IRONMAN Switzerland Thun

Arrive early, get a quick warm-up in the water, and use the first few minutes to settle your breathing rhythm before you push. With a 3,866 m swim, prioritize calm, efficient strokes and positioning over forcing speed—aim to start “controlled,” then gradually build to race pace. If the start is crowded, stay patient for the first stretch so you don’t get tangled chasing clear water. Spend a moment at the end of the swim focusing on your exit plan: stand up cleanly, head straight to the racks, and transition efficiently into your bike gear.

You’re racing 3,866 m in freshwater where the temperature varies, so expect your body to feel different in the first few minutes than it will later—go slightly conservative at the start and let the pace come to you. Focus on steady effort and smooth sighting; avoid big surges because the swim sets up how smoothly your bike can start. With moderate conditions and wind that can influence surface chop near shore, keep your stroke rate consistent and aim for straighter lines to minimize distance lost. Fueling during the swim should be minimal and primarily about readiness—your main carbs and sodium plan is best executed after you’re on the bike and running.

Think of T1 as a gear-to-gear flow: exit fast, stabilize your shoes/socks workflow, and commit to a smooth mount. On the bike, your first 10–15 minutes set the tone—focus on calm cadence, stable power/effort, and getting your hydration moving so you don’t wait until you feel thirsty. Because this course is 178.8 km with 1,711 m of elevation and a hilly/climbing profile, plan to keep intensity “under control” early so the climbs don’t turn into repeated red-lines. Start with an easy-downshift mindset: you’ll be better off arriving at the first major climb with legs ready.

This bike is 178.8 km with 1,711 m of elevation, so expect repeated climbing demands and choose a pacing strategy that stays repeatable across hills. Use the light N wind (2.2 m/s) as a pacing cue: when you’re working into it, your effort will rise faster than you think—hold your planned output and don’t let speed drive your intensity. On climbs, prioritize cadence that you can sustain; on descents, stay efficient and composed, then re-stabilize immediately for the next effort. Stick to your fueling targets consistently: aim for 90 g carbs per hour, 750 mg sodium per hour, and about 650 ml fluid per hour, adjusting slightly if you’re sweating more or less in the 14.6–23.1°C air range. Take in fuel/drink at a steady cadence so you’re not “catching up” later when the hills already cost you.

T2 should be about leg management. As you rack down and start the run, expect your quads/hips to feel “switched on” immediately—keep the first 1–2 km controlled so you don’t overstride while you’re adapting to the bike-to-run transition. Since the run profile is listed as unknown, use feel and breathing to guide effort early: settle into a sustainable pace before trying to pick up speed. Transition quickly and then focus on quick, efficient steps rather than chasing early pace.

The run is 42.2 km and the elevation gain isn’t specified, so treat this as a long-duration pacing challenge first and a terrain challenge second. Keep your effort steady and avoid the common mistake of ramping too hard early—if the course has any rolling sections, those tend to steal rhythm and increase perceived effort. Moderate heat (air temps roughly 14.6–23.1°C) means hydration and electrolytes matter even if it doesn’t feel hot at first; take fluids and carbs regularly to prevent late-race fade. Continue your race fueling targets during the run: 90 g carbs per hour, 750 mg sodium per hour, and about 650 ml fluid per hour, using aid stations as your timing anchors. If the north wind shows up more on exposed sections, use it to stay composed—don’t let it tempt you into surging; keep your stride controlled.