How do you know if you're ready to swim a mile?

A mile has a lovely ring to it. It sounds serious without being heroic, and in a 25-metre pool it works out at roughly 64 lengths, which is a lot of looking at a black line. The good news is that being ready for it has very little to do with speed and a great deal to do with comfort.

The signs you are nearly there

• Half feels ordinary. If you can swim around half a mile, continuously and without feeling ragged, the full distance is a question of time rather than talent.
• Your breathing has a pattern. You are not snatching air; you breathe on a rhythm you could keep up while thinking about lunch. If this is still the sticking point, our guide to breathing in front crawl is the place to start.
• You can rest without stopping. Slowing right down, rolling onto your back for a few strokes, or switching to an easy breaststroke are all ways to get your breath back while still going forward.
• You finish with something left. At the end of your longest swim, you could do one more length if someone asked nicely.

If you recognise three of the four, you are close.

Building up without making it a chore

There is no need for a programme. A few simple habits get most people there:

• Swim in pieces. Break the mile into sets you can manage, such as four quarters or eight shorter swims with a short pause at the wall. Over the weeks, shorten the pauses and lengthen the pieces until they join up.
• Add a little at a time. One extra length or two on your longest swim each week is plenty. The mile will still be there next month.
• Swim slower than you think. Most people who struggle with distance are swimming their first lengths too fast. Pick a pace that feels almost lazy and hold it.
• Count in chunks. Counting 64 lengths one by one is how people lose count at 37. Count in blocks of four or eight, or use the clock instead.
• Change the scenery in your head. Some swimmers practise a stroke detail for a few lengths, then switch to another. Our piece on lap swimming without boredom has more ideas.

Pool mile or open-water mile

They are different animals. A pool gives you walls, clear water, a rope and a lifeguard. Open water gives you scenery, cooler temperatures, chop, no walls to rest on and the small matter of swimming straight without a line underneath you. If your goal is an outdoor mile, do your first one in the pool, then build up outdoors gradually, at supervised venues, with company, and following local safety advice. Our guide to getting into open-water swimming covers how to start.

Swim events: the fun part

Many lakes, lidos and seaside towns hold organised swims over a mile or thereabouts, often with a festive atmosphere, a finish line on a beach and a cup of something warm afterwards. They are a lovely target because:

• the course is marked and supervised,
• you swim with hundreds of people of every age and speed,
• and the finish photo is much better than one of a pool clock.

Read the event's own guidance carefully, including any cut-off times, wetsuit rules, water temperatures and minimum ages, and choose one that suits your experience. If you have never swum in open water, look for an event that offers acclimatisation swims or a shorter distance first.

What the day itself feels like

The first few hundred metres often feel worse than the rest, because everyone starts too fast and the body takes a while to settle. Expect that, and keep the pace easy. Somewhere around the middle the rhythm usually arrives, and the last part tends to feel better than you feared. When you finish, sit on the edge, enjoy the slightly wobbly walk to the changing room, and let yourself be a bit pleased.