Why (and How) to Find Your Optimal 100-Yard Swim Pace

Whether your goal is to increase endurance in the water, boost top-end speed or refine technique, the basis of every swim workout should be interval training. That’s because the built-in rest and recovery helps you go longer while maintaining your form. If you’re a regular at your local Masters group, this is nothing new. If you’re the solo type who prefers to hop in the pool and swim at a consistent pace until boredom (or hunger) sets in, it might be time to re-familiarize yourself with the pace clock. It all starts with establishing your ideal 100-yard (or meter) base pace.

One of the most common sets coaches use to establish a swimmer’s base is to have them swim 10 x 100 at the fastest pace they can hold “comfortably.” This doesn’t mean their absolute threshold pace for 10 100s. “Comfortably” means getting about 5 to 7 seconds of rest between each 100. So, if Swimmer X can do 10 x 100 on the 1:30 and is consistently coming in on the 1:23, then 1:30 is the ideal base for that athlete.

This base can then be multiplied to establish the ideal pace for longer intervals, like 200s, 400s or 800s, but it’s important to keep in mind that you’ll be accumulating more rest during longer intervals. If Swimmer X were to perform 4 x 400 at a 1:30 base, that would mean each 400 would be swum at a 6-minute interval. If Swimmer X held his 1:23 pace, that means he would be getting 28 seconds of rest between each 400, which is obviously way too much. So for longer sets, a formula of (BASE –5 seconds) would be ideal. This means Swimmer X would be using a 1:25 per 100 pace for each 400 and should be getting about 8 seconds of rest between each interval. Five seconds of rest should be enough for 100 intervals and up to 10 seconds of rest is fine for 200s. For longer intervals, like 400s or 800s, no more than 15 seconds of rest should ever be needed.

Your base pace is valuable for providing a framework to build sets around, but a significant amount of time should be spent swimming faster than base pace, especially for athletes who are only able to get in the pool two or three times per week. “I’ve observed way too many athletes who just like to train at their base interval,” says veteran swimming coach Gerry Rodrigues of Tower26 in LA. “This presents the problem of working only one system. Most triathletes I observe train too slow in swimming by doing too many base intervals, or doing longer swims of 1K or more at slower intervals. It’s simple: train slow, race slow.”

There are also times to forget about base pace completely, and instead focus on pure intensity and swimming at or above race pace. The acronym commonly used by swim coaches is USRPT (ultra short race-pace training). These are shorter intervals—usually 25s or 50s—that are swum at a near all-out effort to simulate race-day speeds. For a USRPT set, Swimmer X might perform 12 x 25 on the 30-second interval. This is significantly slower than Swimmer X’s base pace, but the focus is on swimming each 25 as quickly as possible then getting plenty of rest. These kinds of sets are especially important as an athlete gets closer to race day and are best done near the end of a workout so your body gets used to performing well even when it’s tired.