Steady-State Running: Why Zone 3 Training Matters
Steady-state running is neglected by many runners. All too often, we pursue aggressive mileage goals of easy running early in the training cycle and then top it off with demanding lactate threshold runs, VO2max intervals, or race-specific workouts closer to race day. But moderate runs trigger potent adaptations to increase your aerobic engine. In this article, you will learn how to pace these workouts and where to place them in your schedule.
“Workouts at the aerobic threshold are neglected by many runners.”
Steady-State Running in Theory
Steady-state running equals training in zone 3. Hence, it is between zone 2 training (easy runs) and zone 4 training (lactate threshold runs). For most runners, zone 3 training is slower than half-marathon pace but faster than marathon pace. In scientific terms, the maximal steady state (MLSS) is the highest workload you can maintain without continual lactate accumulation. That is approximately your current estimated 2-hour race pace intensity.
For that reason, they are also often referred to as high-end aerobic runs. If you monitor your runs by heart rate, steady-state runs are 10 – 20 bpm higher than your easy runs, but about 15 bpm lower than lactate threshold runs. The distinction between the aerobic threshold (LT1) and the lactate threshold (LT2) is that from LT2 upwards your body can’t clear lactate from your system as fast as it is produced as a by-product of your anaerobic metabolism.
When we look at muscle-fiber recruitment, steady-state runs do not strain fast-twitch fibers. For that, intensities at 10K race pace and faster are necessary. But they do recruit significantly more slow-twitch fibers (ST-fibers) simultaneously than easy runs. This increased demand for ST-fibers triggers useful adaptations, such as more and larger mitochondria, increased capillarization, and elevated aerobic enzyme levels.
It is important to note that these adaptations are useful for runners of all the classic road race distances. For half-marathon and marathon runners, the benefit is evident as the aerobic threshold intensity is near race-specific pace for those events. For 5K and 10K runners, replacing some zone 2 runs with zone 3 runs help build your aerobic engine. That said, don’t go overboard either as steady-state runs require more recovery time than easy runs.
Zone 3 Training in Practice
Precede steady-state runs by a 5 – 10 minute long warm-up jog as well as a brief cool-down. There’s also the option to start and end each steady-state run with a segment of easy running. The main set of zone 3 running is typically in the range of 30 to 60 minutes, but not longer than 75 minutes. Otherwise, you risk sabotaging future workouts due to excessive fatigue. Find a middle-ground that works for you.
There is also the option to run alternations, switching between easy pace and steady-pace every mile (or every 2km). That way, you get in running mileage without accumulating too much fatigue. Progression runs are also popular with some runners. Here, you would start at an easy pace and then run the final half or third at a steady pace. Equally, you can attach some zone 3 training at the end of your long runs occasionally.
Another important factor is the placement of your long runs in your training cycle. It is useful to emphasize steady-state runs during base training as it is a pre-requisite for lactate threshold training. But in the final weeks of a training program, it has to make way for more race-specific training. For 5K and 10K runners, that emphasize VO2max. For half-marathon and marathon runners the priority becomes race-pace training.
Be mindful that steady-state runs can dig into your glycogen stores. Zone 3 intensity requires 80% glycogen and only 20% fat. A post-workout snack consisting of 50g carbohydrates (high glycemic index) and 10 – 20g of easily digestible protein ensure a quick recovery. If you still tend to bonk during workouts, ingest some fruit 30min before your run to ensure even blood sugar levels or carry an energy gel.
In summary: Steady-state running is an integral part of your training. It bridges the gap between easy runs and runs at or above the lactate threshold. Although more demanding than easy runs, they are still relatively easy to recover from. You can place them before or after hard workouts if their duration isn’t excessive. Experiment with one steady-state run per week initially and add a segment to your long runs on occasion.
Sandro Sket, CSCS