Training by time versus distance

What’s the difference between swimming 100 metre repeats in two minutes and swimming two minute repeats covering 100 metres?

Nothing right? Well actually, it might just depend on who you ask.

For most of us, one option (training either by distance or time) will seem inherently easier than the other. Some triathletes prefer to train by distance, swimming 100m repeats, running 1K intervals, an 80 km long ride. Others train by time, completing 45 minutes in the pool, five-minute running intervals, or a long ride of three hours. Physiologically, both types of training produce almost identical adaptations as they stress the same energy systems in the exact same way and lead to the same adaptations and improvements. Both will make you fitter and faster.

Psychologically however, one type likely seems harder than the other.  And there may be a reason for that.

If you think about it, how far is 30 minutes of riding? You may have some idea but this can only be imagined. You can’t really see the finish until you reach it. As a result, you may find yourself constantly checking your bike computer to see if/when time is up. On the other hand, you kind of know exactly how far 40 km is and depending on where you start, you know exactly when it will finish. That is to say, 40 km or any pre-determined distance is an observable phenomenon and therefore requires less mental muscle to figure out when it’s over.

For this reason, many triathletes feel that training by distance is easier and therefore, preferred. And why not? Pretty much every race is a set by distance, not time. It may also not surprise you to discover that you can probably cover a set distance (say a 5K run) in less time than if you simply ran that same amount of time (say 23 minutes) and tried to cover that set distance. Simply put: training by distance feels easier. But covering a distance in the fastest amount of time is not always the purpose of the run, which is why easy, recovery and some long workouts should be done by time instead.

You should however aim to include a variety of both types of training into your routine and should experiment to see which type works best for you. Swimming, riding and running by distance may seem easier but going by time is probably better for building mental toughness and therefore has an important place in training.