Threshold Runs

A few years ago, I got done with a weekend group run and we were grabbing coffee at a shop in Coronado. We were chatting it up and I vaguely remember the workout we did had some “tempo” in it; however, I vividly remember Brielle saying “Chase if you had a kid you’d name it Threshold!” A bit exaggerated, but I think that loosely captures how I feel about threshold runs. In my opinion, most recreational runners could benefit significantly from threshold runs. So whether you’re gearing up for Rock and Roll Half/Full marathon or a Hyrox, you might want to consider adding some threshold runs into your programming.

What is a threshold run?

Let’s get the technical stuff out of the way. You don't need to memorize the science, but a quick overview helps. Your body has two key aerobic thresholds:

A threshold run targets that LT2 zone. The goal is to spend time right at or just under the edge of what's sustainable or said differently “comfortably hard.”

Why does this matter for a half marathon?

Your half marathon pace almost certainly lives near your lactate threshold. If you never train there, race day feels harder than it should. You're asking your body to sustain a pace it hasn't learned to handle.

Threshold work teaches your body to clear lactate more efficiently. Over time, your LT2 shifts, which means you can run longer before you feel like you “have to slow down.” This is often the difference between a race (or even a workout) feeling strong or struggling to finish.

I don’t coach any Hyrox athletes but from the ones who I run with - I’d argue increasing the length of time you can spend close to LT2 increases your overall aerobic engine which ultimately gives you a much better handle on the event.

How to find it?

I like to use rate of perceived effort (RPE) to gauge threshold effort which is generally around a 7/10, though that can shift depending on where you are in your training block. It’s definitely not easy but you are in control for the entire duration of the session. I find that most people (sometimes myself included) run these too hard because they feel good and end the session pushing into 10k pace range. Good rule of thumb is “less is more” as that prepares you for the next threshold run which should be longer.

The most accurate predictor of your threshold is a metabolic test. This involves a run at progressively faster speeds with blood samples (just a prick) in between intervals. My friend Rory Sutherland offers this as a service if you’re local to San Diego.

If you can’t get in for testing or are not a fan of needles (most people will fall into this bucket) - I just say shoot for “ comfortably hard.” It should feel like you're working, but not like you are racing. If you're gasping after 4-5 mins, you've gone too fast in the range. If you end the session saying “I could do that for several more miles” you didn’t go fast enough in the range.

Types of threshold runs

Broken
These are generally set up with a total time at intensity as a guideline and involve rest breaks in between. They allow you to accumulate meaningful time at effort without the mental and physical cost of a continuous run.

Sample workout
- 4 × 5 mins at threshold with 2 min jog recovery
- 5 × 1 mile at threshold with 3 min jog recovery

Straight
These generally have no breaks in between and target sustained efforts at threshold effort. I recommend these after you have built confidence physically and mentally with broken efforts.

Sample workout
- 25 mins at threshold
- 3-5 miles at threshold (depending on experience).

Coaching tip: Don't let the early reps fool you into going too hard. The first rep or first 5-7 mins should feel almost too easy; deep in the session or final reps are where the secret sauce is made.

Athlete Spotlight

Shout out to my Chase Distance teammates who took on two events on opposite sides of the country: Mountains 2 Beach half marathon/marathon and Boston! Joe and Payton completed the half at M2B, myself Alex and Andrew took on the full. Sabrina and Beth both flew across the coast for their first Boston marathon. As a coach it brings me a lot of joy to see my people succeed. Also, training and running with this group was really one of the more rewarding journeys I’ve been on thus far in this 16-year running stint.

That’s it for this issue. Let me know how your next threshold run goes! As we established earlier - it’s one of my favorite topics!