The principle behind it: intense load triggers short-term adaptations that the body implements during recovery – following the principle of supercompensation. The body is challenged to increase its maximum oxygen uptake (VO2max), tolerate more lactate and raise its threshold power (FTP).
The principle behind it: intense load triggers short-term adaptations that the body implements during recovery – following the principle of supercompensation. The body is challenged to increase its maximum oxygen uptake (VO2max), tolerate more lactate and raise its threshold power (FTP).
The key lever is the duration of the intervals – it determines which physiological system you train:
| Interval type | Duration | Training goal |
|---|---|---|
| Short intervals | 30–60 seconds | Sprint ability, anaerobic capacity |
| Medium intervals | 3–8 minutes | VO2max, lactate tolerance |
| Long intervals | 10–20 minutes | Threshold power |
| Sweet-spot training | 15–30 min (85–95 % threshold) | Efficient FTP increase |
The 4 golden rules for effective intervals
- 1. Duration determines the goal. 20–60 seconds train anaerobic capacity, 2–5 minutes train VO2max and 8–30 minutes train the lactate threshold. If you want everything at once, you end up training nothing properly.
- 2. First increase the number, then the duration. With hard VO2max intervals, keep a fixed duration and increase the number of repetitions first. Only once you manage 15–20 minutes of total load in the target zone should you extend the individual intervals.
- 3. There is a time limit. At moderate fitness, a maximum of 15–20 minutes of pure time-in-intensity per session makes sense. Anything beyond brings little more, but significantly more fatigue.
- 4. Adapt to your fitness. Your training level, your strengths and the demands of your target race decide the right combination – not the latest pro gear.
Popular interval formats for practice
- 30/30 intervals: 30 seconds high, steady load, 30 seconds easy spinning – for example 3 × 10 × 30/30. Ideal for getting started with intense training.
- 5 × 5 minutes: five minutes in zone 4 (80–90 % max. HR), with 5 minutes easy riding in between – the classic for improving VO2max.
- Sweet spot: 2–4 × 15–30 minutes at 85–95 % of threshold power – demanding, but manageable and extremely effective.
Important: always ride intervals evenly – not the first one all-out and the rest only at 280 watts. And warm up thoroughly before every session!
The 3 most common mistakes
- Too many intervals too early – base endurance suffers and the risk of injury and overtraining rises.
- The same programme every week – without variation, performance stagnates.
- Neglecting recovery – intervals are only half the performance; recovery is the other half.
Conclusion
Interval training is the fastest tool to get faster in a targeted way – but it is not a cure-all and not everyday training. Whoever first builds a solid aerobic base, then schedules 1–2 targeted interval sessions per week during competition preparation and recovers sufficiently will get the greatest benefit from it.
So: first the base, then the intervals – and soon you will feel the difference on the road.
Published on August 5, 2026 · Prothletics Flow Fitness Guide