Most people train the same way every week of the year. A bit of easy, a bit of hard, a long one on the weekend, repeat. Then they wonder why nothing much changes after the first few months.
The problem is not effort. It is asking your body to build several different things at once, and it cannot. So it builds none of them properly. Training blocks are how I get around that.
I train people in blocks instead. A block is a stretch of weeks with one clear job. You do that job long enough for the body to actually change, then you move to the next one and keep what you built.
This is the detail behind the structure I mention in what your aerobic system actually does.
What a cycle of training blocks looks like
Three blocks, in this order. The order is the whole point.
The aerobic block: 8 to 10 weeks
Mostly easy work. The job here is plumbing. Capillaries, the ability to burn fat as fuel, and the capacity to train often without falling apart.
This is the long one, and people hate that. Eight to ten weeks of mostly easy running feels like nothing is happening. It is the block that changes people the most and it is the block they most want to skip.
Why it takes that long: the changes you are after are structural. You are growing blood vessels and building engines inside muscle cells. That is not a two week job. If you stop at four weeks because you got bored, you stopped before the thing you were paying for showed up.
Newer runners often need longer than ten weeks, and I will happily run twelve or more. Someone with years of training behind them might be fine with eight.
The anaerobic block: 2 to 4 weeks
Now we add the harder work, on top of a base that can absorb it.
This block is short on purpose. Hard work is a strong signal and the body responds to it quickly. It is also expensive. Run it too long and you stop adapting and start digging a hole.
Two to four weeks is enough to get the benefit and get out. If someone is newer, or has had injuries, I stay at the short end. If the event demands more, or they have handled it before, I go longer.
The key thing is that this block is built on the previous one. Hard training on a proper aerobic base gets absorbed. Hard training on nothing just accumulates damage, which is what most people are unknowingly doing all year.
The deload: 1 to 3 weeks
Volume comes down. Intensity stays honest, so you are not sitting on the couch, but the load drops off.
This is the block people skip and it is the one where the adaptation actually lands. You do not get fitter during training. You get fitter recovering from it. The deload is where the last few months turn into fitness.
How long depends on how hard the cycle was and what is coming next. One week after a moderate block. Two or three after a heavy one, or if life has been chaotic, or if we are heading into an event.
If you finish a deload and feel restless and keen, that is the right feeling. If you finish it still tired, it was not long enough.
Why the order matters
- Aerobic first, always. The base is what lets you handle everything that comes after. Build it last and you never really build it.
- Anaerobic second, and briefly. It is the accelerant. It works fast, and it works best on top of something solid.
- Deload last, without fail. The block that banks the work. Skipping it means the previous three months only partly counted.
Run this on a loop and each cycle starts from a higher floor than the one before. That is what progress actually looks like over a couple of years, rather than the sawtooth of getting fit, breaking down, starting again.
How this fits an event
Count backwards from the date. A cycle of 11 to 17 weeks lands neatly in front of most events, which is why I talk about needing roughly twelve weeks to prepare properly for something.
For a trail race like Whale Rock in late February, that means the aerobic block starts around late November. Leave your run at it until January and you are trying to do the plumbing and the hard work at the same time, which is the thing this whole structure is designed to avoid.
What it is not
It is a sequence, not a timetable. If work explodes in week five of your aerobic block, the block stretches. If you get sick in the anaerobic block, we go back rather than push on.
And the ranges above are starting shapes, not rules. I set them per person off an assessment, because a 52 year old returning after fifteen years off and a 30 year old who ran at school need different numbers even if they have entered the same race.
If you want this structured around your event and your life rather than a template, that is exactly what coaching with MFHP Adventures does.