Sweetspot bursts

sweetspot-burstsAim of Session

A more advanced version of the sweetspot workout aiming to improve performance at second threshold.



Session description

WARM UP: Ensure 15 mins warm up before starting the efforts, worth considering having this contain 5 mins in low end zone 3 to make sure the engine is ready, include this time within the session duration
MAIN SET: Perform 2 x 20 mins blocks of effort in the upper end of zone 3 i.e. approx 90% of your 25 mile power (or FTP). THIS IS NOT A ZONE 4 EFFORT, but more controlled. During each block, every 4 minutes raise the power to 120% of 25 mile power for ~20s. 10 mins of easy pedalling in between each block.
COOL DOWN: add 10 mins of spinning onto session duration if required, not included in session duration


The physiology behind this session is not disimilar to the standard sweetspot session. The aim is to stress your lactate clearance mechanisms and hydrogen ion buffering - the short high intensity bursts will increase this stress. Think of a bath tub - riding at sweetspot has you riding with a water level (think lactate) just under the brim; with each burst, you fire water from a hose (more lactate) into the bath tub. Your body has to adapt to make the plug hole bigger (lactate clearance mechanisms) in order to prevent the bath tub overfilling.  Also the higher intensity bursts require the recruitment of a greater proportion of fast twitch fibres, forcing them to adapt to contracting in a more acidic environment. These fibres will be essential when you begin working at higher intensities.

Application for the Rider

This session provides another bridge between endurance base building and race specific workouts in zone 4 and above. Sweetspot bursts are an ideal way to step towards sessions like 'redlining' in a race build block. Most riders find sustained training in zone 4 to be quite challenging - a solid foundation of workouts of this sort can make the progression much smoother. This session can also be useful for riders preparing for bunch racing. By including bursts of high intensity within your sweetspot sessions the stop, start nature of racing on the road and track can be replicated.

Practicalities and tips!

Everything that applies to the other sweetspot sessions also applies here. For the higher intensity bursts you may wish to experiment with increasing cadence in the same gear or riding out of the saddle for the ~20s period.

Evaluation of the session

  • First make the same evaluation as for the standard sweetspot sesison
  • In addition, check that you completed each burst at the correct time and intensity
  • Note your heart rate reponse following each burst - does your heart rate recover to the level expected for sweetspot intensity?


More in this category: « Sweetspot Sweetspot cadence »