Why training at one effort doesn't cut it

You head out the door for a run, a ride or a swim. You go at the pace that feels right today. Not easy, not hard. A good solid effort, the same as last time.

It feels like training. But ask what it was for, and there is no answer. You went out and hoped it would work.

01

Two riders with the same engine.

In Texas in 1988, researchers tested 14 competitive cyclists. All of them had almost the same VO₂max, the most oxygen the body can use. On paper, they were equal.

Then each one rode as long as he could at the same hard effort. Seven of them lasted about an hour. The other seven gave up in about half that.

What split them was not the size of the engine. It was how hard each could ride before his legs began to flood with lactate, and how many tiny blood vessels fed his thigh muscles. Those two things explained more than nine tenths of the difference.

02

Endurance runs on four systems.

Endurance is not one thing. It is a few systems working together, and each one can be strong or weak on its own.

The first is the base. It is your aerobic system: your heart, your blood vessels and the tiny power plants inside your muscles, called mitochondria. Together they carry oxygen to the muscle and turn it into movement.

The second is your threshold. It is the hardest effort you can hold steady before lactate builds up faster than your body clears it. Above it, sooner or later you have to ease off.

The third is your VO₂max, the ceiling. It is the most oxygen your heart can pump and your muscles can use, all at once.

The fourth is your nerves. Speed starts as a signal from your brain to your muscles. The stronger and faster that signal, the more muscle fires at once.

03

Each effort trains one system most.

So there are four efforts, one for each system. A base effort you could keep up for hours. A threshold effort you could hold for about twenty minutes, and not much more. A VO₂max effort lasts a few minutes. A sprint is all out, and it is over when you start to slow.

Each is the same in the water, on the bike and on foot. The sport changes, but your heart, lungs and muscles work the same way.

04

Your muscles build what the session strained.

How does a ride turn into fitness? One team of researchers followed it into the muscle. Healthy volunteers did seven hard sessions on a bike. After the first, third, fifth and seventh, the team took a tiny sample of thigh muscle, four hours after the session and again a day later.

Inside each muscle cell, building anything starts with a message, a copy of the instructions for one protein. One protein, PGC-1α, tells a muscle to build new mitochondria. Four hours after the very first session, the message for it had risen more than tenfold. A day later it was back to normal. The same thing happened after every session. A burst, then quiet.

The protein itself did not fall back. It rose after the first session and stayed up. By the third session, the muscle already had more of the machinery that burns fuel with oxygen. Each burst left a little behind, and the little pieces added up.

So fitness is built one session at a time. Each session sends a short signal, and your muscles build more of what that session strained. A long base hour, a hard twenty minutes, a few minutes at the top and a few seconds all out strain different parts of you. So each one builds something different.

05

Base work builds the roads.

The base is roads and power plants. Blood vessels that carry oxygen into the muscle, and mitochondria that use it. They grow slowly, from hours, and base is the only effort you can repeat for hours, day after day.

In Spain, 12 runners trained for five months. Both groups did the same amount of hard training. One group spent more of its other time at base. The other spent more of it in between, a bit harder than base.

Both groups got faster over a 10.4 kilometre cross-country race. The group that kept to base improved more, by about two and a half minutes against two.

06

Threshold raises what you can hold.

Think back to the cyclists in Texas. Their engines were the same size. The ones who lasted twice as long could ride harder before lactate began to pile up.

That is what threshold work trains. It moves the line up, so a steady effort that once flooded your legs becomes one you can hold. On a long climb, in a headwind or on a swim against the chop, it is the effort you live at.

07

Hard intervals raise the ceiling.

In Norway, 40 moderately trained men trained for eight weeks. One group ran long and slow. One ran at threshold. Two groups ran hard intervals. Every group did the same total amount of work.

Only the interval groups raised their VO₂max. It went up by 5.5 and 7.2 percent, and the amount of blood their hearts pushed out with each beat rose by about a tenth. The long, slow and threshold groups did not raise it.

The same amount of work, done harder, raised the ceiling.

08

Sprints train the nerves.

In Utah, ten trained cyclists added short, all-out sprints to their normal riding for four weeks. Across the whole month, the sprints added up to 28 minutes.

Afterwards, the electrical signal in their main thigh muscle was stronger. More of the muscle was being switched on at once.

A sprint is the whole body at full effort. It is power, in a run, a ride or a swim. Long, steady sessions never use it, so you slowly lose it.

09

The effort in between builds neither.

The four systems are not sealed boxes. Every effort trains a little of everything, which is why both groups of Spanish runners got faster.

But each effort trains one system far more than the others. And the effort in between, a bit harder than base and a bit easier than threshold, does neither job well. It is too hard to repeat for hours, so it builds fewer roads. It is too easy to push the line, so the line stays where it was. It costs you, and it sends a weak signal.

That is the good solid effort from the start of this chapter. Done every day, it builds a little of everything and not enough of anything. The Spanish runners who spent more of their time there improved less.

Endurance is built part by part, whether you run, ride or swim, the same way as power, structure, balance and range. Give each session one of the four jobs, and you build that part on purpose.

Sources

Book

Workouts