Case study · 70.3 and marathon
How Ben Creswick Learned to Hold Back and Ran 2:46 at the Victoria Marathon
"I know i get a bit carried away sometimes lol"
Ben Creswick wrote that under a run that came in faster than planned. On Oct 11, 2026 he ran the Victoria Marathon in 2:46:42, third of 299 in his age group and 33rd of 3,817 overall. Three weeks earlier he was third in his age group at IRONMAN 70.3 Tri Cities. He had been with ANC for seven weeks.
The short answer
How a coach helps a fast athlete run a marathon PR? Angela Naeth Coaching gave each of Ben Creswick's sports its own block, aimed his run at the marathon after his 70.3, and kept the brakes on in training. He ran 2:46:42 at the Victoria Marathon.
In more detail
A fast, fit athlete doesn't need more work. He needs the right work, at the right intensity, in the right order. We gave each sport its own block, turned his run toward the marathon once the 70.3 was done, and kept the brakes on in training so the speed was there on race day.
Then we used the marathon itself to sharpen his numbers, and chose his next block for 70.3 Victoria in May.
Who is this for?
This is for the athlete who already has an engine. You train a lot, you love it, and you tend to go a little harder than the plan says. You want to race more than one big event in a season and race each one well.
If that is you, Ben's seven weeks show how we split the sports, how we set the dose, and why holding back in training is a skill, not a weakness.
Who is Ben?
Fit, and hungry. Ben lives in Victoria, British Columbia. He is a health sciences student, a personal trainer and nutrition coach, and a former soccer player. In his words: "I love to train and take on big challenges."
A full week. He rides to work, studies on a full course load, and fits swim, bike and run around both.
Already training a lot. In the four months before he joined, he ran about 45 to 65 km a week and trained roughly 10 to 16 hours a week across swim, bike and run.
Two races, three weeks apart. IRONMAN 70.3 Tri Cities on Sep 20 was his A race. The Victoria Marathon came three weeks later.
So the question was never whether Ben could work hard. It was whether we could point that work at both races without letting it spill over.
How do you fit a marathon three weeks after a 70.3?
You don't train both sports the same way at the same time. Each sport gets its own block, set by what each race needs.
Sep 1 to Sep 20, race specific for the 70.3. On the bike: race intensity intervals, race specific over/unders and Z1 rides with mid Z2 finishers. On the run: over/unders, race intensity intervals and Z1 long runs with race intensity finishers.
After Tri Cities, the sports split. The run stayed race specific and turned toward the marathon. The bike went back to base and durability work: Z1 rides with LT1 high torque intervals, top Z1 intervals and low Z2 finishers. That kept his aerobic engine ticking while his legs did the marathon work.
More running, on purpose. His running rose from about 45 to 65 km a week before ANC to between about 50 and 90 km a week in the build, with his biggest week, about 90 km, the week after the 70.3. If you want the numbers behind this, read what TSS and weekly training load mean.
The run turned to the marathon while the bike went back to base
He ran more with ANC, peaking at 90 km the week after the 70.3
His weekly load stayed under about 1,000 TSS, then dropped for each race
Why does Ben need a ceiling as much as a floor?
Every zone is a share of his Critical Speed or Critical Power, from his own late August run and bike efforts. That gives every session a floor and a ceiling.
Ben's challenge was the ceiling. Again and again his easy and steady work came in hot. Angela's notes from those weeks:
- "A little faster than intended."
- "On a hilly route, the main thing is not letting the rises turn the whole ride into a hard day."
- "We need to keep some reins on you."
- "We are hitting very specific zones physiologically. Save it for race day!"
Why it matters. A Z1 run done in Z2 isn't a bonus. It's extra fatigue that steals quality from the next key session. Each zone has a job, and the job only gets done inside the zone.
He learned fast. By mid September he wrote: "I made sure to stay on the slower side of my race pace on the intervals! Feeling good!"
Why read heart rate with pace, power and feel?
Pace and power show what Ben produced. Heart rate shows what it cost him that day. Feel ties them together.
Indoors on the bike, his effort felt higher than the watts suggested. Angela read the heart rate against the power and asked about the room. It was much warmer inside. The fix was a fan, not a zone change.
Hilly routes pushed his pace around, so on those days we leaned on effort and power, with heart rate as the cross check. More on this in how we set heart rate zones.
What did the key sessions look like?
Race intensity intervals. Repeats at marathon effort with easy running between, so goal pace becomes familiar rather than frightening.
Z1 long runs with race intensity finishers. The big one came on Sep 27: 34 km in about 2 hours 20, most of it on the marathon course. "Intervals were tough at the end legs were feeling it but still felt in control." He fuelled with a 120 g carb breakfast and 60 g of carbs an hour during. Angela's reply: "That's exactly the kind of long practice."
How did the 70.3 go?
Third in his age group, 13th overall. Ben raced Tri Cities on Sep 20, three weeks before the marathon.
On pace. At Tri Cities on Sep 20 he rode at about 85% of his CP by normalized power and ran the half marathon at about 87% of his Critical Speed. Angela's note on his run: "This was fantastic ... executed right on pace."
Then recovery came first. His next runs were easy, and by Sep 22 he wrote: "legs seemingly have bounced back well."
Ben's 2026 races
How did he race Victoria?
Fresh legs on race morning. His run form sat at about plus 16, with fitness near 49. He was rested and still fit.
