My First Ironman: The Road to Challenge Roth 2026
From marathon runner to Ironman. This is my documented journey preparing for my first full-distance triathlon at Challenge Roth 2026 - 3.8km swim, 180km bike, and a full marathon to finish. A journey that started with loss, but continues with love.
In loving memory of Rose Prommer (1945-2025). Your love is my endurance.
Building aerobic foundation through consistent zone 2 training. Focus on swim technique improvement and establishing training habits across all three disciplines. 99 days until Challenge Roth.
Coaching Team
Rob Wilby
Head Coach, Team Oxygen Addict
Ironman University Certified Coach and 220 Triathlon's Coach of the Year (2019). Former GB Age Group triathlete with six Ironman finishes. Hosts the popular Oxygen Addict Triathlon Podcast.
Lam Quang Nhat
Swim Coach / Vietnamese National Triathlon Champion
Three-time Vietnam National Triathlon Champion (2023-2025) and former SEA Games gold medalist in swimming (1500m freestyle, 2013 & 2015). Based in Ho Chi Minh City, providing hands-on swim technique coaching.
The Journey
Training Week: Building Momentum (In Progress)
Strong start to the week through Wednesday. Long endurance ride (2h45), pool swims, and a key 75-minute 9/1 run. FTP reduced to 250W to keep bike efforts below LT2. Week still in progress.
FTP Reduced to 250W
Coach Rob and I decided to reduce FTP from 275W to 250W. The goal: keep FTP-based bike sessions ideally below LT2 heart rate of 168 BPM, ensuring sustainable aerobic development without overreaching. Better to build the aerobic engine patiently than chase numbers too early.
Training Week: Steady Rebuilding
Solid return to full training — three runs (24.8km), two bike rides including FTP intervals, four swim sessions, and strength work. Walking volume high at 65km. Aerobic base rebuilding nicely after illness.
HYROX Pro Singapore — Cancelled
Withdrew from HYROX Pro Singapore (early April). The race would have added too much distraction and further compressed an already heavy travel schedule. Decision: full focus on April and May for Da Nang (Challenge Vietnam 70.3) and Roth preparation. Quality over calendar entries.
Training Week: Return from Illness
Full structured training resumed with 50% ramp-up protocol. Key sessions: FTP pyramid test, endurance 9/1 run, swim technique drills. Steady progression back to normal load.
Started GLP-1 — Targeting Race Weight
Started semaglutide (GLP-1 receptor agonist) to reach race weight of 90kg for Challenge Roth. At 100kg+, every kilo matters over 180km on the bike and a full marathon. Strategic weight management to optimize power-to-weight ratio while maintaining training quality.
Garmin Threshold HR Updated to 167 BPM
Garmin auto-detected updated lactate threshold heart rate at 167 BPM (up from 166). Threshold pace remains at 4:48 min/km. Steady aerobic progress during the return-to-training ramp-up after illness.
Training Restart — Back at 50%
Restarted structured training on Monday following the post-illness protocol: start at 50% of normal training intensity and add 10% each day. The gradual ramp-up is working well — no setbacks, body responding positively. A disciplined approach that's paying off.
Niche Biking — TT and Road Bike Check
Visited Niche Biking on Saturday to check out their TT and road bike range. Good news: they can accommodate my height of 196cm — not a given at most bike shops. An important step toward sorting race equipment for Challenge Roth.
Viral Infection — 4 Days Lost
Upper respiratory viral infection with sinus congestion and eardrum pressure. Triggered by long-haul flight combined with staying in sweaty clothes post-exercise. Impacted running, swimming, and strength training. Fully resolved after 4 days — a reminder that recovery hygiene matters as much as training volume.
Training Week: Illness Disruption
Training severely disrupted by upper respiratory infection. Only one run and one ride completed before illness forced a full stop. A forced recovery week — sometimes the body decides for you.
First Garmin Threshold Reading
Garmin auto-assessed initial lactate threshold heart rate at 166 BPM and threshold pace at 4:48 min/km. First baseline markers for tracking aerobic progress through base building.
Z-Coaching Phuket Camp — Cancelled
Planned one-week training camp with Z-Coaching in Phuket — cancelled due to the viral infection. Will reschedule once fully back to full training load.
FTP Updated to 275W
Updated Functional Threshold Power to 275W based on experience from Week 2 Oxygen training sessions. A meaningful jump from the January baseline, reflecting consistent structured training on the bike.
Training Week: Peak Base Volume
Biggest training week so far — over 20 hours. Five bike rides including long endurance sessions totaling 150km+, three swims (6km total), and three runs. The aerobic engine is building serious capacity.
Training Week: Swim Volume Jump
Swim volume ramped up significantly — four sessions totaling 4.6km, the biggest swim week yet. Three bike rides (89km) and four runs (23.5km). Multi-sport consistency improving across all disciplines.
