Master the Pace Clock: 4 Workouts

On a recent trip to Southern California, I dropped in at a Master’s swim practice with Gerry Rodrigues, the owner and head coach of the well-known Tower 26 training group. Rodrigues assigned me to a lane with four other swimmers based on the swim times I gave him. I hopped in, assuming the fifth, or caboose position in the lane, just in case I wasn't able to keep up. I didn’t grow up swimming, so I’m always a little intimidated when swimming with new people.

We warmed up for a solid 1,000-plus yards and then started the main set. The first part was 4 x 300 yards on a 4:45 minute interval. We were to swim the first 25 yards butterfly and then settle into freestyle swimming at a strong aerobic pace for the remainder. As I came into the wall at the end of the first 300, I heard Rodrigues stop all the swimmers from taking off for the next interval. "Who can tell me what time they just swam?" he shouted. Only two swimmers of more than 40 could actually report the time they touched the wall. I definitely wasn’t one of them.

Rodrigues clearly had a major point to make. "You need to know what a strong aerobic effort feels like and what that translates to in time," he told the pool full of swimmers. He urged us to make the emotional connection between the time we see on the pace clock and the effort we were exerting. He continued: "It’s important to be highly present in swimming, and one of the ways to measure presence is through using the pace clock. What does an interval in a given time feel like?"

Rodrigues is often astounded that triathletes are quick to remember their 10k or half marathon times, but can’t tell you their best 1k or mile time in the pool. "There’s this disconnect from swimming performance relative to riding and running performance," he says. He thus urges athletes to use the pace clock and make an emotional connection with their times: "It will help triathletes gain a good sense of how they should be able to perform in a race situation."

If you’re new to swimming, the pace clock and the accompanying terminology might seem confusing. As we've seen from one of the sport's leading swim coaches, however, it's actually a tremendous tool to gauge effort levels, pacing and progression in swim training.

Emma-Kate Lidbury is a professional triathlete who has trained with Rodrigues in the past. She uses the pace clock in all of her swim sessions, even the easy ones: "The pace clock is the only form of external feedback available to us as we swim so it is a vital part of the training process," she says. "I'll ensure I can see the clock as I flip turn so that I can monitor my splits and adjust my effort accordingly." Lidbury even uses the clock to help her focus on technique: "If I'm swimming slower than expected for a given effort, it forces me to think about stroke mechanics and efficiency and make changes."

Meet the clock: 4 sample sets

A typical pace clock is usually a plain clock face with a minute hand and a second hand with numbers dividing the minute into 5-second increments. The 60 second mark on the pace clock is frequently referred to as "the top" and the 30 second mark is "the bottom." Some pools use a digital clock, but you can easily learn either method. Below are three sample sets to get you acquainted with using a pace clock.

1. The simplest interval is a one-minute interval. You swim a specified distance a certain number of times, e.g. 10 x 50 yards, starting each interval exactly one minute after you started the prior interval. This means if you swim 50 yards in 45 seconds, you have 15 seconds to rest before starting the next 50 yard interval.

Try it: Swim 10 x 50 on the one minute interval. If you get back to the wall at 50 seconds, you get 10 seconds rest. If you get back to the wall at 55 seconds, you only get 5 seconds rest. 

2. What if the interval isn’t a minute? Doesn’t that make things trickier? Indeed, at first glance leaving on intervals other than a minute appear more complex, but you can take advantage of patterns and simple math to assist you.

Try it: Change your interval on the above 10 x 50 yard workout to 50 seconds. Now you will start the first interval on the top (60), the second on 50, the third on 40, the fourth on the 30 and so on. The pattern is simple: on each repeat, you start 10 seconds earlier on the pace clock than the prior one. If, like me, you sometimes lose count when doing intervals, the clock pattern of decreasing the number by 10 seconds each time can help you keep track. When your starting interval returns to the top (60) you will have completed 6 intervals … just four more to go!

3. The same counting methodology and pattern also applies if you’re doing different distances, such as 100's or 200's. 

Try it: Now try 10 x 100 yards on a 1:45 interval. It doesn’t matter that the clock does an entire revolution before you’re done. If you leave on the top, all you need to focus on for your second 100 yard interval is the 45 mark on the pace clock, then the 30 for your third, 15 for your fourth, and so on. And in this case, starting from the top for a second time means you have completed four intervals.

4. If you want to truly test your mastery of the pace clock, and see how it can improve your swimming, try this "limbo" workout from Rodrigues. The pattern of decreasing intervals echoes the lowering of the bar in the game limbo, hence the name.

Try it: 10 x 200 yards on an interval that decreases by 5 seconds on each repeat.

As an example, Lidbury will start this set by completing a 200. She'll leave for the next one at 3:00. For the next 200, she'll leave on the 2:55, then for the next, 2:50, then 2:45 and so on all the way down to 2:15. In pace clock terms, she’ll be leaving on the top (60), then the 55, the 45, the 30, and so on, leaving from the top again on the ninth interval and on the 15 for the tenth and final 200 yard interval.

Lidbury says she likes this workout because in addition to smart use of the pace clock, you get a step up in effort and intensity to make the intervals by the end. "If you make it, you get to shout "limbo!" upon completion!" she adds.

If you're intimidated by the pace clock, grab a friend and head to the pool for some swimming and math. You'll become a better swimmer and triathlete in the process. 

Jordan Blanco is a multiple-time IRONMAN finisher and writer living in San Francisco.