[CoachCorner] How I Prescribe Training: Training Types
Intensities, zones and thresholds
CoachCorner is a series of blogs in which I share information that is mostly relevant to the runners I coach. Regardless, feel free to comment below should you have any questions, and I will follow up. Thank you.
When prescribing individual training days, I assign a training type (e.g. recovery run, tempo run, etc.) and associated intensity using the rate of perceived exertion (RPE, which is simply a way to measure how hard an exercise feels to you, from 1 to 10). The training type typically has a clear association with what we call training zones, i.e. ranges of exercise intensities that should result in certain physiological responses (e.g. a recovery run is zone 1 for a well-trained athlete).
In this blog, I provide an overview of training types and associated RPEs, together with zones and race-specific intensities to address different physiological systems and training goals, so that you have a good overview of how I prescribe training and how it all links together.
While we could spend our entire lives discussing zones, thresholds, if they exist, where they stand with respect to each other, what’s the most appropriate name to give them, etc. - this is not the point of this blog, which simply aims to define a common language so that training can be carried out as originally prescribed.
In another blog, I will cover higher-level periodization, but here, we focus only on individual workouts, regardless of the training phase.
Zones and thresholds
I use a 5-zone system, where Z3 is the only zone that is actually demarcated by what we consider somewhat measurable thresholds (the first and second lactate thresholds, LT1 and LT2, or the first and second ventilatory thresholds, VT1 and VT2). Thus, we have 5 zones and 2 thresholds.
When I talk about the aerobic threshold, I refer to LT1 (or similarly, VT1), i.e. the top end of zone 2, where we can see the first small rise in lactate during an incremental test. Typically, training up to the aerobic threshold is considered easy from a cardiovascular point of view (we will see that for well-developed athletes, training near the aerobic threshold is quite demanding from a metabolic and mechanical point of view).
When I talk about threshold workouts, I refer to LT2 (or similarly, VT2 or critical speed or power or maximum lactate steady state or the anaerobic threshold), i.e. the limit between zone 3 and 4. I define this as the intensity that you can sustain for a 1-hour race (e.g. half marathon pace for an elite athlete, or 10km pace for a novice athlete), and often call it the second threshold. It is often easier to capture this with workout data and mathematical modeling (e.g. critical pace or speed) than with actual lactate data.
In the absence of laboratory tests, we can use perceived exertion and training data to estimate these thresholds and define training zones (lab data is often not necessary, especially when collected too sporadically and in unrealistic conditions).
While prescription will be based on RPE, using RPE effectively is not an innate quality of most athletes. As such, we might use heart rate, lactate or other data to fine-tune the process - depending on your preference and the tools you have available.
Training types
I use the following training types to prescribe training days, which are detailed in the next section:
Easy, Z1, RPE 1-3
Endurance, Z2, RPE 3-5
Tempo, Z3, RPE 6-7
Threshold, Z4, RPE 8
VO2max, Z5, RPE 9-10
Neuromuscular training
Overview
Here is a graphical representation of zones, thresholds and associated RPEs:
Detailed breakdown of zones
1. Easy (Zone 1)
RPE: 1–3, light intensity, relaxed breathing
Purpose and Training Effect: Easy running to develop aerobic capacity without fatigue accumulation. Builds aerobic base (enhances mitochondrial and capillary density), and supports recovery.
Metabolic Considerations: Quite a bit below the aerobic threshold. Primarily uses slow-twitch muscle fibers, relying heavily on fat oxidation. Minimal carbohydrate use.
Typical Structure:
Continuous efforts: 30 minutes to several hours.
Used for recovery, warm-ups, or cool-downs.
Athlete Level:
For advanced athletes, Zone 1 is the bulk of easy runs, as Zone 2 becomes more challenging due to an improved aerobic threshold, and therefore will be a smaller part of training.
For novice runners, Zone 1 might include walking or very slow jogging and typically all low-intensity training is done in zone 2.
Alternative names you might find elsewhere: Recovery, Easy Jogging, Relaxed Running.
2. Endurance (Zone 2)
RPE: 4–5, light to moderate intensity, more elaborated breathing, can still hold a conversation
Purpose and Training Effect: Steady-state running to build endurance and aerobic capacity. Improves aerobic efficiency, fat utilization, and fatigue resistance.
Metabolic Considerations:
Up to your aerobic threshold, which defines the upper limit of this zone. Uses slow-twitch fibers and starts recruiting fast-twitch fibers. Energy is a mix of fat and carbohydrates, with fat oxidation dominant.
Typical Structure:
Continuous efforts: 60–120 minutes.
Athlete Level:
For advanced athletes, Zone 2 is harder due to a higher aerobic threshold and might feel closer to RPE 5.
For novice runners, Zone 2 can feel like a light jog, with RPE around 3 or 4, and may even require walking to stay within the zone.
Alternative names you might find elsewhere: Steady State, Long Slow Distance (LSD), Aerobic Running, Base Building, Zone 2 training.
3. Tempo (Zone 3)
RPE: 6–7, moderately hard, breathing more heavily
Purpose and Training Effect: Above your aerobic threshold, but below the second threshold or critical pace. Race-specific training, typically at marathon pace for advanced runners. Improves lactate clearance, running economy, and sustained effort at race intensity.
