Basic Intervals: Four Good Ways to Watch the Clock

1. FIXED-REST SETS

Example: 4 × 200 yards on 60 seconds rest

Number of repetitions: 4

Distance of each rep: 200 yards

Start each repetition: 60 seconds after finishing the last one

You don’t get intervals more basic than this, so it’s the place to start if you’re new. You’re guaranteed the same amount of rest, no matter how slowly or how fast you swim. For instance, do the first 200 in 3:00 and you start the second at the 4:00 mark. If your second 200 slows to 3:20, you start the third at 4:20, holding your minute’s rest no matter what.

To make it easier to keep track, most swimmers round off the rest to leave on a red mark on the clock. After a 200 at 3:17, they’d probably go again at 4:15 or 4:20, not 4:17.

2. FIXED-INTERVAL SETS

Example: 8 × 100 yards on 2:00

Number of repetitions: 8

Distance of each rep: 100 yards

Start each repetition on: 2:00 (includes swim time plus rest time)

This is fairly basic too, but it’s a little tougher and more strategic than #1. You start each 100-yard repeat two minutes after starting the previous one, regardless of how much or little rest that gives you. Finish the first 100 in 1:30 and you get :30 off. Slip to a 1:35 pace on the second and your rest before you start your third repeat slips too: to :25. The only way to keep the slope from getting steeper and steeper—and each repeat from probably getting harder and harder—is to keep up, which means swimming close to the same pace on all eight. Since your tank gets lower each time, you have to figure how to parcel out the work (we explain this in our next chapter on racing) a little better each time so you end up swimming numbers one and eight at the same speed.

3. DECREASING-INTERVAL SETS

Example: 5 × 50 yards on intervals of 1:00–:55–:50–:45

Number of repetitions: 5

Distance of each rep: 50 yards

Start each repetition on: decreasing rest

Decreasing-interval sets are tougher yet than #2 because on each successive repeat, as you’re growing more tired, you automatically get less rest.

Take the example above. The first interval (preceding the second repeat) is 1:00, the next is :55, and the last is :45. So if you swam each repeat in :40, you’d rest :20 before swimming the second, :15 before starting the third, :10 before the fourth, and just :05 before the fifth.

Not for sissies. But believe it or not, an accomplished repeat swimmer can actually swim slightly faster on each succeeding repeat, regaining a sliver of lost rest.

Decreasing intervals are often used by coaches to get you used to the tough challenge of holding your pace in a race, when everything in your body is beginning to say, “Hey, take it easy, will you?”

4. INCREASING-INTERVAL SETS

Example: 8 × 50 (1–4 on 1:00, 5–8 on 1:30)

Number of repetitions: 8

Distance of each rep: 50 yards

Start each repetition on: 1:00 for first half, 1:30 for second

This seems like it gives you a break, since you get :30 more rest before each repetition in the second half than in the first. But there’s a catch: With that extra rest, you’re supposed to swim faster. (And if you do, as we now know, you get still more rest if you’re swimming fixed intervals like these.)

The increasing interval is usually used by coaches to speed you up as the set progresses, since the added rest makes the intervals easier to swim harder and faster. It’s a kind of rehearsal for finishing a set (and hopefully a race) strongly.

Interval design is limited only by a coach’s creativity, and over the years many of us have gotten pretty creative. In fact, you could probably write a whole book just on the elaborate schemes that have been devised to organize your pool time with your eye on the pace clock. “Descending sets” are sets that grow faster one by one, “ladders” and “pyramids” either increase the length of each rep or increase it for half the set and then shorten it again on the other half. If that’s not enough to keep track of, rest changes too, since it’s usually calculated from the length of the leg you’ve just done. And in mixed-distance sets everything is in play, with distances and rest intervals changing and changing again.

But the four bread-and-butter interval formats above will give you the most direct route to improvement, and they don’t take a waterproof calculator to keep track of. Besides, it’s what you put into each length—not how elaborately your whole program is organized—that gets results.

The “starter kit” opposite uses nothing fancier than fixed-rest sets. But it will groom you for any goal from basic fitness to a race time you’ll be proud of. Just make sure you follow the weekly yardage guidelines. The tougher work, for race-readiness and speed, is like a powerful medicine. You should take just the prescribed amount for best results. More is not better—and can be harmful.