Are you putting in the long slow easy runs, track workouts, yet struggling in the marathon? If you are, you are missing out on a crucial piece. Zone 3 running. The “efficiency run” or “tempo run.” 

While zone 2 has been receiving all the hype lately, the importance of zone 3 has not been getting enough attention. People call it the ‘grey zone’ and poo poo it. This is for a few reasons, mostly from being used inappropriately. Many runners run too hard too much vs keeping an easy or recovery run exactly what it is supposed to. So instead of using that recovery run, they get into a race mindset and enter zone 3 too often. And then are too fatigued to properly push threshold or V02 max training. So pretty much all runs end up being between easy and threshold, or the ‘grey zone’ and are not achieving desired benefits. Another reason: newer runners do not have the base aerobic system nor the strength in the tendons and soft tissues, which can result in poor results and injury. 

But used appropriately, Zone 3 being “unimportant” is a myth. In fact, that is why elite runners train a lot of volume in Zone 3. It is why I accomplished my marathon goal, and ran to my best, a goal greater than any run pace chart said I could do, despite messing up my nutrition and taking in zero until 30km in. It is why marathon runners (and other road racers) I trained and followed zone 3 training appropriately, achieved their goals, often surpassing expectations. It is also why those who did not follow zone 3 properly and ran all their runs way too easy like a Sunday stroll, or raced every session, did not achieve their goals. Zone 3 is crucial for the road runner, especially for anyone trying to break a 4hr mark in the marathon.  It requires patience and discipline, exactly what you need to achieve your best.

Here are some reasons why “Efficiency Run” is so important in helping you achieve your marathon goal.

1. You practice close to marathon pace. Pace training is crucial for many events, especially the marathon. This prepares your body for the mechanical stress it will undergo. It also trains your body to utilize similar energy as you will on race day, and trains both your body and brain’s ability to maintain a moderately hard effort for long periods of time – just like the demands of the marathon or other races. There is a reason that Kenyan elite marathoners are known for building a large majority of their runs into zone 3 (also called tempo or efficiency pace). If you run all of your runs too easy, come race day, you will not be physically nor mentally prepared. Conversely, if you run all your runs too hard and do not practice patience and discipline, you wil not be physically nor mentally prepared, more likely injured and / or burnt out. They say practice makes perfect. I prefer ‘perfect practice makes perfect.’ 
2. Efficiency running. While V02 max gets the sexy rave, we all have a ceiling limit. How do you get better? Becoming more efficient. And over time, this translates to getting faster not only at your goal race pace, but with your easier and harder runs. Rather than slogging along and making all runs too easy, or running too hard and ‘tight,’ you are training your body to be more efficient at your desired pace. 

3. You are also better adapted to lactate clearing without the higher stresses of threshold training. Zone 3 sits just below threshold, so the body improves at processing and clearing lactate more efficiently. This is key especially for the marathon or half marathon, as you can sustain a faster speed without fatigue accumulation as quickly!

Are you intrigued? So What is Zone 3? 

Zone 3 is, essentially, the higher aerobic zone. I call if a ‘feel good’ pace or efficiency run, running strong but manageable. A HR of 70-80% max or with an RPE scale, think of 6-7/10. It is where conversational pace becomes more difficult, but you could still talk in broken sentences. It is the pace that aligns with marathon effort (to half marathon depending on your fitness level) for majority of runners.

I personally think of this as ‘feel good’ pace – not into threshold yet not running too easy. For example, when I was a competitive triathlete, a weekly standard run was between 60 and 75min, warming into the first couple of miles into zone 3. If my HR was creeping at the upper end, I reduced it. I loved this run!  Once warmed up, it was fun. I felt fast but relaxed. And not destroyed afterwards. Over weeks, I noticed my times getting faster at the same HR at both this zone and the zones above and below it.  It is a great tester run without needing to recover and race or need a large amount of recovery time afterwards. Done consistently, you will also see paces at easier runs (zone 2) and higher threshold work get faster as well. 

A couple of Zone 3 session examples:

• Steady-state effort for 30-45min (after 10-15min warmup). The pace will feel easy earlier on, but slowly gets tougher, providing a useful stimulus for longer races.

• Cruise tempos of 3-4 x 10-15min with 2-3min breaks between. This is a great introduction to tempo running, as a different stimulus or break from steady state sessions, and to develop some race-specific endurance, without excessive fatigue buildup with the more intensive intervals training. It also forces you to practice patience and the discipline of running what you are capable of, vs treating this as hard efforts. Over the repetitions, you will notice the pace becoming more difficult. If not, I always tell my athletes they can go a bit faster on the last one and make a note of that. Remember to start more conservatively and ideally, even or negative split!

To summarize, Zone 3 training is highly beneficial because it enhances run economy, aerobic efficiency and the ability to clear lactate, and the ability to hold a steady pace for longer durations that replicates race-day pacing and intensity. Used appropriately, a powerful tool in the runner’s box!

Tammy Kovaluk, Msc

Strength and Conditioning, Run coach

Side not: if you want to learn more on zone training, a recommended podcast to learn more on run training zones is with Alyssa Olenick, PHD on Strength Running Podcast.