now you have the Power zones you can train accurately, as you can work in a zone regardless of the weather, wind, course profile or fatigue. You will notice how ‘jumpy’ the power output tends to be, but that is from external changing resistance, like a gust of wind. You can now create structured training routines, so improvement is virtually guaranteed. It’s recommended that you work out your FTP every six weeks, for the beginner, improving the FTP is certainly a big step in the right direction.