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.
Race-specific build phase — longer sustained efforts, race-pace work, and progressive volume increases toward Challenge Roth. Currently recovering from third cold and establishing indoor trainer setup (Wahoo KICKR Core). 52 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
DATEV Confirms Roth 2026 Cancellation — 2027 Entry Cleared
The official cancellation email from DATEV landed today: 'Your participation in DATEV Challenge Roth 2026 is cancelled now.' The upside — with the 2026 entry formally closed, I'm now allowed to enter for Challenge Roth 2027, and I will. Race day: Sunday, July 4, 2027. Coach Rob, the training plan, and the recovery roadmap all carry over to the rebuilt 14-month build.
Crash — Right Femur Fracture, Surgery Same Day
First outdoor ride on the rental Cannondale. Reaching down for the aero bars at ~15:00 ICT, the bike swerved and I fell laterally onto my right hip. Right femur subtrochanteric fracture, comminuted at the proximal end. Same-day surgery at BVDK Tam Anh HCMC: cephalomedullary intramedullary nail (PFNA/TFN-style), titanium hardware (MRI-safe, confirmed by BS Lưu), cephalic lag screw plus distal interlock. Now Day 17 post-op — sutures out, NWB on the right leg through May 19, home PT Phase 2 (sit/stand/walk plus groin abduction), Rivaroxaban 10mg daily for DVT prophylaxis, pain controlled on Celecoxib + Ultracet + Gabapentin. Race impact: Da Nang 70.3 (May 10) cancelled. Challenge Roth 2026 cancelled — registration transferred to Roth 2027 (Sunday, July 4, 2027) this week. Valencia Marathon (Dec 6) stays TBD until the 10–12 week follow-up. NSFW accident footage may follow if we recover it — see the warning above this timeline.
Bike Fitting #2 — Cannondale at ChinPho Cycle Vietnam
Second bike fitting session at ChinPho Cycle Vietnam — the same shop that did the initial IDmatch profile and fitting on March 30. This time on the 61cm Cannondale SuperSix EVO rental bike, but still without proper cycling shoes (none secured yet in size 49). Already feels noticeably better than the first session, but we both agreed the max stack height of the Copilot stem is still too low for a 196cm rider on this frame. Not ideal, but workable for Da Nang. The right shoes and a taller stack will be the next pieces to sort out.
Race Bike Secured — Cannondale SuperSix EVO for Da Nang 70.3
Finally locked in a 61cm road bike for Challenge Vietnam 70.3 on May 10. Renting a Cannondale SuperSix EVO (if AI-based frame identification can be trusted) from Bike Station in Saigon — the only shop in HCMC with frames big enough for a 196cm rider. Two rental periods covering March 20 through May 12 ($314 USD), plus transport HCM to Da Nang and back ($59 USD). Total: $373 USD. The convenience factor is huge — they handle delivery to Da Nang and pickup after the race. Clip-on aero bars will go on for race day, following Coach Rob's advice: road bike with clip-ons over a TT bike for the 19-week timeline.
First Proper Run Test — HR 162, 5:37/km
45-minute run test on the treadmill at 0% incline. HR averaged 162 BPM at 5:37/km pace. Coach Rob confirmed: 'HR sits right at the bottom of Z4 for the second half — probably perfect intensity.' Three false starts calibrating the Technogym Run Excite 1000 before getting it dialed. A key data point for refining run training zones. One notable feeling: 5:37/km felt sluggish and the effort felt high — not what those numbers suggest outdoors. These Technogym treadmills seem to run comparably slow; the same perceived effort outside would put me well under 5:00/km.
Aero Bar Clamps Upgraded — Heavy-Duty for 90kg Rider
After a few sessions on the aero bars, it became clear the standard clamps that came with the rental bike weren't strong enough to hold my weight when leaning into the aero position. Tuna Tri Hub in Saigon had flagged this might be an issue from the start. Upgraded to heavy-duty clamps with wider pads and stronger grip — $98 USD (2.5M VND) for parts and installation. A necessary fix before putting serious miles on the aero bars heading into Da Nang 70.3.
First Trainer Session — No ERG Mode
First structured session on the KICKR Core: KEY SweetSpot 2x20 at 85-95% FTP. Key coaching directive from Rob: avoid ERG mode entirely, even for structured intervals. ERG removes the need to actively manage power — a critical racing skill. Resistance or slope mode for everything. Garmin Rally power pedals confirmed as the primary power source over the trainer's built-in reading for consistency across indoor and outdoor rides.
