Review of Interval Training Sets for Swim Speed

Just like on the track, intervals in the pool sharpen speed, raise threshold, and improve pacing. The water adds unique variables—turns, streamline, walls—that can make or break outcomes. Here’s how to use intervals deliberately.

Why Intervals Work

Dose intensity without frying: Hard efforts with structured rest keep technique intact.

Specificity: Short repeats rehearse breakouts, underwater kicks, and finishes under fatigue.

Feedback loops: Times per repeat show real progress.

Core Formats

VO₂/Speed: 25s/50s fast on generous rest (e.g., 12×50 @ :60 fast/strong). Emphasize explosive push, 5–8 underwater kicks, and clean breakout.

Threshold (T-pace): 100s/200s on moderate rest (e.g., 8×100 @ send-off that gives 10–15s rest). Aim even or slight descend.

Broken swims: Split a race distance with short rests (e.g., 3×(100 + :10 rest + 50 + :10 rest + 50)). Trains race skills without full fatigue.

Lactate tolerance: Fewer reps, long rest (e.g., 6×50 all-out on 2:00). Great for sprinters; use sparingly.

Technique Priorities Under Fatigue

Streamline first: Tight line, locked arms, head neutral.

Underwaters count: Commit to a fixed number each wall—don’t let it degrade.

Stroke count & rate: Track strokes per length; avoid thrashing as fatigue rises.

Turns: Last stroke into wall should be long and patient, not a rushed slap.

Sample Weeks

Sprint bias: Tue speed 25s/50s; Thu power kicks; Sat broken 100s.

Middle distance: Tue threshold 100s/200s; Thu pace 50s from a dive; Sun negative split 400s.

Tri/Open water: Longer threshold/pull sets, sighting inserts every 6–8 strokes.

Pacing & Send-Offs

Pick a send-off that leaves 5–20s rest depending on focus. If rest drops below target, extend the interval or reduce reps to protect form.

Verdict

Intervals are the backbone of faster swimming—if you honor walls, underwater phases, and pacing discipline. Choose the right format for your event, protect technique as speed rises, and let the clock keep you honest.

-Thomas