Cycling Knowledge Base Running Triathlon

Maximize Your Performance with Effective Interval Training

Discover how interval training enhances your performance and why 2PEAK’s approach helps you achieve your training goals and push your limits.

What is interval training and why is it important?

Interval training combines short, high-intensity periods of exertion with recovery periods and plays a central role in the training routine of athletes to maximize performance. This training method is essential for both runners and cyclists. By varying the intensity and duration of the exertion phases, specific energy systems of the body are targeted and optimized. This leads to various physiological adaptations, including:

  1. Improved Cardiovascular Efficiency: The heart becomes more efficient in pumping blood, resulting in a higher stroke volume and improved oxygen delivery to the muscles. This enables sustaining higher performance over longer periods.
  2. Increased VO2max: The maximum oxygen uptake improves. This means that the body is able to absorb and utilize more oxygen, allowing for more efficient energy production during exercise.
  3. Enhanced Lactate Tolerance: Through regular interval training, the body becomes more efficient at handling lactate accumulation. This allows athletes to sustain more intense efforts for longer durations without experiencing fatigue.
  4. Optimization of Energy Supply: The body improves its ability to mobilize and utilize energy from various sources, including more efficient utilization of fats and carbohydrates.
  5. Improvement of Muscle Economy: Interval training promotes the development of faster-reacting and more efficient muscle fibers, leading to improved muscle economy.
  6. Increase in Muscle Strength and Endurance: The intense muscle engagement during exertion phases stimulates muscle growth and strength development, resulting in improved muscle strength and endurance.
  7. Adaptation of the Nervous System: Improved coordination between the nervous system and muscles leads to more efficient movement execution and a reduction in fatigue during high-intensity exertions.

The regular incorporation of interval training into the training plan promotes rapid and effective adaptation of the body, allowing athletes to push their performance limits and achieve their personal goals.

Intervals with 2PEAK

An interval is technically considered as such only when there are at least two similar exertions with corresponding recovery periods in between. 2PEAK makes an exception here by counting even individual intervals, as long as they comply with the following rules.

Minimum Requirements for Interval Training:

Minimum Effort

  • Running and Cycling: The interval must consistently be above the threshold of your training zone. It is important that your training zones are accurately defined and regularly updated. A tolerance of approximately 5% is built into each zone, allowing for minor deviations. Note that efforts in Zone 5 (peak range) cannot be precisely monitored via heart rate, and sprints (under 10 seconds) are difficult for runners to recognize based on pace. Power measurement, however, always works.

Minimum Duration

  • Running and Cycling: An interval must last a certain amount of time necessary to stimulate the intended energy source. Depending on the zone, this varies from a minimum of 6 seconds for Z5_high (sprints) to a minimum of 6 minutes for Z3 (medium to high intensity).

Minimum Consistency

  • Specific to Cycling: You could try to achieve a minimum of, for example, 300 watts by alternately exerting 10 seconds at 150 watts and then 10 seconds at 450 watts. Although this is certainly strenuous, it does not stimulate the same energy source as the continuous production of exactly 300 watts over a longer period. Excessive variation falls outside the tolerance.

Maximum Outliers

  • Running and Cycling: Minor interruptions, such as a loss of power in a curve while cycling or a brief GPS loss while running, do not affect the validity of your interval as long as they last only a few seconds. However, if the interruption lasts too long to be considered an outlier, the interval is interrupted and may be declared invalid.

These criteria are crucial for conducting interval training, as they not only ensure the quality and effectiveness of training sessions but also enable accurate recording and analysis through tools like 2PEAK. By adhering to these guidelines, you can ensure that your intervals bring maximum benefits and are correctly accounted for in your training.


Interval training is essential for athletes looking to improve their performance. By strategically combining intense exertions with recovery periods, it promotes significant physiological adaptations and maximizes performance. The precise criteria set by 2PEAK for interval training ensure that each training session effectively contributes to performance improvement. Integrating this method into the training routine allows athletes to expand their limits and continually improve, both physically and mentally. Interval training is thus a key tool on the path to personal best performances and beyond.


Create with 2PEAK a triathlon, cycling, and running training plan based on artificial intelligence that adapts to your performance after each workout. Download the app and start revolutionizing your training.