Week 5 prep was a solid step forward. I hit 70.75km, surpassing my 67km target, and nailed back-to-back long runs with London’s rolling trails. A surprising HR drift test reshaped my Zone 2 approach, and daily massage kept a calf niggle in check. Here’s the full recap, plus what’s next as I brace for a wedding-packed Week 6.
Training Breakdown: 70.75km
I aimed for 67km across 5 runs, targeting Zone 2 (now ~150-160 bpm, details below) to build my aerobic base while practicing ultra fueling (200-300 kcal/hr). London’s paths and trails gave me 61m of elevation - a modest but growing step up from Dubai’s flat 3m. An HR drift test showed my aerobic threshold (AeT) is ~165 to ~170 bpm, so I shifted Zone 2 runs to 145-160 bpm, unlocking faster paces. Here’s the week’s breakdown:
- Monday (May 12): Rest day. Strong sleep (7h13m) and HRV (40 ms) set me up well. Form (TSB) at -26, deep in the “getting fit” zone. Read more about TSB here.
- Tuesday (May 13): 8.99km easy run, 7:07 min/km, 136 bpm, 11m gain. London paths, crisp morning. Felt smooth despite calf stiffness. TSB climbed to -17, showing volume’s working.
- Wednesday (May 14): HIIT planned but skipped to focus on calf/ankle recovery. Daily massage and foam rolling loosened it up fast - smart call.
- Thursday (May 15): 12.55km easy run, 6:44 min/km, 140 bpm, 13m gain. Faster than target (7:00 min/km), felt controlled. Short sleep (6h05m) didn’t hold me back. TSB at -7.
- Friday (May 16): 10.03km easy run, 6:26 min/km, 147 bpm, 12m gain. HR drift test day - blown away to find AeT at ~165 bpm, so Zone 2 is now 150-160 bpm. Pushed harder (147 bpm), felt strong despite a mild cold. TSB at -8, VO2 Max up to 46.1. The actual drift test was the middle 6km, keeping pace at 6:00min/km.
- Saturday (May 17): 21.18km long run, 5:57 min/km, 157 bpm, 13m gain. London trails, incredible run. Legs felt solid post-massage. Fueled with 400 kcal, 1000ml water. VO2 Max hit 46.3.
- Sunday (May 18): 18km long run, 5:54 min/km, 158 bpm, 12m gain. Back-to-back long run, 3s/km faster than Saturday. Cardio was effortless, legs a bit sore. Fueled with 400 kcal, 600ml water. TSB at -15, VO2 Max at 46.4.
Total elevation was 61m - small but progress. Back-to-back long runs (39.18km) were the week’s backbone, with paces (5:54-5:57 min/km) crushing Dubai’s 7:00-8:16 min/km. New Salomon shoes arrived, and they've bene great to run this volume in.
Challenges and Wins
Challenges: A calf/ankle niggle early in the week had me cautious, and a mild cold/flu vibe lingered (possibly from travel and/or toddler). Short sleep (6h05m) on Thursday was not ideal but good to test fatigue. Skipping HIIT to prioritise recovery felt like a setback but paid off. I do need to find a way to get some elevation in, so will likely be doing many runs at Richmond in the coming weeks and months.
Wins: Logging 70.75km with 61m elevation is great for Week 5. Back-to-back long runs (21.18km + 18km) at 5:54-5:57 min/km were a breakthrough, and the HR drift test redefined Zone 2 (145-160 bpm), explaining why earlier runs felt too easy. VO2 Max climbed to 46.4 (+4.1 since April), and TSB stayed in the -7 to -26 “getting fit” range. Daily massage squashed the calf issue, letting me add unplanned kilometers.
A Focus on HR Drift and Zone 2
Friday’s HR drift test was a game-changer. Five weeks ago, I pegged Zone 2 at ~140 bpm, but runs felt too easy, and TSB showed I wasn’t pushing enough. The test revealed my AeT is ~165 to ~170bpm bpm, so Zone 2 is now 145-160 bpm. Saturday and Sunday’s long runs at 157-158 bpm confirmed I’m still aerobic, with paces (5:54-5:57 min/km) way ahead of Dubai’s. This sparks questions: how does the shift in aerobic zone fair for progress in the long term? Is it a good thing or would more pace at a lower heart rate be better? I’m diving into books and bouncing ideas off Grok to sort it out. A full post on this is coming. For now, I’ll blend 160 bpm runs with slower 150 bpm sessions to balance speed and endurance.
Looking Ahead: Week 6 and Wedding Awesomeness
Week 6 targets 70km, 5 runs, and a 20km long run, but a friend’s wedding means I need to have some flexibility. I’ll squeeze runs in early or late to hit the volume, but if I fall short, I’ll treat it as a rest week (50-55km) - perfect timing after five weeks of increasing volume. I'll likely add in HR drift tests at four to six week intervals to make sure I am tracking well, and likely need to do a lactate test soon too.
Join the Journey
Week 5 was great - London’s trails are home, and the Zone 2 shift was a welcome surprise. The long runs are feeling increasingly easier and meditative, and those sunrise views in summer are a beautiful bonus. Follow my runs on Strava or updates on Instagram. Check my intro post for the full UTMB 2030 plan.
Happy trails,
Kyle
