This post is split in two:
- Story and progression
- New tactics that I believe helped me go sub-3
If you’re here for the tactics, click here to jump down. Otherwise, keep reading…
I remember signing up for my first marathon – Athens – back in 2019 and thinking:
“I can run a half marathon in 1h25…
How hard can it be to run a full marathon in 3 hours?”
Turns out it’s pretty damn hard.
I blew up at the 25km mark in Athens that year, finishing the first half in 1h32 and the second half in a painful 2h5, coming in at 3h37.
I returned to the UK feeling a wee bit sheepish.
And so began my dogged pursuit of the elusive sub-3 marathon.
Two years later, I ran London Marathon. The race was two months after my first Ironman, so I spent the lead-up mostly recovering from the Ironman and doing very little marathon-specific prep.
I wasn’t aiming for sub-3 in this race. I simply ran for enjoyment, and had one of the most joyful mornings of my life.
From a performance point of view, this marathon was less disastrous. First half in 1h34, didn’t fade until the 35km mark, and finished in 3h15.
Respectable, and not bad considering I’d just moved flat, been drunk at a friend’s 30th two nights before, and slept on a camping mat the night before the race.
Third Time Lucky
2022 was the year of Ironman Wales, and the biggest year of my life so far in terms of training volume. I was determined to run a sub-3 in the first half of the year, so that I could put this damn target to rest and focus on the Ironman.
In February, I ran a new 10k PB of 37:17.
In March, I ran a new Half Marathon PB of 1:20:48.
All the race calculators were predicting I could run a full marathon in 2h56, so I felt confident going into Paris Marathon in April 2022.
Ran the first half in 1:27:50. Excellent! Well on track for sub-3. What could go wrong…?
I started to experience some pain in my foot, and the inevitable Marathon Fade kicked in at the 22km mark. I’d switched to some new carbon shoes (Alphaflys) just a few weeks before the race, and they gave me a mega blister on race day.
Lesson: don’t run a marathon in shoes you haven’t done your training in. (More lessons here: 6 Lessons Learned from Paris Marathon)
Bagged a PB of 3:09:00 but didn’t get the result I had hoped for, and left Paris feeling un peu déçu.
I took a break from marathons for a couple of years after that.
Finished the Ironman in September, spent 2023 resolving some health issues that prevented me from training consistently, and came into 2024 without any clear goals.
I decided to race Milan Marathon in April 2024, but only signed up in late January, so didn’t have a huge amount of time to prepare. Two days before the marathon, as I tried to board the plane, I was prevented from boarding because my passport had less than six months remaining until expiry (f*cking Brexit…) and had to quickly switch to Brighton Marathon.
I knew I wasn’t in sub-3 form, so set out with an intention to run a PB. I was returning to form after a year away from structured training, so I’d have been happy even if I only shaved one second off my Paris time. Progress is progress.
Set out at a slightly-too-hot pace, ran the first half in 1h31, then clung on for dear life as The Fade kicked in again. Bagged a new PB of 3:08:28.
Although I faded in the second half, the magnitude of the fade had been lower than previous race.
| Race | Fastest Km | Slowest Km | Δ Difference |
| Athens | 4:05 | 7:16 | 3:09 |
| London | 4:14 | 5:21 | 1:07 |
| Paris | 4:03 | 5:12 | 1:09 |
| Brighton | 4:06 | 4:48 | 0:42 |
My strength and endurance were improving, and I knew that sub-3 was within reach if I gave it some focused attention…
Valencia
2024 has been a great year for endurance sport, optimised mostly around fun.
I ran Brighton in April, then took a 2-month sabbatical from work that involved a lot of running, a solo mountain marathon in Hakone (Japan), some big bike rides in the mountains surrounding Osaka and Seoul, and bikepacking the North Coast 500 in seven days.
The only race in my calendar was the two-day OMM (Original Mountain Marathon) in October 2024, so I spent most of my training sessions building strength and stamina for that.
Then, in September, a friend who was injured offered me his place at Valencia Marathon.
This felt serendipitous. I was on good form and had spent most of my year building my base long-distance endurance.
Could this finally be my chance to go sub-3?
Training for Valencia
My weekly mileage for Valencia was the highest of my last three marathons, peaking at 69km a month before the race.
