Running plan for improving threshold pace and trail running

This running plan is structured to systematically improve your threshold pace and build specific strength for trail running over a 15-week period. Based on scientific training principles, the program includes a careful balance between high- and low-intensity training, with a particular focus on threshold pace and trail-specific skills.

The program alternates between different types of interval training on Wednesdays, with a focus on both classic intervals and hill intervals to develop both aerobic capacity and specific strength. Long runs on Sundays increase gradually, but non-linearly, to allow recovery between the more demanding sessions. Regular Running Fitness Tests roughly every third Saturday let you measure your progress in threshold pace throughout the training period.

This running program is designed to systematically improve your threshold pace and build specific strength for trail running over a 15-week period. Here are the key components of the program:

• Interval training (Wednesdays): Alternates between different types of intervals to stimulate different physiological adaptations. Hill intervals develop specific strength for trail running, while classic intervals improve running economy and threshold pace.
• Running Fitness Test (roughly every 3rd week): Regular tests to measure progress in threshold pace and running capacity. These tests follow the Coros format and give you concrete data to track improvements over time.
• Long runs (Sundays): Follow a non-linear progression from 15 km up to 24 km, with strategic recovery weeks in weeks 4, 7 and 11. Alternate between trail, road and mixed surfaces to develop all-round skills.
• Easy runs with quality: Include "easy" intervals in Zone 2 and strides to improve running economy without eating into your recovery capacity.
• Technique focus: Dedicated sessions for improving technical skills on the trails, which will improve both efficiency and safety in trail races.
• Periodisation: The program follows a periodised approach across the 15 weeks, with gradual increases in volume and intensity, followed by strategic recovery weeks to ensure enough time for adaptation and reduce the risk of overtraining.
• Variety in interval types: As the program progresses, more advanced interval formats such as pyramid intervals and longer continuous threshold runs are introduced to drive further physiological adaptations and keep you mentally engaged.

To get the most out of this program, it is recommended that you follow the intensity zones closely and listen to your body's signals. Adjust volume or intensity as needed, especially if you notice signs of overtraining or incomplete recovery. Remember that consistency over time is the key to improvement - it is better to complete a little less with good quality than to push the body too hard and risk injury or burnout.

Intensity zones

• Zone 1 (Easy running): 65-75% of maximum heart rate. Conversational pace.
• Zone 2 (Moderate): 75-80% of maximum heart rate. Comfortable but purposeful pace.
• Zone 3 (Threshold): 80-87% of maximum heart rate. Challenging pace that can be sustained for about 1 hour.
• Zone 4 (Interval): 87-92% of maximum heart rate. Hard pace that can be sustained for shorter periods.
• Zone 5 (Maximal): 92-100% of maximum heart rate. Very high intensity for short sprints.

Adjustments

This program can be adjusted based on individual needs and circumstances:

• If you feel exhausted, consider replacing an interval session with an easy run or a rest day.
• For those who want an extra challenge, Saturday's easy runs can be extended by another 10-15 minutes.
• If you are targeting a specific trail race, consider doing more of the long runs on terrain similar to the race.
• Keep an eye on the threshold pace on your Coros watch to track progress and adjust the intensity of the threshold sessions accordingly.
• Use the results from the Running Fitness Test to adjust your training intensities. If your threshold pace improves, the intensity of the interval training should be increased accordingly.
• For runners with limited experience of high training volume, consider reducing the volume of the longest long runs (over 20 km) in weeks 13 and 15.

Session types and terminology

Here is an explanation of the different session types and terms used in the program:

• Running Fitness Test: A standardised test developed by Coros to measure running fitness and threshold pace. The test consists of a warm-up phase, followed by 25 minutes of running just below threshold intensity, then 3 minutes of harder running, and finishes with 3 minutes at maximal effort. Based on the data collected during the test (especially heart rate and speed), your Coros watch calculates your threshold pace and other key training metrics. It is recommended to do the test on a flat, even surface for the most accurate results. Do the test at regular intervals to track progress and adjust your training intensities accordingly.
• Stride/Strides: Short, controlled accelerations of 20-30 seconds where you gradually increase the speed to about 85-90% of maximal effort, hold it for a few seconds, and then gradually slow down. Strides are done on flat or slightly inclined ground with full recovery between each repetition (typically 45-60 seconds of easy walking or jogging). The purpose is to improve running technique, neuromuscular coordination and running economy without accumulating significant fatigue.
• Fartlek: From the Swedish "fart" (speed) and "lek" (play), fartlek is an unstructured form of interval training where you alternate between different intensities based on feel or terrain. In our program, fartlek is used on trails where the intensity varies naturally with the challenges of the terrain: faster on flat sections, harder effort on the uphills, and controlled, technical running on the downhills. It is a playful, intuitive approach to interval training that is especially useful for trail runners.
• Hill intervals: Intense running intervals done uphill. These strengthen specific muscle groups that are crucial for trail running, improve power and efficiency on uphills, and reduce the load on the joints compared with intervals on flat ground. Jog easily back down the hill as recovery between repetitions. Choose hills with a 4-8% gradient for the best training effect.
• Threshold intervals: Intervals run in Zone 3 (about 80-87% of maximum heart rate), which corresponds to the highest intensity you can sustain for an extended period (about 1 hour). These intervals are crucial for improving threshold pace and making the body more efficient at handling and clearing lactate. Typical formats are 4-6 repetitions of 5-8 minutes with short recoveries (1-2 minutes).
• Classic intervals: Traditional intervals over specific distances (e.g. 1000m) run in Zone 4 (87-92% of maximum heart rate). These intervals improve VO2max (maximal oxygen uptake) and anaerobic capacity. They are typically done on a track or flat road with controlled recoveries to ensure consistent effort throughout the session.
• Progressive run/intervals: Sessions where the intensity increases gradually, either throughout the session (progressive run) or for each repetition (progressive intervals). This approach teaches the body to handle increasing load and prepares you for race situations where the pace typically picks up towards the end.
• "Easy" intervals: Short intervals in Zone 2 slotted into otherwise easy runs. These provide a certain training stimulus without significantly affecting recovery. They work as a "lactate vaccine" and help maintain a certain tolerance for intensity even on recovery days.
• Technical running: Sessions with a specific focus on the technical aspects of trail running, such as foot placement, balance, and efficient navigation of uneven ground. These sessions are generally low-intensity (Zone 1) to allow deliberate focus on technique, but often include technically challenging sections that require concentration and specific skills.
• Pyramid intervals: An interval structure where the duration of the work periods first increases gradually and then decreases, often in a symmetrical pattern (e.g. 1-2-3-2-1 min). This variation in work period stimulates different energy systems in a single session and provides both physical and mental variety.
• Hill sprints: Short, explosive uphill accelerations lasting 20-30 seconds. These are done at near-maximal effort (Zone 4-5) and develop anaerobic capacity, strength and power. They are especially useful for trail runners who regularly face steep hills.