Aerobic Base Sets
Purpose: build mitochondrial density, stroke efficiency, and the aerobic engine everything else sits on top of.
- 16 x 100 free @ 1:20, descend effort every 4 (1-4 easy, 5-8 moderate, 9-12 strong, 13-16 fast). Early season, senior group. Teaches pacing control without touching anaerobic systems.
- Ladder: 400 / 300 / 200 / 100 free, all at a steady aerobic effort with 20 seconds rest, 200 easy swim between reps if the group needs it. Good for building block volume in September or after a break.
- 6 x 300 @ 4:00, hold best average across all six. Mid-season aerobic maintenance for a group that's already added threshold and race-pace work — this keeps the base from eroding.
Threshold Sets (CSS / T-pace)
Purpose: raise the pace a swimmer can hold before lactate starts piling up faster than it clears.
Find CSS from a recent 400/200 time trial: CSS pace per 100 = (400 time − 200 time) ÷ 2. Example: 400 in 5:00, 200 in 2:20 → CSS = (300 − 140) ÷ 2 = 80 sec/100.
- 10 x 200 free @ CSS pace + 2 sec/100, 20 sec rest. Mid to late season, senior or advanced age group. This is the workhorse threshold set — enough volume to matter, enough rest to hold pace honestly.
- 5 x 400 @ CSS effort, 30 sec rest, descend 1-5. Early taper. Fewer, longer reps rehearse pacing discipline over race-relevant distances.
- 8 x 150 @ CSS − 1 sec/100, 15 sec rest, best average. Sharpening phase for 200/400 racers — short rest forces them to hold a pace slightly faster than true threshold in short bursts.
Race-Pace Sets
Purpose: rehearse goal pace under fatigue, train anaerobic capacity, sharpen turns and finishes.
- 8 x 50 @ goal 100 pace, 1:00 rest, best average within 0.5 sec. Taper, sprint group. Rest is generous so the pace stays honest — this isn't a conditioning set.
- 4 rounds of (4 x 50 @ goal 100 pace, 10 sec rest), 200 easy between rounds. Mid-season for 100/200 racers. Repeated race-pace bursts with a real recovery between clusters — trains the ability to reset and go again.
- 6 x 100 @ goal 200 pace + 1 sec, 30 sec rest. Taper for 200 specialists. Rest matches roughly what they'll get between prelim swims, not a training interval.
Kick-Heavy Sets
Purpose: leg strength, aerobic kick capacity, body position, and a break from full-stroke fatigue.
- 20 x 50 kick @ 1:00, odd 50s easy, even 50s build to fast. Early season, works for every group from age-group to senior. Builds kick tolerance without wrecking anyone.
- 8 x 75 kick (25 easy / 25 build / 25 fast) @ 1:30. Mid-season. The internal build teaches swimmers to change kick tempo on command, which shows up on race turns.
- 6 x 100 kick @ race-pace effort with fins, 20 sec rest. Taper, sprinters and IMers. Fins let them hit real race-pace kick speed without the load of a full underwater set.
IM Sets
Purpose: stroke versatility, transition skill, and a natural mix of aerobic and anaerobic work in one set.
- 8 x 100 IM @ 1:30, odd 100s aerobic, even 100s fast. Early to mid-season, any group with IM in the program.
- 4 x 200 IM @ threshold effort, 30 sec rest. Mid-season IM specialists. Long enough to expose a weak stroke, controlled enough to stay aerobic.
- 16 x 25 by stroke (4 fly / 4 back / 4 breast / 4 free) @ :30, max effort. Taper, IM and sprint groups. Short and fast — a confidence-builder before a meet.
Mixing and Matching
A full practice is just building blocks stacked with a purpose. The rule that matters most: don't stack two high-intensity blocks back-to-back without something in between to bridge the recovery.
A simple taper-week practice built from the pieces above:
- Warm-up: 400 free, 200 kick easy, 200 pull
- Kick block: 8 x 50 kick @ 1:00, build each one
- Main set: 6 x 100 @ CSS pace, 20 sec rest
- Race-pace finish: 8 x 25 @ max effort, 30 sec rest
- Cool down: 200 easy
The kick set here isn't filler — it's active recovery that keeps heart rate up without adding anaerobic load, so the swimmer arrives at the race-pace work with legs under them but not cooked. The same logic applies for aerobic-to-threshold days: a moderate kick or pull set between the aerobic main set and a short threshold finisher keeps the practice building instead of just piling volume on top of volume.
When you're stuck on what to write next, don't start from zero. Pick one aerobic or threshold block for the bulk of the practice, one kick or IM block to change the stimulus, and one short race-pace piece to keep speed in the legs. That's a complete practice, and it's the same process whether you're writing for October or the week before championships.
Once you've picked your blocks, SwimIQ can turn the rough plan into a clean written set, do the pace math for each rep, and flag whether the overall practice leans aerobic, threshold, or race-pace so you can see the training-zone balance before you hand it to the group.