Every Sunday, I’d do a long run with Marathon Race Pace efforts, such as 2x 6km or 2x 8km. I had wanted to run a 34km long run in training, but only peaked at 30km.
My consistency suffered a couple of months before the race due to travel and moving flat, but I had a solid four-week block in Berlin just before the race and will forever cherish those long runs around Tiergarten.
You can see from the graph above that my training for Valencia involved a lot more volume than Brighton or Paris. Across the 12 weeks before race week, I averaged:
- Paris: 35km per week
- Brighton: 33km per week
- Valencia: 46km per week (31% more than Paris)
Overall Training Stress Score, which accounts for cycling and other sports, was relatively stable in the three months before Valencia, with a spike at the -8 week mark when I spent a week cycling around the mountains in Mallorca.
12-week averages:
- Paris (with Ironman training): 602
- Brighton: 393
- Valencia: 493
Race Day
Apart from arriving at the start line late and getting stuck in the 3h15 – 3h30 group, everything else on race day went exactly to plan.
The Valencia course is stunning, with great support along the entire course and no hills in sight, so pacing strategy didn’t require any adjustment for elevation changes.
I had read in Advanced Marathoning that it’s natural for the second half of a well-run marathon to be 2-4% slower then the first half, so after a hectic first warmup kilometre moving through crowds of slower runners, I settled into 4:11 pace.
The 2-4% slowdown turned out to be bang on, as I came through the first half in 1:28:42 and the second half 2.9% slower in 1:30:36.
This was my best-paced marathon by far, with only a 19-second difference between my fastest kilometre of 4:07 and a slowest of 4:26.
Finally, everything had come together on race day. The whole race felt great until around 33km when I had to grit my teeth and fight through the fade. 38km was my slowest kilometre, and at this point I started to doubt whether I’d still be able to go sub-3…
Thankfully, I found some energy reserves in me and pushed on to hit 2:59:17, which felt incredible and slightly surreal. I almost cried as I approached the finish line and saw the clock ticking through 2:59:17.
Finally.
So, beyond simply running more miles in training, what do I think led to this personal breakout performance?
Nutrition
Nailing my nutrition played a big role in going sub-3.
Specifically, I did five things differently for Valencia:
- Higher Carb Loading
- More gels during the race
- Caffeine gum
- Nitrate loading
- β-Alanine loading
Higher Carb Loading
I decided to read up on proper carb loading before Valencia, and discovered that runners should aim for 6g-10g of carb per kg of bodyweight in the days leading up to a marathon. For me, at 68kg, this was between 408g and 680g of carbs.
For Valencia, I decided to track all the food I was eating in the week leading up to the race in MyFitnessPal, something I hadn’t done for previous races. It turns out getting enough carbs in race week was surprisingly difficult, and I learned that I definitely hadn’t been carb loading sufficiently for previous races.
My carb intake during race week was:
- Monday: 300g
- Tuesday: 350g
- Wednesday: didn’t track
- Thursday: 300g
- Friday: 380g
- Saturday: 400g
Even armed with the knowledge that I should be aiming for 400-700g, I struggled to eat more than 400g. This is something I’ll be experimenting with during my next race.
More gels during the race
I had been running with Maurten gels for the last couple of years, as it seemed to be the only gel that agreed with my stomach, but resented how much they cost.
This year, I started experimenting with Precision Hydration’s PH30 gels. About half the price of Maurten, and didn’t cause me any gastric issues at all.
I relied on these a lot in training, and used long runs as a chance to practice having three gels in a single session. These gels were having a noticeable impact on my energy levels; within about 15 minutes of consuming one, I’d start to feel less tired and more energetic.
I had five gels on race day, alternating between PH30 gels and Maurten Caffeine gels with 25g of carb. I hadn’t trained with the Maurtens, so found the jelly-like consistency quite offputting during the race. I’m switching to PH30 Caf for future races.
This was the first race that I was able to stomach five gels without feeling bloated, and I actually wished I’d had a sixth one for the final few kilometres!
Caffeine gum
One of the problems with taking on caffeine in gel form is that it requires digestion. Sometimes, you want the kick without actually having to eat anything.
