If you coach long enough, you start hearing the same phrases over and over. “This is an aerobic day.” “We’re working threshold.” “Today’s race pace.” But when practice is actually happening, it’s not always clear:
Training zones aren’t about turning practice into a lab experiment. They’re about being intentional with intensity, so the work you plan actually produces the adaptation you want.
This article explains how to use training zones in real swim practices, how they connect to swimming physiology, and how to plan training across a week with different intensity distributions, without overcomplicating things.
At the most basic level, training zones describe how hard your swimmers are working.
Each zone stresses the body differently:
Zones aren’t labels you slap on a workout. They’re a way to answer one coaching question:
What adaptation am I trying to get from this set? If you can’t answer that, the zone doesn’t matter.
Most swimmers don’t plateau because they don’t work hard enough. They plateau because everything lives in the middle:
That middle ground feels productive, but over time it leads to:
Training zones help you separate stress:
In swimming, pace matters. Heart Rate is important, but it has limitations. It lags behind effort and can fluctuate with temperature, breathing patterns, hydration, and even stress. That’s why TritonWear anchors training zones to Critical Swim Speed (CSS).
CSS represents the fastest pace a swimmer can sustain without continually accumulating fatigue. Physiologically, it sits close to the aerobic–anaerobic transition.
In coaching terms:
Because CSS is calculated from core swimming, it gives you a clean, swim-specific reference point for intensity.
When swimmers wear a Polar Verity Sense, you’re no longer choosing between pace or physiology; you get both.
During practice:
After practice, this is where things become more precise. CSS on its own reflects core swimming only. That means kick sets, drill work, and equipment use (paddles, fins, etc.) aren’t fully represented by pace alone.
When CSS is combined with heart rate, TritonWear can:
In other words, CSS tells you what speed means. Heart rate tells you what it costs the swimmer. Together, they give you a clearer picture of effort, stress, and adaptation.
This doesn’t mean you need a heart rate monitor for every swimmer. It means:
Zones aren’t about what you planned. They’re about what actually happened across the entire practice. That’s where good coaching decisions come from.
All of that matters, but here’s the key shift: Training zones aren’t something you manage on a screen; they show up in how you write sets, choose rest, and decide when to push or hold back.
On deck, zones are controlled by how you manipulate:
You don’t need to label every set with a zone number. You need to know:
The zone definitions below aren’t meant to turn practice into a checklist. They’re a coaching reference, a way to sanity-check whether the work you’re planning actually matches the intent.
As you read through them, think less about memorizing details and more about this question:
“If I looked at this set after practice, would the training zones tell the same story I intended?”
Use this section as a reference, not a checklist.
Low-to-moderate intensity work is used for recovery, warm-up, cool-down, technique, and low aerobic work. There’s no performance pressure here.
Typical use:
Warm-up and cool-down
Recovery between harder efforts
Technique-focused swimming
Work:rest:
Easy pace with generous rest as needed to keep breathing relaxed and technique clean
What you’re looking for:
Relaxed breathing
Stable effort
No urgency
Sample set:
6 × 150 easy swim with fins @ 3:00
Optional focus: stroke count, long lines, clean turns, controlled breathing
The foundation of swim training. This zone builds aerobic capacity and efficiency through repeatable, sustainable work.
Typical use:
Base training
Aerobic maintenance
Technique under low fatigue
Work:rest:
Longer repeats with short-to-moderate rest to keep effort steady and sustainable
What you’re looking for:
Sustainable pace
Technique holding for long periods
Steady, controlled effort
Sample set (Pull/Swim Focus 4200):
6 rounds of:
400 freestyle pull, descending pace each round
Target example: @ 5:10 / 5:05 / 5:00 / 4:55 / 4:50 / 4:45
Optional skills to layer in:
UWS
Breath count
Stroke count targets
Other technical skills as needed
Optional equipment rotation:
2 rounds swim
2 rounds finger paddles
2 rounds fins
Zone 3 sits at or just below CSS. This is where swimmers learn to sustain meaningful speed and hold technique under pressure.
Typical use:
Aerobic power development
Race-specific endurance
Learning to manage discomfort
Work:rest:
Moderate rest that allows repeatable quality without turning it into sprint work
What you’re looking for:
Hard but controlled effort
Technique holding under pressure
Heart rate rising and stabilizing
Sample set (Zone 3 / A3):
15 × 150 freestyle
Descend 1–3 (3rd is on goal pace for the set)
Then:
9 × 100 free A3 (max heart rate-30) @ 2:10–2:20
Then:
16 × 100 free HR A3 (max heart rate-30) @ 1:30–1:40
Adjustments based on group and event focus:
Pace times can be adjusted based on swimmer's level and the season phase
Sprinters can reduce total volume
Middle distance and distance groups can hold full volume
Stroke integration options (if technique stays strong):
Flyers or breaststrokers: 3 free, 3 stroke
200-stroke swimmers can rotate 150s as:
100 free / 50 stroke
50 free / 100 stroke
150 stroke
100-stroke swimmers can rotate as:
1 free
1 as 50 stroke / 100 free
1 as 100 stroke / 50 free
In TritonWear, Zone 4 targets VO₂ max. This is high-intensity aerobic work where swimmers push oxygen uptake and fatigue builds quickly.
Typical use:
Aerobic power development
Preparing swimmers for race-level intensity
Work:rest:
Intervals are challenging and require intentional recovery to maintain best average speed
What you’re looking for:
Very high effort with repeatable speed
Rapid breathing
Technique under stress without collapsing
Sample set (Zone 4 / Best Avg 3K):
3 rounds of:
2 × 100 free @ 1:20
Goal:
Hold the fastest possible pace for all distances and all rounds
Optional equipment rotation:
1 round swim
1 round finger paddles
1 round big paddles
Max intensity work focused on speed and power. Rest is non-negotiable to keep efforts truly sprint-based.
Typical use:
Sprint development
Race-specific speed
Neuromuscular sharpness
Work:rest:
Long rest intervals to protect speed and technique quality as fatigue rises
What you’re looking for:
Max speed and commitment
Clean mechanics under pressure
Fast times that stay repeatable
Sample set (Zone 5 / Race Pace 50s + Stroke Pace):
Round 1
16 × 50 as 3 free + 1 stroke
@ 0:50 rest
150 easy swim with fins @ 3:00
Round 2
12 × 50 as 2 free + 1 stroke
@ 1:00 rest
150 easy swim with fins @ 3:00
Round 3
8 × 50 as 2 free + 1 stroke
@ 1:10 rest
150 easy swim with fins @ 3:00
Round 4
4 × 50 stroke
200 race pace or faster (goal time)
@ 1:20 rest
Instead of asking: Did we hit the zone? Ask:
Training zones aren’t about control. They’re about clarity. When you use them well, they make you a calmer, more confident coach, and that shows up in your swimmers’ performance.
Good coaching isn’t about assigning zone numbers. It’s about understanding what stimuli you’re creating in the water and how your swimmers are responding. By tying swim sets to zone logic, we create a common language everyone on deck can see, hear, and feel.