Zone 3 bursts

Aim of Session

All out seated sprints within a zone 3 ride

Session description

WU: Take 10 minutes to get yourself upto zone 3 level, not included in session duration

MS: Lower / mid zone 3 ride, sprinting for 30s every 5 mins. Do 6 sprints per session

CD: 10 min spin, not included in session duration

NB: This session is not to be confused with 'Tempo bursts'


This session will tax the same physiology explained in the other session descriptions in the 'muscular and neural' category. However, there is one fundamental difference - the 'baseline' from which the rider is operating is different. Whilst the other sessions take you from a rest state (low intensity recovery between reps), this one asks the rider to sprint from an already sustained exercise stress i.e. zone 3 riding. If the 6 sprints are completed towards the back end of the ride, the rider will have become lower in their stored glycogen stores. Sprinting from lower carbohydrate availabilty will require a slightly different muscle fibre recruitment pattern as the body attempts to find fibres with some "releasable" energy.

Application for the Rider

It is imperative for race preparation that a rider practices sprints not only when their muscle tissue is fresh, but also when under conditions of fatigue. Sessions like "power sprints" and "hill sprint extra" have a rider sprinting pre / post sustained high intensity work; but not from a raised, continuous intensity that has been accumulated over some time. This latter scenario is where most road racing will take place - for example, the rider that needs to produce a winning sprint having been in a breakaway.

Practicalities and tips!

  • For best effect, place these 6 sprints in the back half of the ride. It makes the sprints tougher, but it augments the training effect, and makes the situation more 'real life' for racing preparation
  • Stay in the saddle for the sprints - this might not emulate the race environment (as you would want to jump away from your competitors with high acceleration!) but it places extra stress on muscle tension development

Evaluation of the session

  • Compare your sprint peak powers and average powers with other sprint session efforts - has the sustained zone 3 work made a difference?
  • How do you peak and average powers compare across the 6 efforts?
  • Have the 6 efforts themselves affected your ability to hold zone 3? Sometimes there are interesting shifts in power to heart rate - imagine the sprints have helped further deplete muscle glycogen stores. You might also find some interesting patterns comparing this session with a flat, zone 3 effort of the same duration?