We were given caffeine chewing gum in our race packs at the expo, but I had no intention of using them during the race. “Nothing New On Race Day”
That is, until I saw my coach for dinner and he told me he’d tried the chewing gum, it was ridiculously strong, and he intended to use it.
I packed a few in my race belt, and decided I’d try one out around the halfway point.
At 22km, I popped one in and almost immediately felt a rush of caffeine hit me. The beauty of this was that it required no digestion, so I had several during the second half of the race without causing myself any gastric distress. Will be using these again!
Nitrate Loading
Research has shown that drinking beetroot juice can improve endurance and performance on race day:
Several studies have demonstrated positive effects of beetroot juice supplementation on running performance:
- A study involving recreationally fit individuals found that consuming baked beetroot (200g with ≥500 mg nitrate) 75 minutes before a 5-km treadmill time trial resulted in a 5% faster running velocity during the last 1.8 km of the run1
- Research published in the Journal of Applied Physiology reported that runners who took a beetroot juice shot before racing reduced their 5km race times by 1.5%2.
- A large systematic review of 80 clinical trials found that beetroot juice consumption provided performance benefits for athletes, with improvements equivalent to 48 seconds in a 16.1 km cycling time trial3.
The performance benefits of beetroot juice are attributed to its high nitrate content, which leads to increased nitric oxide availability in the body. This has several physiological effects:
- Improved exercise economy: Studies consistently show that beetroot juice supplementation can reduce the oxygen cost of exercise, making athletes more metabolically efficient at a cellular level4.
- Enhanced muscle oxygenation: Research has observed improvements in vastus lateralis oxygen saturation (SmO2) after beetroot juice supplementation5
- Increased time to exhaustion: A study with elite middle and long-distance runners found that 15 days of nitrate-rich beetroot juice supplementation produced substantial improvements in time to exhaustion during an incremental treadmill test5
Long story short:
I bought a lot of beetroot juice, and drank about 400ml every day for two weeks. I am a sample size of one and I have no data to back this up, but I think it helped.
β-Alanine Loading
I was reading up on Creatine supplementation in November, and was surprised to come across some marathoners using it. I had previously thought it was only for bodybuilders.
In my reading, I then came across a supplement I’d never heard of before called β–Alanine. In short:
Beta-alanine supplementation increases muscle carnosine content, which acts as an intracellular pH buffer. This mechanism helps reduce muscle acidity during high-intensity exercise, potentially delaying fatigue and improving performance1.
Time to Exhaustion:
- Studies have consistently shown that beta-alanine supplementation can increase time to exhaustion in high-intensity exercise2.
- Improvements of 12-16% in cycling time to exhaustion at 110% of maximum power output have been reported after 4-10 weeks of supplementation3.
Endurance Performance:
- Beta-alanine has shown modest but potentially worthwhile benefits for endurance events lasting longer than 4 minutes1.
- A meta-analysis found that beta-alanine supplementation improved exercise capacity in tasks lasting 60-240 seconds and beyond 240 seconds4.
Running performance:
- A study on 10-km running performance showed significant improvements with beta-alanine supplementation, with runners completing the distance faster and exhibiting lower blood lactate concentrations5.
The majority of studies were showing benefits to short bursts of intense speed, but there were some promising signals indicating that it might aid longer distance endurance and delay fatigue, so I decided to start taking 4g every day in the two weeks leading up to race day. Not long enough to see a huge difference, but I thought it was worth a go.
On training days, I’d take it 10 minutes before heading out on my run, and I felt noticeably stronger during my hard interval sessions. I had some on race day, too.
Again, I’m a sample size of one, and it could have been a placebo effect, but I think it helped me execute stronger interval sessions, and I’m confident it helped me run faster on race day.
I use Bulk’s Beta-Alanine powder, which is currently £20 for 1kg – enough to last 250 days.
Use my code for 45% off: https://mention-me.com/m/ol/zk5eg-james-mcaulay
So there we have it. Everything that I believe helped me dip below the 3-hour barrier.
I hope this has been vaguely educational, and if you’re aiming to go under 3 hours for the first time, I hope some of these tactics help you get there.
After five of years of trying, I can tell you this with certainty:
breaking the 3-hour barrier is a target worth chasing.