Joined Team Oxygen Addict
Signed up with Coach Rob Wilby's Team Oxygen Addict for structured Ironman coaching. Rob is an Ironman University Certified Coach and 220 Triathlon's Coach of the Year (2019). Having professional guidance is essential for a first Ironman.
FTP Test - Establishing Baseline
Functional Threshold Power test on the bike to establish training zones. This baseline will guide all cycling intensity throughout the program. Critical data for the 180km bike leg.
First Swim Session with Coach Lam
Initial swim assessment with Vietnamese National Triathlon Champion Lam Quang Nhat. Identified technique improvements needed in freestyle: catch phase, body rotation, and breathing rhythm. The weakest discipline gets focused attention.
Training Week: First Big Week
Breakthrough week — 13+ hours of training across all four disciplines. Eight runs (nearly 60km), five rides (97km), three swims, and six strength sessions. The body is adapting to multi-sport load.
Training Week: First Tri-Sport Week
First week with all three triathlon disciplines represented. Five runs (34.5km), three bike rides (57.5km), and first swim session (200m). Strength training continued alongside. The triathlon training plan is taking shape.
Training Week: Running Focus
Heavy running week — seven sessions totaling over 50km. Strength training five times. No cycling or swimming yet as Vietnam relocation was still in progress. Building the run base that will support the Ironman marathon.
Return to Vietnam
Relocated to Ho Chi Minh City to continue base building in a warm climate. Access to pools, roads, and trails year-round.
Training Week: Holiday Maintenance
Reduced volume over the holiday period. Three runs (19km) and two strength sessions. Maintaining consistency through the transition between Germany and Vietnam.
First Brick Workouts
Back-to-back days of bike-run brick workouts. Learning to run on tired legs - the key skill for Ironman. Indoor cycling sessions averaging 60 minutes, followed by 20-35 minute runs.
Base Building Begins
First structured triathlon training session. Indoor cycling (45min, 32km) followed by a 68-minute run in Oberasbach. The Ironman journey officially starts.
Training Week: Ironman Training Starts
First real multi-sport training week. Six runs (31.5km), four bike rides (110km), and four strength sessions. Indoor cycling on the trainer while in Germany. 8.5 hours — the journey begins in earnest.
Training Week: Post-Marathon Recovery
Minimal activity — one easy run (2km), one light ride, and one strength session. Body still recovering from Valencia Marathon. Rest is part of the plan.
Recovery Week in Valencia
Post-marathon recovery with easy walks and light movement. Time to reflect, grieve, and begin planning the next chapter. The decision crystallized: attempt my first Ironman.
Valencia Marathon - In Memory of Rose
Ran 42.2km wearing a custom singlet: "In Loving Memory To You Mom - Your love is my endurance." Finished in 3:51 with her photo on my chest and bib number 40513 named "Rose". This race marked both an ending and a new beginning.
Training Week: Valencia Marathon
The week that started it all — 42.2km at the Valencia Marathon in memory of Rose. One session, one race, one life-changing decision. Everything that follows began here.
Travel to Valencia
Flew from Nuremberg to Valencia for race weekend. Pre-race shakeout run of 5km to test the legs and soak in the atmosphere of the Ciudad de las Artes y las Ciencias.
Final Marathon Preparation in Germany
Training block in Oberasbach and Fürth, Bavaria. Long runs up to 20km while processing grief and preparing mentally for the Valencia Marathon. The running became therapy.
Loss of My Mother, Rose
My mother Rose passed away after a courageous battle. She was 03.05.1945 - 14.11.2025. Her love became my endurance.
Build Phase
Increasing training volume and introducing race-specific intensity. Long rides extending to 4-5 hours, open water swimming practice, and brick workouts becoming longer.
Challenge Vietnam 70.3 - Da Nang
Half-Ironman race as a key B-race. Testing race-day nutrition, pacing strategy, and equipment. A dress rehearsal for Roth at half the distance.
Peak & Taper
Final big training block followed by a 2-3 week taper. Longest sessions completed, now letting the body absorb and sharpen.
Challenge Roth - The Goal
3.8km swim in the Main-Donau-Kanal, 180km bike through the Franconian countryside, 42.2km run with legendary Solarer Berg crowd support. One of the most iconic Ironman-distance races in the world. For Mom.
Training Phases
Learn more about the structured periodization approach I'm following:
Ironman Training Phases Guide Base, Build, Peak, Taper, Race, and Recovery explainedRace Goals
Primary Goal
Cross that finish line. Complete 140.6 miles and become an Ironman. For Mom.
Time Goal
Sub-12 hour finish. Realistic based on current fitness and training trajectory.
Stretch Goal
Qualify for Kona (typically ~10:30 for M45-49 at Roth).