Training Week: Return from Third Cold
Return to training after the third cold. Apr 5: pool swim and gym strength. Apr 6: KEY 9/1 endurance run (8km, HR 142). Apr 7: recovery ride on the new KICKR Core, strength, and a second run test (6.5km, HR 159). Apr 8: KEY SweetSpot 2x20 on trainer plus a pool swim. Apr 9: KEY run test — 60 min at 5:37/km, HR 157 avg. Three runs, two rides, two swims in the back half of the week. TSS rebuilding.
Third Cold in Three Months — Pattern Emerging
Another upper respiratory infection, the third since starting Ironman training. Triggered by heavy loading at the end of the prior week (long ride + open water swim + swim sessions + FTP test) followed by a 3-hour pickleball session in sweaty clothes with aggressive air conditioning. Retrospectively, the warning signs were visible: night HRV was declining and resting HR was rising before symptom onset. Coach Rob's assessment: recurring infections point to something systemic — recovery, sleep, stress — rather than needing more supplements. Key learning: monitor HRV trend and resting HR daily, and reduce training load proactively when both deteriorate, before getting sick.
Wahoo KICKR Core 2 Purchased — $708 USD
Ordered the Wahoo KICKR Core 2 Smart Trainer from RiDE+ (rideplus.vn) for 17,500,000 VND ($689 USD), plus a Saris Climbing Riser Block for the front wheel at 490,000 VND ($19 USD). Total: $708 USD delivered. Trainer arrived April 1, front wheel holder the next day. At only about 40% more than the used older-generation Tacx and KICKR models floating around Saigon, buying new felt like the right call — warranty, current firmware, and no mystery wear on the resistance unit. Coach Rob had recommended the KICKR Core over the Tacx Flux S and advised skipping the KICKR ROLLR entirely. Combined with the Garmin Rally power pedals, this creates a consistent indoor/outdoor power ecosystem.
Training Week: Heavy Load → Cold #3
Mar 29 was the heaviest single day of training in the entire Ironman journey: a 3h20 KEY endurance/strength ride (TSS 163) plus a 1.1km pool swim. Then the cold hit Mar 30 and training stopped dead. The rest of the week was walks only. The pattern is clear: massive loading day → immune crash within 24 hours.
First Open Water Swim
First open water swim of the Ironman journey. A critical milestone — pool swimming and open water are completely different beasts. Sighting, currents, wetsuit feel, and the mental shift from black-line comfort to open-water uncertainty. Challenge Roth starts with a 3.8km swim in the Main-Donau-Kanal.
Training Week: First Build Week — Biggest Run Yet
First full week of race build. Four bike sessions (69km endurance ride, cadence drills, FTP test at 281W, cycling commute). Three runs including the longest of the entire journey — a 1h45 KEY 9/1 endurance run covering 16.7km. Three pool swims including two 1.1km sessions. Three strength sessions and two yoga sessions. Highest TSS week of build phase so far.
GLP-1 Taper Begins — 5 Weeks Full Dose Complete
Completed 5 weeks at full dose (30 clicks/week). Results: weight 94.5→89.0kg (week 5 low), waist -2cm, belly -3.5cm. FTP 261→281W (+7.7%), W/kg crossed 3.0 for the first time. Zero missed sessions, zero side effects after switching to evening injections. Blood work: HbA1c 5.30%, HOMA-IR 0.59, testosterone 989 ng/dL. Now entering taper: 20 clicks/week for 2 weeks, then 15 clicks/week until last injection April 24 — giving 16 days washout before IM 70.3 Da Nang. Post-race: resume at 15 clicks/week low-dose maintenance through Challenge Roth. <a href='/en/training/nutrition/glp1/'>Full protocol</a>.
Indoor FTP Test — 296W Average, New FTP 281W
20-minute FTP test on a Technogym Excite 1000 gym bike. Averaged 296W at 93 RPM, yielding a new indoor FTP of 281W (95% of 296W). At 90.2kg (weigh-in Mar 29), that's 3.12 W/kg — up from 2.76 W/kg at the start of the GLP-1 protocol (+10.1%). The combined effect of weight loss and fitness gains is compounding: lighter body, stronger engine.
Clip-On Aero Bars Installed — Profile Design, Size L
Had Profile Design clip-on aero bars (size L) installed on the rental bike at Bike Station Saigon. A step up from basic clip-ons — these are properly adjustable for arm pad width, extension length, and angle. The key advantage: they transfer directly to any road bike, so when the Cannondale XL arrives for Da Nang 70.3, the aero position carries over with zero refitting. Coach Rob's philosophy: road bike with clip-ons gets you 80-90% of a TT bike's aero benefit, with far more versatility for the 19-week timeline.
