Hour of power

Hour-of-powerAim of session

Enabling the rider to become accustomed to riding for extended periods of time at their sustainable power and develop the ability to balance lactate production / clearance


Session description

WARM UP: Take 15 mins to hit the power you can hold for ~ one hour (your second threshold power / “FTP” or 25 mile pace), not included in session duration

MAIN SET: Once at the sustainable power, hold for the session duration. Every 2 minutes, you can either get out of the saddle for 10s, or alternatively, change to a smaller gear for 10s, letting power drop off. As the name suggests, your aim is to build to a whole hour!

COOL DOWN: add 10 mins of spinning onto session duration if required


The second lactate threshold (also referred to as “functional threshold power”) is a key marker of endurance performance, and sits at the intensity riders would race over 25 miles or hour long criteriums. The threshold point is the upper intensity for balancing blood lactate – working just below it is a hard, but sustainable power which the rider can hold as long as carbohydrate needs are met; yet working just a little above would bring exercise to an end within 30 to 40 minutes – because lactic acid in the muscles and other metabolites would prevent further muscle contraction.

Application for the Rider

Sitting on the balance point of lactate production / clearance is one of the best ways to cause the body to adapt – but, unless the rider is incredibly motivated, to do this in training is extremely difficult. In addition, doing this too often would endanger too high a training stress. Much better is the approach of achieving sufficient exercise stress yet can be repeated frequently within a training block – enter the “Hour of Power”. The majority of the time is spent ON the second threshold power; but with every 2 minutes, the short break is enough a) to break the session down mentally, avoiding the relentlessness nature of this work and b) offset fatigue by changing the muscle recruitment momentarily – this should give the lactate clearance mechanisms a little ‘breathing space’: the training overload comes by increasing the duration of the time managed at second threshold intensity.

Practicalities and tips!

  • Be aware that the session aim is TIME at this balance point intensity. Therefore, pick the intensity of the ride carefully: too ambitious will soon lead to fatigue, as just 1W above a sustainable load will cause fatigue to come very quickly
  • Take into consideration that your race power is just that –achieved under race conditions that might not be attainable in training: we are all more motivated in racing environments, and more likely to be physically fresher than in a training block. Taking into consideration to first bullet point above, you might be better riding 10W below race power and completing more time. You can always raise the challenge next time around!
  • Because this is a race pace session, it is normally used within the race build training cycle. Therefore, consider if it is possible doing this session on your race bike in your racing position – especially important for time trial specialists.
  • Working in zone 4 is hard – be prepared to have to bite the bullet, and give yourself every chance of succeeding by preparing plenty of fluids and energy drinks (especially if tackling on the turbo trainer)

Evaluation of the session

  • Did you complete the target duration? If yes, consider if the next step is to increase time (probably the option if session duration is <1 hour) or intensity (probably the case if you have now reached an hour)
  • If you didn’t complete the specified time, what caused you to stop?
  •  What did you heart rate response look like? Was it continually rising, or had you reached a visible steady state? How similar was the heart rate to your racing heart rate?
More in this category: « Power pyramid Redline »