IRONMAN 70.3 San Juan

Plan a short, controlled warm-up that settles your breathing and gets your arms moving efficiently before you enter the start corral. Since the swim is 1,905 m in freshwater and temperature varies, start a touch conservative for the first few minutes and focus on finding rhythm rather than chasing position early. Use your seeding to avoid getting boxed in at the start—once you’re clear, lock into a repeatable sight-breathing pattern and keep your effort steady through the main portion of the swim.

You’ll cover 1,905 m of freshwater swimming where temperature varies, so your early pace should be driven by comfort and consistent breathing. The course will be paced by your ability to hold technique as you settle—aim for smooth, efficient strokes rather than hard surges. With typical race wind conditions (south wind, 4.4 m/s), expect the surface feel to change slightly as you progress, so keep your line true and sight regularly to avoid drifting. Fueling during the swim should be minimal—save most intake for the bike and run—then transition quickly and cleanly into your hydration and carb plan.

Think T1 as a controlled flow: leave the swim with enough time to get your bearings, then move efficiently through transition without rushing. Put on your kit, secure hydration/gear, and get your first pedal strokes turning over smoothly before you ask for power. Because the bike is flat/fast (90.2 km) with 255 m of gain, set your first 5–10 minutes to establish rhythm and breathing, not to jump into race intensity.

Ride 90.2 km on a flat/fast course with 255 m of elevation gain, so the biggest performance driver is staying smooth and consistent rather than reacting to every little stretch. With air temperatures ranging from 13.4–24.9°C and a south wind around 4.4 m/s, you may feel subtle headwind/tailwind shifts—stay composed, keep cadence steady, and avoid over-accelerating on tailwind sections. Execute your planned fueling from the start of the steady riding: target 90 g carbs per hour, 750 mg sodium per hour, and about 650 ml fluid per hour. Use that intake to prevent “heat creep” later—sip regularly (don’t save it for the end), and if you notice salty sweat or thirst rising, prioritize fluid and sodium consistency over chasing more speed.

In T2, expect your legs to feel heavy for the first few minutes—focus on getting your stride mechanics aligned quickly. Remount your cadence early and keep the first mile controlled while your breathing settles into run mode. Because the run is 21.6 km with only 42 m of gain (flat/fast), you can run aggressively later, but start by locking in rhythm rather than sprinting out of T2.

Run 21.6 km on flat/fast terrain with 42 m of elevation gain, so the temptation will be to go out too hard—resist and build into it. Moderate heat and air temperatures up to 24.9°C mean you’ll need to manage hydration rather than rely on speed alone. As you settle in, use your fueling plan from the first steady portion of the run (carbs 90 g/hr, sodium 750 mg/hr, fluid 650 ml/hr) to prevent energy dips and maintain output. With a south wind around 4.4 m/s, conditions can feel cooler or warmer at different points—keep judging by how you’re breathing and your thirst, not by watching the clock.