Most competitive swimmers don’t just jump the water and swim straight for an couple of hours before hitting the showers, unless they’re an ultra-distance swimmer…or a loner.

Instead, a coach gives a series of “sets” designed to work various aspects of the swimmer’s stroke and fitness. For example, one or two sets might be given as a warm up; then perhaps a set to focus on the swimmer’s kick; then another that focuses on swimming at race pace; and so on. A single set might take the form of, say, 8 x 100s (25 drill, 75 swim).

Occasionally, a coach will set a rest period between each repetition, like 15 seconds rest between each 100. But, more often than not, a coach will give a specific interval for each rep. So, for example, the 8 x 100s above might be “on the 2:00.” That means the swimmer has two minutes to complete each 100 swim. If the swimmer completes the 100 in 1:30, they have 30 seconds rest before starting the next one. If the swimmer goes faster, they get more rest. If they go slower, they get less. This is called interval training and it’s a great idea for you, if you are training for a triathlon.

Here are some reasons you should try to incorporate interval training into your workouts.

It’s a Monotony Breaker
Breaking a straight 800 swim into 8 x 100 can make workouts much more fun. Even having 10 seconds to lift your head and look around can help break the monotony of a straight 800 swim. Swimmers also get to interact with a coach and other swimmers — to receive feedback, encourage each other and confirm the number of reps to go.

In addition, many coaches take the opportunity to place some variety within each rep. So, for example, in the 8 x 100s example above, the first length is drill. This again breaks up the monotony of a straight 100 swim.

Intervals Provide a Challenge
Intervals add a whole new dynamic to the workout. You or your coach can change the intervals to experiment with different speeds. If you have 15-30 seconds rest between each 100, you can probably hold a faster pace that you would normally hold by swimming straight through.

On long sets, it’s common for swimmers to get the most rest on the first rep, less on the second before settling into a groove. Interval training, therefore, helps the swimmer establish a feel for their pace. This becomes extra important on race day, when it’s common for excitement and adrenaline to cause a triathlete to swim harder than they need to.

Get Real-Time Feedback
After a while, you’ll realize that intervals that used to give you 20 seconds rest are now giving you 30 seconds comfortably…you’re getting fitter and faster! So, interval training gives you better real-time feedback on how you are doing than swimming straight through.

Interval training is a wonderful thing for triathletes. If you aren’t already doing some of it, you should try it.

However, it’s important that you find the right intervals for you. If you have someone that’s a similar ability to you, then you can use the same intervals. But if you’re swimming, say, 100s with a group and someone is getting 45 secs rest, another 20 secs and another 5…that’s not good. Each group is probably working a different system.

In the next post, I will suggest a way for you to determine your intervals.