Tolerance intervals are interval training with high intensity and relatively short intervals. The high intensity challenges the anaerobic energy systems, and with moderate rest, the aerobic systems also work hard.
Unfamiliar with aerobic and anaerobic concepts? Read more here.
A Demanding Interval Form
These intervals are often used by 5000m elite runners in the final training phase before competitions. It is a very demanding form of interval training, and probably not advisable year-round.
The name “tolerance intervals” comes from the requirement to “tolerate” high levels of fatigue substances in the body. With high intensity and moderate rest, you accumulate fatigue substances with each interval, not clearing them completely before the next.
Short and Intense
The typical length of intervals in this category is about 150-600m, and the pace is around 800-1500m pace (if known). Almost sprinting! The rest periods are longer than interval lengths – often 1:2, e.g., 25-second interval with 50-second rest.
Sometimes, it makes sense to discuss both rest and set rest for this type. It means performing a certain number of intervals with a given rest (a set), then taking a set rest before starting the next set.
For example, 2 x (8 x 25 sec) – 2 sets of 8 x 25-second intervals with 50-second rest and a 2-minute set rest.
In the above, you should:
- Set 1: Run 8 x 25 seconds with 50-second rest between each interval.
- Take a 2-minute set rest.
- Set 2: Run 8 x 25 seconds with 50-second rest.
Examples of Tolerance Intervals
- 16 x 30-second intervals with 1-minute rest
- 2 x (10 x 400m) with 2-minute rest and a 5-minute set rest
- 20 x 150m with 150m walk/slow jog
