I’m now four weeks into my training plan for the Leiden Half Marathon. After receiving some feedback on my plan, I came across the concept of tempo blocks in long runs. Last Sunday, I added a tempo block to my long run, but it was completely random and probably not the most effective approach. That’s why I decided to do some research into the benefits of tempo blocks.
What is a tempo block and why use it?
A tempo block is a section within a long run where you run at a pace that is higher than your usual comfortable speed but below maximum effort. The goal is to train both your body and mind to sustain a higher speed over a longer period (either time or distance). This is especially useful when training for a (half) marathon.
How do you determine a tempo block?
There are four ways to structure your tempo block:
- Based on race pace
Depending on your race distance, you integrate a tempo block based on time or distance. For example, if you’re running a 20 km long run in preparation for a half marathon, you could run the last 5 km at your half marathon pace to help your body get used to it. - Based on Heart Rate
For example, a 90-minute long run with 3×10 minutes in zone 3-4, which increases the intensity of part of your workout. - By Perceived Effort (RPE Method)
Use the Rate of Perceived Exertion (RPE) scale from 1-10:
RPE 4-5 (comfortable, can still talk) = easy run
RPE 6-7 (comfortably hard, but sustainable) = tempo blocks
RPE 8-9 (hard effort, talking is difficult) = intervals
Example: 15 km long run with 4×5 min at RPE 7, with 3 min recovery in between. - Progressive Tempo Blocks
You gradually increase your pace per block, for example:
- 5 km easy
- 5 km at marathon pace
- 5 km at half marathon pace
This method also simulates race fatigue.
In past training cycles, I mainly focused on heart rate, but I feel that it hasn’t helped me progress much. I’ve never used the RPE method, but it seems similar to heart rate training. That’s why, for this race, I’m choosing to focus more on specific paces during tempo blocks.
How long should a tempo block be?
There are four ways to determine the length of a tempo block, though they are not scientifically proven. Although there are some for example this one. These methods are based on coaching principles and personal experiences, so it’s best to experiment and find what works for you.
- Based on race distance
10K runners: 5-10 minutes per block (or 1-3 km)
Half marathon runners: 10-20 minutes per block (or 3-6 km)
Marathon runners: 15-30 minutes per block (or 5-10 km)
Example: Half marathon training → 3×12 minutes at half marathon pace in a 16 km run. - Based on total training time
Short runs (30-45 min): 5-10 min tempo block
Medium runs (60-90 min): 10-20 min tempo block
Long runs (>90 min): 15-30 min tempo blocks
Example: Marathon training → 25 km long run with the last 30 minutes at marathon pace. - Based on effort (Heart Rate or RPE)
Short, intense tempo blocks (5-10 min, RPE 7-8, zone 4) → for speed and lactate tolerance
Medium tempo blocks (10-20 min, RPE 6-7, zone 3-4) → ideal for half marathon training
Long tempo blocks (20-30 min, RPE 5-6, zone 3) → best for marathon pace work
Example: 10K training → 12 km total, with 4×8 min tempo (RPE 7) and 2 min recovery. - Progressive tempo blocks
Example: Marathon training → 30 km long run:
10 km easy (zone 2)
10 km marathon pace (zone 3)
5 km half marathon pace (zone 4)
5 km cooldown
Conclusion
After my first experience with tempo blocks and diving into the theory, I’ve come to a few key insights. My initial tempo block of 10 km was likely too long, especially since I’m still in the early phase of my training. Based on my goals and preferences, I’ll experiment with shorter tempo blocks and a structure based on distance rather than time.
Tempo blocks are a valuable addition to long runs—when used correctly. They help your body adjust to a faster pace without needing a full race simulation. For my half marathon training, I’ll incorporate more structured tempo blocks and listen closely to my body to find what works best.