Swim Sessions for Adults Who Start or Return

The competitive swimming document in this knowledge base describes squads that swim 20,000 metres a week or more. Most adults who choose swimming for fitness start far below that: a few hundred metres per session, front crawl that breaks down after one or two lengths, and shoulders that are not used to the load. This document describes how their pool sessions are built, so that a plan for them is varied, measured in metres and safe for the shoulders.

What the evidence says about untrained adults

Swim training works for people who are not swimmers. Across controlled trials in non-elite swimmers, swim training raised maximal oxygen uptake by about 6 mL/kg/min in healthy adults and reduced body mass and body fat.

Previously sedentary adults can start with short sessions and build up. In a twelve-week trial with sedentary adults over 50, sessions began at 15–20 minutes, three to four days a week, below 60% of maximal heart rate, and grew to 40–45 minutes at 70–75% of maximal heart rate as fitness and skill improved. Systolic blood pressure fell from 131 to 122 mmHg.

Both continuous and interval swimming work. In a fifteen-week trial with sedentary women aged 35 to 49, three sessions a week of either one hour of continuous front crawl or 6–10 all-out 30-second efforts with two minutes of rest lowered blood pressure and resting heart rate, and improved swim performance.

How fast beginners swim

The same trial measured how far the women could swim in ten minutes at maximal effort. Before training they covered about 305 m, a pace of about 3:15 per 100 m. After fifteen weeks the continuous group covered about 370 m, about 2:45 per 100 m.

Easy swimming is slower than a ten-minute maximal effort. For planning, a session is sized with these easy paces:

Level	Easy pace per 100 m	Where it comes from
Sedentary	3:45	About 87% of the speed of a sedentary adult's ten-minute maximal swim (3:15)
Novice	3:10	About 87% of the speed after fifteen weeks of training (2:45)
Recreational and above	2:30	The pace the app already assumes for swimming; a working assumption, not a measurement

The athlete's own recorded swims replace these numbers whenever they exist. A pace that is too fast for the athlete makes every session longer than planned, so the table errs on the slow side.

How a session is built

Every session has four parts:

1. Warm-up: about 15% of the session, easy swimming in any stroke, at least 100 m.
2. Technique: drills and kick. About 20% of the session, and about 35% on the session of the week dedicated to technique. Technique comes first in every session, because in water a better stroke saves more energy than extra fitness.
3. Main set: the largest part of the session, swum as repeats with rest at the wall.
4. Cool-down: about 10% of the session, easy swimming, at least 100 m.

Distances are in metres, in multiples of 50 m, so that every repeat ends at the wall of a 25 m or 50 m pool.

Drills isolate one part of the stroke: catch-up, fingertip drag, side kick, single-arm freestyle, fist swimming, six-kick switch. Kick sets use only the legs, usually with a kickboard. Rotating the drills from session to session keeps the technique work varied.

Repeats and rest

Beginners swim short repeats and rest at the wall between them. Rest takes at least 30 seconds.

Level	Main-set repeats	Rest	Through the phase
Sedentary	50 m	45 s	Repeats grow to 100 m, rest shrinks to 30 s
Novice	100 m	30 s	Repeats grow to 200 m
Recreational	100–200 m	30 s	One threshold set a week, as repeats of 200 m
Trained	200–400 m	30–45 s	Threshold repeats of 400 m
Competitive	Up to 400 m	30–45 s	Adds 100 m repeats at VO2 max pace, with rest about as long as the repeat

The threshold and VO2 max sets follow the training zones of the competitive swimming document: threshold work is swum as repeats of 200–400 m with 30–45 s of rest, and VO2 max work as repeats of 100 m with a work-to-rest ratio of about 1:1.

Making the week varied

Three sessions in the same week should not be the same session. With three easy sessions a week, one has the technique emphasis, one is built on aerobic repeats, and one has longer steady repeats. The repeats and the drills change from week to week. The lighter weeks keep the structure and shorten the main set.

A faster element, when the level allows it, is a short set of 50 m "builds": each repeat starts easy and finishes fast, with full rest. It is the swimming version of a runner's strides.

Shoulders

Freestyle is driven mostly by the upper body. Drills and kick sets spread the load, and the volume grows with the athlete's level rather than by a fixed percentage. Pain at the front of the shoulder is a reason to shorten the main set and see a professional, not to push through.