One of the most common errors athletes make in training is defaulting to an effort level that resides somewhere between the aerobic and anaerobic, or lactate thresholds. In essence, not hard enough to get maximal training benefits, but too hard for recovery. Let’s call this place Mediocrityville because, if you spend too much time there, you will likely see very mediocre results. Effort management is fairly simple when you know what the two primary thresholds are and how to use them effectively in training.
Your aerobic threshold, in simplest terms, is the point where your body transitions from burning primarily fat to burning primarily carbohydrate (glycogen). To be clear, glycogen is always being burned even at very low intensities, it’s the percentage relative to fat that matters. As intensity increases, your body needs to utilize faster fuel sources so it taps into your glycogen stores. In tests where blood lactate is measured, the aerobic threshold is often indicated when levels reach 2mmol/litre.
The second threshold is referred to in different ways and can be measured through a variety of methods. Your anaerobic, or lactate threshold, is the point where you begin to recruit anaerobic pathways to maintain the workload (anaerobic meaning without oxygen). In simplest terms, this is the point at which you start to feel out of breath. If you were involved in a test where they determined your lactate threshold, they would have measured the amount of lactic acid in your system. As you work harder, you accumulate more lactic acid in the bloodstream. Your lactate threshold is the point where your body starts to produce more lactic acid than it can get rid of. Both anaerobic threshold and lactate threshold are usually used to describe the same thing because they often occur at very similar intensities, but, technically speaking, they are different.
To get the most benefits from your training you need to spend time in and around these threshold efforts. You will stress your body and promote adaptation. You can also improve by doing shorter, faster intervals that will push you beyond your second threshold.
When you end up floating around in between these two thresholds, though, you have arrived at Mediocrityville.
It’s easy to end up doing lots of training at this level because you feel like you’re working hard, but not so hard that you risk throwing up. Workouts that you’re supposed to do above your anaerobic threshold are hard. It’s easy to slip down to Mediocrityville when the work starts to get tough.
You might be the toughest person on the planet, but if you are trying to do intervals that are too long at too high an intensity, you won’t be able to sustain the effort and you’ll end up in that mid-zone again. Similarly, rest intervals that do not allow appropriate recovery between hard sets can limit your ability to hit higher intensities.
The opposite occurs when you start pushing too hard when you’re supposed to be working aerobically. There are benefits to be had when you’re going easier: the utilization of fat as a fuel source and the corresponding decreased need for glycogen, which you store considerably less of than fat. Sometimes you’re supposed to be doing an easier workout because the goal is for active recovery. This often happens during group sessions when the parameters and goals aren’t clearly laid out and people start to push the pace.
Most good training programs are designed to maximize the benefits and adaptations that happen around the two thresholds I’ve talked about here. The space between is not always bad, it’s just that too often athletes end up there without realizing it and don’t reap the benefits of their workout time. Manage your effort accordingly and good things will happen.
Ironman champion Jasper Blake is a coach from Victoria.