Dynamic Apnea Training: Pool Sessions That Actually Work

Dynamic apnea training is underwater swimming on a single breath in a pool, either with fins (DYN) or without them (DNF), while a trained buddy watches from the surface. The sessions that work best are mostly submaximal: technique lengths, repeated short swims with set rests, and the occasional longer, relaxed swim. Maximum attempts are rare. The pool is where you build an efficient kick and a quiet body, and those are what make long swims possible in the first place.

DYN, DYNB and DNF in plain terms

• DYN (dynamic with fins): any fins are allowed, and at the top level that means a monofin. Most beginners start with long bifins.
• DYNB (dynamic with bifins): recognised as its own discipline in some competitions, and the one most recreational divers actually train.
• DNF (dynamic no fins): a breaststroke-style arm pull and kick with long glides. Slower and more technical, and very good for learning to stay relaxed while working.

All of them are pool disciplines measured in distance. For how they sit alongside the depth disciplines, see our explainer on freediving disciplines.

Safety in Indian public pools

Blackouts in dynamic tend to happen near the end of a swim or in the seconds after surfacing, when oxygen is at its lowest. That is why the rules for pool apnea are not up for negotiation, and why understanding shallow water blackout comes before any distance goal.

Indian pools add a few practical problems:

• Pool rules. Some pools ban underwater swimming or breath-hold training outright. Ask the management before your first session rather than getting whistled out mid-length.
• Lifeguards. They watch the whole pool, and few are trained to recognise a freediving blackout, which is often silent and still. They are not your buddy.
• Crowds. Evening lanes are packed. An early-morning slot, a late slot or a booked lane makes safe training far easier.
• Equipment rules. Many pools insist on swim caps, and some restrict long fins in public lanes. Check before you turn up with a pair of fins nearly as long as your legs.

A short explanation to the lifeguard helps everyone. Something like: “We’re trained freedivers practising breath-hold swimming. One of us is always on the surface watching the other. If you see one of us lift the other’s face out of the water, please come and help.” Most lifeguards appreciate being told, and you have quietly added a second layer of safety.

What a good pool buddy does

• Follows on the surface, directly above or just behind the diver, for the whole swim.
• Watches the diver’s face and hands, not the far wall.
• Is ready at the finish to support the diver’s head if needed, and keeps watching for at least 30 seconds after they surface.
• Knows the rescue: bring the airway above water, remove the mask or goggles, then blow, tap and talk.
• Never does their own breath-hold at the same time. One up, one down.

There is more on this in our guide to the freediving buddy system.

Safety: Never do dynamic apnea, or any underwater breath-hold, without a trained buddy watching only you from the surface. A lifeguard watching the whole pool is not a buddy. Never hyperventilate before a swim, and end the session if you notice tingling, confusion or tunnel vision.

Warm-up: start every session the same way

1. 200 to 300 metres of easy swimming or finning on the surface.
2. A few minutes floating face-down with a snorkel, letting your shoulders drop and your heart rate settle.
3. Two or three short underwater swims of 15 to 25 metres with long rests, buddy watching. Keep these easy; they are part of the warm-up.

Four dynamic apnea session templates

Set distances from your current comfortable maximum, not from your best day ever. One person does the whole set while the other buddies, then swap roles.

Session	Main set	Rest between swims	Focus
Technique	6–8 × 25 m, or 15 m if you are new	2:00–2:30	One cue per swim: head, arms, kick or glide
Repeats	6 short swims, each well under half your comfortable max	Start at 2:30, drop 15 s per swim, never below 1:15	Staying calm as CO2 builds
Long and easy	2–3 swims at 60–70% of your max	3:00–4:00	A slow, smooth kick and a relaxed finish
No fins	6 × 25 m DNF, or 15 m if 25 m feels long	2:30	Long glides, counting strokes per length

The technique session is the one to do most often. Pick a single cue for each length, such as “chin tucked” or “kick from the hips”, and think about nothing else.

The repeats session is the wet cousin of a dry CO2 table. The distances stay short so that the challenge comes from the shrinking rest, not from going far. If a swim ever feels like a struggle, stop the set.

Long and easy swims teach you to pace yourself. The goal is to finish feeling as if you could have gone further, with a tidy surfacing.

Technique that pays off in the pool

• Head neutral. Look down at the pool floor with your chin slightly tucked, not ahead at the far wall. A lifted head acts like a brake. Our guide to streamlining and body position has drills for this.
• Kick from the hips. Long, unhurried strokes with fairly straight legs. Bending the knees too much is the most common fault. See freediving finning technique for more.
• Arms. Either stretched overhead with hands stacked and upper arms by your ears, or relaxed by your sides. Pick one and keep it consistent.
• Swimming depth. About a metre down, below the surface turbulence and clear of the floor.
• Weighting. In a swimsuit, most people need little or nothing. In a wetsuit, a light neck weight helps you stay level without fighting your buoyancy.
• Wall turns. A smooth turn with a gentle push-off saves more energy than a fast, flashy one.
• Surfacing. Come up slowly, hold the wall, and start your recovery breathing before doing anything else.

Measuring progress without chasing distance

Distance is the obvious number and the least useful one to chase. Better measures:

• Kicks or strokes per 25 metres at the same relaxed pace.
• How the last five metres of a set swim feel.
• How quickly you are ready to buddy after your own swim.
• Video. Ask your buddy to film one length from the side once a month, and compare clips.

When those numbers move in the right direction, your comfortable maximum tends to rise as well, without any max attempts.

Your next three pool sessions

• Session 1: Warm-up, then the technique set with one cue only: head position.
• Session 2: Warm-up, then the technique set focusing on the kick, plus two long-and-easy swims.
• Session 3: Warm-up, then repeats at a distance that feels almost too short.

Film a length during session 3 and watch it back with your buddy. The freediving.in community for Indian freedivers is coming soon, so stay tuned.