Many adult triathletes didn’t grow up swimming. You’ve got great endurance from the bike and run, but in the pool your easy pace and your flat-out pace are often too similar — so the threshold pace never really shifts.

Yes, technique matters. But you also need to swim fast sometimes — truly fast — over short intervals. That’s how you raise top-end speed so your threshold pace can climb with it.

The “One-Speed” Trap

Through winter, lots of adult swimmers “plod up and down” at a steady pace. It builds comfort and basic efficiency, but without touches of real speed, your body never learns to move water faster. If your max speed never changes, your threshold pace barely moves.

The Fix: Short, Hard Intervals

Add a small, regular dose of high-quality speed. Keep efforts short so you can hold form at real speed, and rest enough to repeat quality.

• 8–12 × 25 m fast (20–30 s rest)
• 6–8 × 50 m hard (40–60 s rest)
• “Broken” 100s (e.g., 4 × 25 m with 10 s rest between 25s)
• Fins or small paddles occasionally for feel, timing, and power

These sets lift your top end; once that rises, your threshold pace follows. Do this once per week consistently and you’ll feel the difference.

Technique Still Matters — Apply It at Speed

Use drills to refine body position, timing, and catch — then immediately apply those cues at higher speed. That’s how form sticks when it counts.

Example session flow:

• 10–15 min warm-up + drills (e.g., scull, kick on side, catch-up)
• 8 × 25 m fast, focus: the same cues you drilled
• 4 × 100 m steady aerobic, smooth and controlled
• 8 × 25 m fast again, hold form but work hard
• Easy 200 m cool down

Why Short Intervals Help Your Form

Fast but controlled swimming naturally improves mechanics: taller posture, better alignment, quicker turnover, cleaner catch. Long steady swims build aerobic fitness, but they don’t challenge coordination the same way. Short, hard efforts sharpen form and speed together.

Your Winter Swim Framework

Two to three swims per week is plenty if the quality is high. Try this rhythm:

• Session 1 — Technique + Speed: drills → 25s/50s fast with full control
• Session 2 — Aerobic: relaxed 100–300 m repeats, smooth pacing
• Session 3 — Strength/Threshold (optional): pull or paddles, controlled strong work

Keep speed volume modest (10–15 minutes of total fast work). Prioritise quality over quantity.

The Takeaway

Don’t spend the whole winter in one gear. Blend short, fast intervals with focused technique so your body learns to hold good form at higher speeds. Do that consistently and your threshold pace will rise — making race-day swimming smoother, faster, and far less stressful.

At Enduraprep, Coach Cronk builds swim programmes that balance form, fitness, and speed — so you improve where it matters most.