ASLAK SWIM - coaching

This is one of the training structures I have used the most for high-quality work. The idea is simple:

combine high aerobic / threshold swimming with aerobic effect / VO₂-max work in the same set. Instead of going straight into very fast swimming, the set gradually builds:

High aerobic → Threshold → VO₂-max / Aerobic effect

Most of the time, I like the send-offs to give slightly more recovery as the speed increases and the repeats get shorter. That way, the body gets warmer, the aerobic system becomes more activated, and I can gradually put more and more pressure on the water. For me, this structure allows my heart rate to hit the right intensities more naturally, while my technique and speed stay connected.

Sometimes I have even experienced that my times get faster when I build into aerobic effect work, instead of starting directly at that pace. The progression helps me find the rhythm, load the system properly, and produce speed with better control. The work-to-rest balance is a big part of why this structure works:

High aerobic 300m: around 90% of the interval is actual work
Threshold 150s: around 80% of the interval is actual work
VO₂-max 100s: around 65% of the interval is actual work

So the faster the swimming gets, the more recovery is built in - even though it definitely does not feel like more recovery.

For me, this is one of the best ways to create quality threshold / VO₂ work: Progressive intensity. Controlled recovery. Rising heart rate. Speed under pressure.

Monday set - a proper lactate tolerance set (Including some VO2 max training as well)

The 4x150 works as a progressive build-up, and between rounds it also functions as lactate clearance, getting the body ready for the real challenge: the 200 best average.

The 200 best average targets both VO₂ max and lactate tolerance. It teaches you to keep producing quality work as lactate accumulates and the stroke starts to fall apart.

For middle-distance swimming, that ability to stay efficient under pressure is a huge part of real race performance.

This Monday set looks simple. It isn’t

The progressive 1-2-3-4-5 structure builds one of the most important qualities in middle- and long-distance swimming: the ability to hold speed and technique as fatigue keeps building.

The early rounds let you establish pace and rhythm, while the later rounds force you to maintain both under increasing fatigue. That is where a lot of the adaptation happens.

This set is great for improving VO₂ max, which you can see from my heart rate in the next picture. On top of that, the intensity creates lactate, while the short recovery between rounds allows for partial clearance without full recovery. That creates a powerful dual stimulus: the body learns not only to tolerate lactate, but also to clear and reuse it efficiently. For middle- and long-distance swimmers, that is critical – not to avoid lactate, but to manage it.

This week’s Monday set is much shorter than the others, which makes it a good fit relatively close to a taper meet, for example 14–21 days out. The set is more specific and is aimed especially at the 800 m, but it can still be beneficially swum slightly faster than the pace you expect to hold at your main meet.

Because the overall volume is lower, the body does not get fatigued in the same way, which also gives you a better opportunity to maintain high quality all the way through. At the same time, it trains your ability to stay stable throughout an entire race, which is absolutely key in the 800 m.

The 8 × 100 function as VO₂ max work with a smaller lactate tolerance component, which also matches well with the values I produced. The final 200 all out pushes the body anaerobically and has a clear purpose: to improve lactate tolerance, which can be especially important at the end of the race, when the pace needs to be maintained or increased under heavy stress.

🟢 Resting: approx. 0.5–1.5 mmol/L
🔵 Normal aerobic work: approx. 1.5–3.0 mmol/L
🟡 Threshold: approx. 3–5 mmol/L
🟠 VO₂ max work: approx. 6–10 mmol/L
🔴 Very high anaerobic load: 12–18+ mmol/L

New Monday set! 30×100m on 1:15, switching between one where the goal is simply to make the start time and one best average. With only 10–20 seconds of rest, there’s no real recovery, keeping the heart rate high throughout the set. The fast reps push intensity above ~90% of max HR, while the controlled ones maintain a high aerobic load and help clear lactate - building a stronger VO₂max/aerobic effect, threshold work, and pace control under fatigue.

Monday set! Long threshold / high aerobic work is a cornerstone in endurance swimming. Training around threshold pace improves the ability to sustain speed, maintain efficiency, and control pacing under fatigue.

Example based on my pace:

10×400 @ ~1:04/100 (~41 min work) Classic threshold training, close to the duration most athletes can sustain at their lactate threshold before fatigue forces a drop in pace or efficiency.

10×800 @ ~1:05/100 (~1h26 work) Extended threshold moving toward strong aerobic endurance.

10×1500 @ ~1:06/100 (~2h45 work) Shifts into high aerobic work. A session of this size requires proper recovery both before and after to maximize adaptation and reduce injury risk.

Just as much a mental training session as a physical one and a great way to occasionally check your form and pacing over long work.