Running a Sub-3 Hour Marathon and Qualifying for Boston

@January 20, 2020

Last year, I decided to give the marathon another shot and signed up for the California International Marathon in December. I ran my last (and first) marathon in 2015, and it hadn’t gone well. It took me almost 5 hours to finish and I ended up walking the last few miles. Admittedly, I hadn’t taken training very seriously. My goal in 2015 was just to finish, and I realized later in the training cycle that that’s not a very motivational goal. Around 90% of people who start a marathon finish. Once I convinced myself I had the base level of fitness to do it, I slacked off.

This time around, I wanted to take training seriously and see how much I could improve. My base level of fitness wasn’t terrible having ridden the Sea Otter Gran Fondo (a 100-mile bike race) in April. Training for that involved cycling around 100 miles a week for a couple of months, but I was barely running at all. I had a run a total of 83 miles in all of 2018, essentially nothing. I knew that I couldn’t just limit myself to a typical marathon training cycle if I wanted a substantial improvement. I planned to slowly work up in mileage so that by the time the training cycle came, I’d be ready with a decent level of running fitness.

Around this time, I listened to an old podcast on Trail Runner Nation called Speed up by slowing down with Dr. Phil Maffetone. A key point of his changed my perspective. I won’t go into the details of Phil’s method here, but I realized that I was pushing myself to run too fast in training. I did this for several bad reasons: a fixed idea of the pace I “ought” to be running at. Wanting to impress my friends on Strava. Feeling like my runs were a waste if I wasn’t exhausted afterward.

So starting in May, I made the decision to slow down and give heart-rate training a try. My full training took place in two parts:

  • Part I, May 13-Aug 4 (12 weeks): Building a base with heart-rate training
  • Part II, Aug 5-Dec 8 (18 weeks): Official marathon training cycle

During Part I, I ran about five times a week, with four runs fixed at 150BPM and one run at steady-state (a bit faster). For me, this started around a 9-9:30 min/mile pace. I can’t say for sure if this specific style of training was the key, but after 12 weeks I noticed two big results:

  1. I was able to run at 150BPM with an 8-8:30 min/mile pace.
  2. Forcing myself to run slowly helped me finally enjoy running. I felt like I could actually pay attention to scenery, listen to podcasts, or talk to friends I was running with. This made getting in the volume so much easier — at last, running wasn’t just pain. I looked forward to most of training runs.

On July 28, near the end of Part I, I ran the San Francisco Half Marathon. My previous personal best was a 1:52, which I had run eight years prior in 2011. This time around, with my sole focus on heart-rate training, I had no idea how fast I could run. On race day I thought I could hold an 8 minute pace, but against all conventional wisdom, I went out fast and decided to try and hold it. I ended up running a 01:35:04 (7:15 pace), with a negative split. This was a very exciting improvement!

It wasn’t until the Urban Cow Half Marathon in October, with just two months of training left, that I started to set my sights on running under 3 hours and qualifying for Boston. I ran a 01:27:06 (6:36 pace), a huge improvement from my 1:35 in July. After the race, folks told me that they had run worse times at Urban Cow the previous year, and still went on to run under 3 hours in December at CIM. I still had doubts. A 1:27 half is only a 2:54 marathon, I felt like I had given everything just to hold that pace for a half.

However, in the following weeks in training, I was able to push my marathon pace in workouts down to a 6:50min/mile. The final long run workout was a 20-mile run, three works before the marathon. It consisted of 9 miles at 6:50 (marathon pace). Ready or not, the race was quickly approaching.

The race

Believing I had the fitness to finish around three hours, I worried a lot about what precise pace would safely make the Boston cut-off. While a 6:50 pace (a 2:59:10) is fast enough for an official submission, it would not have been fast enough to be accepted in 2020 (which required a finishing time 1 minute and 39 seconds below the listed times, a 2:58:21). To be safe, I decide to shoot for a 6:45 pace — a 2:57 finishing time.

Just behind the seeded corral, I found a group of people that were also shooting for under 3 hours. We made a quick pact to stick together throughout the race. Feeling a bit of pressure from this group, I again started too quickly with a 6:21, a 6:38, and a 6:25 over the first three miles. However, I deliberately backed off after that, and was able to stay between 6:37 and 6:47 for miles 4-18 (with the exception of a 6:33 on mile 11, which is mostly downhill). I barely felt tired at the half marathon point, which came as a shock because the pace was similar to my half marathon PR just a few months earlier.

Things started to go south at Mile 19. I ran a 6:54, the slowest mile of my race. Someone I had stuck beside from the starting line decided to drop out. At mile 20, CIM puts up a big tarp-like brick wall. I felt a surge of motivation going through it since it meant the race was almost over, but that feeling didn’t last long.

The final miles were incredibly challenging. The background started to fade and I was really only cognizant of two things: the desire to keep moving, and the pain that was slowly overwhelming me. Fortunately, I was able to hold the pace between 6:47 and 6:52 for miles 20-26.

I crossed the finish line 29 seconds ahead of schedule, finishing with a time of 2:56:31.

The finish line of the California International Marathon
The finish line of the California International Marathon


For the full training details, feel free to check out my Strava training log between May and December. I generally ran 5 times a week, between 20 and 50 miles each week, about 820 miles in total.

Miles per week



I trained at four different paces. What I’ve listed below are the paces I was able to train at during the second half of the cycle, after the Urban Cow Half Marathon. During the first 9 weeks, I was still building a considerable amount of fitness, and each was 30s-1m slower per mile.

  • Easy: 8:30 min/mile
  • Steady-state: 7:30 min/mile
  • Marathon Pace (MP): 6:50 min/mile. The goal pace for the marathon.
  • Lactate Threshold (LT): 6:30 min/mile. This is roughly defined as the fastest pace you can hold for an hour.


  • Monday: Off
  • Tuesday: Workout. I’d typically end up running 6-10 miles on these days in total, but in a workout style. E.g. 6-mile repeats at lactate threshold pace with 2 minutes rest in between.
  • Wednesday: Easy, about 5 miles.
  • Thursday: Steady-state. About 1m to 1.5m slower than goal marathon pace, 6-12 miles.
  • Friday: Off
  • Saturday: Long run. These were between 14 and 20 miles, occasionally with marathon pace or lactate threshold pace miles worked in. An example 20-mile workout could consist of a 10 miles steady-state, 4 miles at MP, 1 mile easy, 4 more miles at MP, and a 1 mile cool down.
  • Sunday: Medium-distance easy run. Typically between 5 and 10 miles.

Race day nutrition

On the way to the race, about an hour and a half before the start, I had a bagel with peanut butter and a banana. I carried four GU Energy Gel packs, two with no caffeine and two lightly caffeinated. I took one at the start line, another around 10 miles in, 15 miles in, and a final one at 21 miles. I drank a few sips of Nuun at roughly four water stations.

The next marathon

I’ve signed up for the Berlin Marathon in September, and have my sights set on a 2:45. I plan to keep the same general training approach, but want to do a couple of things differently:

  • Increase the peak weekly mileage to about 70 miles/week. I felt like 50 miles/week was the bare minimum for a sub-3 marathon. Increasing the mileage a bit should help, especially during the end of the race.
  • Add in strength training. I used to lift weights, but dropped it almost entirely to make room for running. I think there’s a lot of value in continuing to do leg-strengthening exercises.
  • Focus more on speed during the workouts. Coming from heart-rate training, I felt uncomfortable during the faster workouts. This time around, I’ll try to work in plenty of miles at a sub-6 pace.