How I Turned My 5k Pace Into My Half Marathon Pace In 6 Months..By Only Running 1-2 Days Per Week

6 months ago, I ran a 5k in 20:35 (6:37 pace).

3 days ago, I ran a Half Marathon in 1:26:19 (6:35 pace).

That's over 4x the distance at a faster pace!

The craziest part?

I did it only running 1-2 days/week!

This blog post will explain how I did it.

Here is my weekly running frequency over the past 6 months:

November: 1-2 days (Z2)

December: 2 days (Z2)

January: 0-1 days (Z2)

February: 1 day (intervals)

March: 1 day (Intervals)

April: 0-1 day (Z2)

May: 2 days (1 Z2 + 1 hard)

June: 2 days (1 Z2 + 1 hard)

 Mileage: 5-18/wk.

I didn't consistently run twice a week until late April, and I never ran more than 18 miles in a week.

Obviously, this isn't enough running to explain how I improved so much and so quickly.

Here's the secret:

Zone 1 stationary biking. 

95% of my cross-training was stationary biking and it was all done in Zone 1.

If you've never done Zone 1 training, you won't believe how easy it is.

I'm talking so easy that you feel like it can't possibly be providing any benefit.

But it is.

Oh, it is.

The main reason why I love Zone 1 biking so much is this:

It allows me to improve my endurance while taking virtually nothing away from the rest of my training.

I strongly recommend it to anyone with a history of running injuries, new runners, and/or anyone who loves to lift.

I was first exposed to the benefits of Zone 1 training byAlan Couzens.

He argues that Zone 1 provides most of the benefits of Zone 2 but with far less stress on the body.

As someone who loves to lift, this was music to my ears, but it seemed too good to be true. 

Here is what my Z1 bike training has looked like over the past 6 months:

• November-January: None
• February: 3-4x30-60 mins
• March: 2-3x45-60 mins + 1x90 mins
• April: 2-3x45-60 mins + 1x90 mins
• May: 2x45-60 mins + 1x60+ mins
• June: 2x45-60 mins + 1x60+ mins

All rides were done at 115bpm.

I had tried Zone 2 in the past but always had issues with it fatiguing me too much for lifting. And honestly, it was too long and too hard for me to consistently do.

So, I decided to give Zone 1 training a try during my last cut.

I figured, at worst, it would do nothing for my aerobic endurance, but at least it would burn extra calories.

And at best, it would burn extra calories AND improve my fitness 

Well, it did both.

From Feb-March, while only running once per week, I improved my 5k time from 20:35 to 18:46.

I also biked 45-90 mins 3-4x/week at ~115bpm.

I realized I was on to something.

This low-intensity biking allowed me to improve my endurance while still lifting heavy 4 days per week and more importantly, it allowed me to run consistently.

I figured if it worked that well for the 5k, I might as well keep it going and see if it would work for a half marathon.

But a Half Marathon is much different than a 5k, and I knew running once a week wouldn’t cut it.

I thought even twice a week might not be enough to sufficiently improve my muscular endurance.

 But I knew my body wouldn’t be able to handle 3 days per week, so I ran twice a week for the past 8 weeks.

And that’s the first time I’ve been able to do that in over 20 years.

My basic plan was this:

• 1 long run
• One high intensity run

The long run ranged from 60-90 minutes (6-12 miles), and the high-intensity runs ranged from 4-8 miles.

The first 5 weeks, my long runs were all done at <140bpm, firmly in Zone 1/2.

The last 3 weeks I turned these into progression runs, I would run the first 60-70% in Zone 2 and the last bit at race pace or faster.

Here are some  examples of my high intensity days:

• 2x2 miles at HMP
• 4x2k at 10k pace
• 7x800m
• 3x2 miles at HMP
• 5 miles at HMP
• 8 mile at HMP

 Again, over the past 6 months, I only had ONE high-intensity running day per week. 

The rest was done in Zone 2 or slower.

Summary of past 8 weeks:

• 3 hours per week of Z1 biking
• 1-1.5 hours per week of Z1/Z2 running
• 30-60 minutes per week of Z4/Z5 running
• 4-6 hours per week of lifting

 The point of this post is this:

 Cross-training can be powerful.

 It's a great way to improve your aerobic endurance if:

• you have a long history of getting injured from running
• you are new to running
• you want to be able to run and lift heavy
• you are overweight

For the past 15 years I thought Z1/Z2 was a waste of time.

 Trust me, it's not.

Please don't be like me.

 Just try it.

I promise you won't regret it.

And you may even grow to like it.