Your indoor bike training setup

Most triathletes do a big share of their bike training indoors: it's time-efficient, safe in the dark and the weather, and easy to make structured. Here's how to put together a setup that you'll actually want to ride.

1. Choose your trainer

There are three main types:

• Wheel-on: your bike's back wheel presses against a roller. Usually the cheapest, and quick to set up, but it wears your rear tyre and tends to be louder.
• Direct drive: you take the back wheel off and mount the bike on the trainer's cassette. Quieter, steadier, and usually more accurate on power.
• Smart bike: a complete indoor bike. No swapping your own bike on and off, but it costs the most and takes up a permanent spot.

A "smart" trainer connects to apps and can set its own resistance. The feature to look for if you follow a plan is ERG mode, which holds the exact wattage a workout asks for. The smart trainer picker scores trainers on the specs their makers publish: maximum simulated climb, power accuracy, ERG, folding and whether a cassette is included.

2. Check it fits your bike

Before you buy, check the trainer's compatibility list against your bike:

• Axle type: quick release or thru-axle, and the axle size.
• Gearing: a direct-drive trainer needs a cassette that matches your bike's number of gears. Some trainers ship with one; others don't.

If you're unsure, a bike shop can tell you in a minute. Riding a road bike on the trainer and wondering about aero bars? The tri bike decider has a straight answer.

3. Keep cool

Indoors there's no wind to cool you, so heat builds up quickly. A strong fan pointed at you makes the biggest difference to how hard you can ride and how long you'll want to stay on. Keep a towel within reach, and drink to your plan just as you would outside. The nutrition calculator can help you think about fluid and sodium for long sessions.

4. Protect your floor and your bike

A trainer mat catches sweat and reduces noise for anyone below you. Sweat is hard on bikes, so wipe the frame, bars and headset area down after each session.

5. Pick an app and a way to see your numbers

Training apps range from structured workout libraries to virtual worlds you ride through with other people. Most smart trainers work with the popular ones, but check the app's own compatibility list. A heart-rate strap or a watch that shows your data live is useful too. The watch comparison shows battery life and triathlon modes side by side.

6. Train by zones

Indoor sessions are where structured training shines. Do an FTP test, then use the training zones calculator to turn it into power zones, plus heart-rate zones for the bike and run. Retest every six to eight weeks. To see how your bike speed would play out on race day, try the finish time predictor.

7. Make it easy to start

The best setup is the one you'll use. If you can, leave the bike on the trainer with the fan, towel and bottle ready to go, so getting started takes a minute, not twenty.

Comparing two trainers? Head-to-head comparisons put their specs side by side.