BuildAim of Session

To build on the base level of endurance by gradually stepping up the intensity and visiting zone 4


Session description

WARM UP: No warm-up required, session duration is total session time
MAIN SET: Start with 1 hour zone 2 / 3 border, thereafter, every 15 mins, increase intensity by 5 bpm until end of target ride time
COOL DOWN: add 10 mins of spinning onto session duration if required


Similar to the ‘Brisk’ session, this training session is again focused on the physiological adaptations that create a better base endurance level (increases in plasma volume, capillary and mitochondria number, muscle glycogen storage). However, after a period of riding at a steady-state pace, this session requires an increase in intensity every 15-minutes. In the first 5-minutes of these 15-minute blocks, the body will respond to the increased intensity by increasing heart rate, stroke volume and ventilation. After approximately 5-minutes a steady-state will be reached where heart rate, ventilation and exercise metabolism will level off and remain stable. The subsequent increase in intensity every 15-minutes provides new stress and allows the body to learn to cope when a small change in intensity is required. The continuing stress provided in this session ensures the body is continually learning to adapt to changes in exercise intensity. This can provide beneficial adaptations in both the physiological mechanics of exercise and the neurological messaging that initiates the physiological responses to increase exercise intensity.

Application for the Rider

This session is an ideal way to stretch the body gradually – just as it reaches a new steady state, we take it to a new level and the systems have to readjust. As the rider moves up through low to mid, mid to high zone 3, and into the bottom reaches of zone 4, the systems involved in carbohydrate supply and lactate production are elevated. The body therefore has to work on improving oxygen supply to reduce lactate concentrations in the blood. You will often see this session when the training cycle is about to enter a zone 4 emphasis.

In addition, this session is great for improving pace judgement. No race is ever ridden over one continued steady state-pace. Gradually changing the intensity during a training session like this allows the body to respond more quickly to changes in intensity that might occur during any race (e.g. when the road gradient is increased). A rider who can quickly and comfortably adapt to these changes will be well equipped perform well over long distances and may be able to squeeze out a little bit more than their rivals over a long period of time.

Practicalities and tips!

  • Choose carefully a route that will allow the session structure to be applied. The most successful rides are those where the ‘build’ part in the latter stages of the session can be controlled – a 5bpm rise in heart rate is a very fine adjustment, especially when trying to keep cadence nice and fluid.
  • For skill development, this session is best done on the road rather than a turbo
  • Mark each 15 minute block off using the lap or interval button on your cycle computer – this make subsequent analysis far easier.
  • Know a suitable starting power, but from then on we suggest you control the session by heart rate: simply as the aim of the session is to ride with increasing ‘stress’ – and heart rate is our measure of stress (how to body is coping with the power delivered). This also allows the session to be progressed naturally rather than forcing a stepwise power target and imparting too big a jump in stress outcome
  • Keep drinking and taking on carbohydrate – by the end of the session you will be in the “carbohydrate shredding” zone 4! Most unsuccessful Build sessions are because of a lack of decent fuel supply

Evaluation of the session

  • Take a look at each 15 minute block – how well did you control the heart rate increments?
  • What were the resulting power increments? Is there a similar increase in power between each 15 minute block?
  • How easy was it to increase the heart rate each block?
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