A strong, steady day. He ran 2:46:42 on chip time, about 3:57 per kilometre, to finish third of 299 in his age group and 33rd of 3,817. Three weeks after his 70.3 and seven weeks into coaching, that is a big day on any measure.
He started the marathon fresh, with run form at plus 16
What did the marathon teach us?
A race is the best test there is. We use it.
The numbers. For an open marathon we use 85% to 90% of Critical Speed. His September Critical Speed came from short, sharp efforts, and his marathon told us what he can hold for hours.
So we reset his run anchor. We moved his Critical Speed to about 5:32 per mile, about 3:26 per kilometre. Against that number his marathon sat at about 88%, right in the window. His run zones now come from the number that matches race day.
Why did we choose each block?
Every block answers one question: what does this athlete need most, given his numbers, his races and his calendar?
Our decision order is the same for everyone: anything that overrides, then the timeline, then the ratio between Critical Speed and the speed he can hold for a hard 800, then his limiter, recent history and readiness.
Race specific for the 70.3. His Critical Speed sat at about 87% of his 800 speed. That is a balanced profile: neither short on aerobic engine nor short on top end.
So what limited him? For a balanced athlete, the question becomes what limits him. Ben had plenty of fitness and he loved to train, so the limiter was execution, holding the right effort for the whole race. Add the timeline, with his A race six weeks away, and every rule points the same way: Specificity.
Splitting the sports after Tri Cities. The marathon was a run race three weeks out, so the run stayed specific. The bike had no race for eight months. Race intensity bike work then would have added fatigue to his legs with nothing to aim at, so the bike went back to base. Two races, two needs, two blocks.
The run kept its marathon focus. Long runs at Z1 with race intensity finishers, over/unders and race pace intervals, all at marathon effort, not 70.3 effort. That gave his legs the specific durability a 42 km day asks for.
Base and durability now, in both sports. Three things point here.
The timeline and the floor. 70.3 Victoria is about 30 weeks away, the time to build an engine, not to sharpen it. The floor: we don't start harder blocks while bike fitness sits under 45, and his was 43 on Oct 30 after a month of run focus.
The limiter. His reset Critical Speed shows his long range durability is what to build next. Ben put it well in his own post about his first week back: "A bigger engine, more durability, and a higher ceiling for the hard work later."
The five weekly calls. Inside a block, each sport gets one of five calls every week: increase by a lot, increase by a little, hold steady, decrease by a little, or decrease by a lot. The week after Victoria was a decrease by a lot, pure recovery.
Coming back to structure was an increase. From here we build fitness at a steady ramp and keep weekly hours within about 20% of the week before, with a lighter week built in.
Bike fitness sat just under our base floor, so base came next
What is Ben looking toward?
His goals, in his words. He wants to win his age group at IRONMAN 70.3 Victoria in May ("I'd be happy with top 3"), and podium and qualify for Kona at his first IRONMAN in August. He also wants to keep a decent GPA.
A winter of short races. A Harrier Pioneer 8K on Jan 10, the Cobble Hill 10K on Jan 24, the Comox Valley Half Marathon on Mar 21 and the Bazan Bay 5K on Apr 11. Each one is a check on run fitness, and each one updates his numbers the way Victoria did.
Two A races. IRONMAN 70.3 Victoria on May 30, 2027, at home, and IRONMAN Canada in Ottawa on Aug 8, 2027. The blocks between now and May will be chosen the same way as these ones: read the numbers, then pick.
Where he is now. His first week back was 15 hours, 19 sessions and 272 km, mostly Z1 with short pick ups. His own words after a strong session: "Bike fitness is feeling GREAT."
Base now, short run races in winter, two A races next summer
How ANC coaches
Coach led, every week. Every ANC coach is educated in one shared ANC method covering physiology, zones, block selection and weekly load, and brings their own experience and judgment to you.
StressLogic. We Evaluate who you are and how you respond. We Calibrate the right intensity, volume and recovery. We Harmonize training with school, work, racing and recovery. We Optimize as you change, including resetting numbers after a race. Your physiology sets the direction. Your life sets the dose.
Your numbers, not a chart. Zones come from your own Critical Speed and Critical Power. Heart rate is always read with power, pace and feel.
Never a template. Two races three weeks apart got two different plans, sport by sport. You learn why every number exists, so you can own your decisions.
Takeaways for you
- Respect the ceiling of every zone. Easy done hard is just fatigue.
- Give each sport its own block when your races ask for different things.
- Rehearse race fuelling on your long sessions.
- Use every race as a test, and let it update your numbers.
- Choose each block from your numbers, your races and your calendar, in that order.
FAQ
Can you race a marathon three weeks after a 70.3?
Yes, if the plan is built for both. Ben's run stayed race specific through both races while his bike went back to base, and he started the marathon rested.
Why go back to base after a great race?
Because the next A race is months away. Base and durability build the engine that the later, harder blocks use. Sharpening too early leaves nothing to sharpen.
What does a marathon tell you about your numbers?
It tells you what you can hold for hours. Ben's race let us reset his Critical Speed to a number that matches race day, and his zones now come from it.
Your engine deserves a plan that steers it
Ben didn't need more motivation. He needed numbers that told the truth, a ceiling on his easy days, and a coach who used every race to sharpen the next plan. Read how Katy Walmsley ran a Boston PR with no extra hours for a very different marathon build, and see how we analyze a race to set up the next one.
Tell us about your races and your week, and we'll show you how coaching would work for you.