Base Phase Complete — Race Build Begins
Officially transitioned from base building to race-specific build phase after 13 weeks of aerobic development. Build phase focuses on longer sustained efforts, more race-pace work, and progressive volume increases toward Challenge Roth. Marked by the first 1h45 endurance run — the longest continuous run since training began.
Training Week: Singapore & Travel Deload
Final week of base phase, with sessions split between Singapore and Ho Chi Minh City. Key 75-minute 9/1 endurance run in Singapore. Two indoor bike sessions and two swim sessions. Lower overall volume — a natural deload before the transition to build phase.
Singapore — Boat Quay
Three nights at Cube Social capsule hotel in Boat Quay. Key 75-minute endurance run along Marina Bay, two indoor bike sessions at a nearby gym, and a pool swim. Quick stopover en route back to HCMC from Western Australia.
Training Week: Western Australia Running Block
Traveled to Perth and Busselton in Western Australia — excellent running conditions. Four runs totaling 35km, the highest run volume in weeks, including a key 75-minute 9/1 endurance run. Three bike sessions (two indoor on trainer, one outdoor SweetSpot 2x20). Five swim sessions across three days. Consistent high-quality base building.
Western Australia — Perth & Busselton
Week-long training block in Western Australia. Two nights in Perth (Doubleview) followed by five nights in Busselton (Geographe Holiday Homes). Excellent outdoor running conditions and pool access. Key 9/1 endurance run in Perth, easy-pace runs along the Busselton coast.
Training Week: Peak Base Volume
Biggest volume week of base training. Four bike sessions totaling 207km, anchored by a 3-hour endurance ride with hills (97km). Two runs including a key 75-minute 9/1 session. Four swim sessions. FTP reduced to 250W to keep bike efforts below LT2 heart rate.
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 Tirzepatide (GLP-1) — Targeting Race Weight
Started tirzepatide (Mounjaro) at 2.5mg/week (30 clicks, half pen) — the lowest available dose, injected Friday evenings. Targeted intervention to break the Ironman hunger cycle: 15-20 hour training weeks were driving massive appetite, chronic overeating, and weight oscillation between 89-95kg. Lifelong sugar sensitivity and emotional eating made this cycle particularly hard to manage through willpower alone. Plan: 5 weeks at full dose, then taper down through race prep, with low-dose maintenance during peak training. Goal: reach 90kg race weight while preserving muscle mass through high protein (140-190g/day) and maintained resistance training. <a href='/en/training/nutrition/glp1/'>Full GLP-1 protocol</a>.
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.
Bangkok — Thong Lor
Three nights at Hotel Walton Suites in Thong Lor, Bangkok. Training restart after illness with gradual 50% ramp-up protocol. Short trip between illness recovery and return to HCMC base.
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. Previously running a ChatGPT-generated training plan — effective for getting started, but not sufficient for a first Ironman. Rob is an Ironman University Certified Coach and 220 Triathlon's Coach of the Year (2019).
Initial FTP Estimate — 275W
Set initial FTP at 275W using an online calculator estimate — no formal test. At 96kg starting weight, that's 2.86 W/kg. This baseline guided cycling zones through the first six weeks of base training until the March 4 reduction to 250W.
InBody Scan — Baseline Body Composition
InBody body composition scan to establish baseline: 94.1kg total weight, 50.9kg skeletal muscle mass, BMR 2,271 kcal. This becomes the reference point for tracking the impact of training load and the GLP-1 protocol on body composition through to race day.
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.
Starting Weight — 96kg
First body measurement of the Ironman journey: 96kg at 13.5% body fat. Race weight target: 90kg for Challenge Roth. Every kilogram matters over 180km on the bike and a full marathon. Weight management will run parallel to training through the entire preparation.
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 C-race. Testing race-day nutrition, pacing strategy, and equipment in tropical conditions. A dress rehearsal for Roth at half the distance — swim 1.9km, bike 90km, run 21.1km.
Taper Begins — 2 Weeks to Roth
Final big training block completed. Two-week taper leading into Challenge Roth. Volume drops significantly while intensity stays sharp. The body absorbs months of accumulated training load.
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).
Following Along? I'd Love to Hear From You
Whether you have questions about the training, suggestions for the journey, or just want to share your own Ironman story — drop me a line.