Metabolic Considerations:
Relies more on fast-twitch fibers, with a higher reliance on carbohydrates for energy. Lactate production increases but is efficiently cleared.
Typical Structure:
Continuous efforts: 20–90 minutes at tempo pace.
Tempo intervals: 2–3 x 15–40 minutes with short recoveries (1–3 minutes).
Athlete Level:
For advanced runners, Zone 3 aligns with marathon pace and is just below the second threshold.
For novice runners, marathon pace might fall within Zone 2, requiring a different training approach.
Alternative names you might find elsewhere: Marathon Pace, Tempo Run, Lactate Threshold.
4. Threshold (Zone 4)
RPE: 8, vigorous activity, heavy breathing
Purpose and Training Effect: Training at “1-hour race intensity” to improve your ability to sustain a high-intensity effort for longer. Improves fatigue resistance, and boosts high-intensity endurance.
Metabolic Considerations:
At or slightly above the second threshold. Heavy recruitment of fast-twitch fibers, relying almost exclusively on carbohydrates. Lactate production is high.
Typical Structure:
Intervals: 2–6 x 5–15 minutes at threshold intensity, with short recovery (e.g. 2-3 minutes).
Progressive runs: Start slightly below threshold, finish slightly above.
Athlete Level:
Advanced athletes use precise threshold work to optimize performance at their limits.
Novice runners might find this zone less defined and overlap with Tempo efforts.
Alternative names you might find elsewhere: Lactate Threshold, Anaerobic Threshold, Sweet Spot, Submaximal Effort, Critical Pace, Critical Speed.
5. VO2max (Zone 5)
RPE: 9–10, feels very hard, can only maintain this intensity for a short time
Purpose and Training Effect: Short intervals to maximize aerobic capacity and oxygen utilization. Improves VO2max, oxygen delivery, and anaerobic capacity.
Metabolic Considerations:
Above the second threshold, near your limit. High recruitment of fast-twitch fibers, reliance on carbohydrates.
Typical Structure:
Intervals: 4–8 x 2–4 minutes at VO2max pace, with recovery equal to or slightly longer than the effort (2–5 minutes).
Hill repeats or sprints: 6–10 x 10–20 seconds all-out with full recovery.
Athlete Level:
Advanced athletes are unlikely to improve VO2max, but training can be useful in terms of race specificity for short events, or to improve fast twitch muscle fibers.
Novice athletes should focus on effort and will see larger increases in VO2max.
Alternative names you might find elsewhere: VO2max Intervals, Hard Intervals, High-Intensity Training.
Neuromuscular training
In addition to the training types and zones described above, sometimes you will see mention of neuromuscular training. While not part of my “zone framework”, neuromuscular training plays a critical role in enhancing running efficiency, coordination, and power.
Purpose and Training Effect: Develop fast-twitch muscle fibers, improve running mechanics, and boost maximal force production. Improves neuromuscular coordination, running economy, and power with limited cardiovascular impact due to the short duration.
Effort Level: All-out sprints or near-maximal efforts. Focus on good running form.
Metabolic Considerations: Primarily anaerobic, with minimal energy contribution from fat or carbs due to the short duration of efforts.
Typical Structure:
Short sprints (10–20 seconds) or strides (15–30 seconds).
Complete recovery between efforts (3–5 minutes).
Performed on flat ground or uphill.
Alternative Names: Strides, hill sprints, explosive sprints, speed drills.
That is all in terms of training types and intensities.
In your training plan you will typically find training days prefixed by the following structure:
[PHASE:MIC:WEEK:TRAININGTYPE] WORKOUT
Where PHASE is the training phase, not discussed in this blog (e.g. Base, Specific, etc.). MIC is the microcycle in the current phase, only present for athletes using a 2-week microcycle instead of a 1-week microcycle. WEEK is the week number in the current microcycle and TRAININGTYPE is the training type as per this blog post (e.g. recovery, tempo, etc.). After this prefix, you will find a detailed description of the workout. Here are a few examples:
[BASE:M1:W1:ENDURANCE] 60’ high-end Z2, just below the aerobic threshold
[BASE:M1:W1:EASY] 60’ easy, RPE 2
[SPECIFIC:M1:W1:TEMPO] 20’ warmup, 3 x 20’ tempo (RPE 7), 2’ recovery, 10’ cooldown
Here is an example week, week 1 of the second microcycle (this athlete uses a 3-week microcycle) during the Base (or Generic) phase:
We will also associate race-paces to these intensities, especially in the more Specific phase of training, see an example below for a well-trained athlete:
That’s all for Training Types and Intensities.
The aim of this blog was to define a common language so that training can be carried out as originally prescribed - in case of any doubts, please drop me a line, thanks!
Marco holds a PhD cum laude in applied machine learning, a M.Sc. cum laude in computer science engineering, and a M.Sc. cum laude in human movement sciences and high-performance coaching.
He has published more than 50 papers and patents at the intersection between physiology, health, technology, and human performance.
He is co-founder of HRV4Training, advisor at Oura, guest lecturer at VU Amsterdam, and editor for IEEE Pervasive Computing Magazine. He loves running.
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