How to schedule yoga around endurance and strength

Three parts of you set how far you can reach: your nerves, your muscles and your tendons. Each changes at its own speed.

The nerves give way first. After one session of holding a shape, you can reach further, but most of that extra reach is not new length. The point where it starts to hurt comes later. You can go further before you stop.

The muscle takes weeks. In one study, men trained their hamstrings, the muscles at the back of the thigh, for six weeks with lowering work, where the muscle pulls while it lengthens. The bundles of fibres inside the muscle grew longer. Four weeks after they stopped, the bundles were back where they started.

The tendon does not get longer. Researchers dated 28 Achilles tendons using a trace of carbon left in the air by nuclear bomb tests. The core of each tendon still carried carbon from its owner's first 17 years of life. Pooled studies of people who held long shapes for weeks found the muscle a little less stiff, and the tendon unchanged. So yoga can give you more range at the ankle without softening your Achilles. The tendon stays as springy as ever when you run.

So the range you gain sits in the parts that change fast, and they change back fast. Researchers pooled studies of 556 people who built range and then stopped for two to six weeks. Their range slipped back, though not all the way. The people who stayed active through the break kept theirs.

In another trial, 32 adults built range in their hamstrings over four weeks. Then some stopped, and the others kept going two or three days a week. Those who stopped lost some of it. Those who kept going lost none.

Hard training does not keep range for you. In 31 rugby players over eight weeks of a season, those who added yoga twice a week kept their hamstring range. The others lost 14.8 percent of theirs.

What counts is how often you come back. Researchers had 24 men hold their calf muscles long, with the ankle bent up, for six weeks. One group did it for six minutes, once a week. The other did two minutes, three times a week. The weekly total was the same. The men who came back three times a week could bend their ankles further, and their calves were less stiff. Once a week changed nothing.

A review of 23 studies found the same. Range rose more the more days a week people practised. How long each single session lasted made no difference. So tie the flows to your sessions. Then you come back to your range on most days of the week, without finding extra time for it.

Sitting still stiffens muscle within minutes. After the drive to the lake or the trailhead, the relaxed muscles around your hips and shoulders resist small movements more than they did while you were moving. Move them, and within moments much of that stiffness is gone. The effect is called thixotropy, and it comes from movement, not heat.

The stiffness returns once you stop. Footballers whose thigh muscles cooled while they sat through half-time sprinted 2.4 percent slower when play restarted. Players who kept moving lightly did not slow at all. So do the flow straight before the session, not an hour before, and keep it moving. Then start the session slowly.

A long hold works differently. Researchers held people's hamstrings at a fixed length for 90 seconds. The resistance fell by about a third, while the muscle stayed fully relaxed. It fell the same way in people with a spinal cord injury, whose muscles cannot tighten at all. The give came from the tissue itself. So hold a shape with the muscle relaxed, not working.

A long hold also leaves the muscle slack for a while after you stand up. The hold turns down the signals from your spinal cord to the muscle. A swing or a hard stride needs the opposite, a full burst of signals at once. So save the holds for when no fast work is coming soon. A base session afterwards is fine, but a set of swings or sprints is not.

Front crawl takes your arm overhead thousands of times a week, and your upper back turns with every breath. That is why the flow on the jetty works the shoulder blades and upper back.

Before a run, open the hips. With every stride your back leg swings out behind you, and that only works if the front of the hip opens. Hours in chairs and car seats leave the hips still and bent. So move through deep lunges and warrior shapes, forwards and out to the side, without holding any of them.

A ride keeps your back rounded and your hips bent for hours, and they never straighten. So after a ride, give your back and hips movement in every direction, not one more shape to sit in.

A short run at base, the steady effort you could keep up for hours, moves your hips and legs through their range and costs little. A long run, or a run at threshold, VO₂max or sprint, swings your legs through the same arc for hours or at full effort. You never turn, reach overhead or squat deep. So afterwards, hold the back and the front of your legs long, in a downward dog or a deep lunge.

After the bells, hold too. A kettlebell session is either power, fast work like the swing, or structure, slow heavy work like squats and carries. Both keep your trunk braced and your spine still. So afterwards, hold a twist or a deep hip shape long enough for the tissue to give. Let your feet, hips and shoulders work together in it, because no joint works alone.

A range session goes deeper than any flow. It holds more shapes, for longer, and then you work in each shape at its new length. Like any long hold, it leaves the muscle slack. So on a day with both the bells and an endurance session, put range after them, or give it a day of its own. Never put it right before power, threshold, VO₂max or sprints.

Balance is a skill of quick catches, and tiredness slows the learning of a skill for days. In one study, adults learned to control how hard one hand pressed. Those who tired the hand first learned at about a quarter of the rate. The next day they were rested, and still behind. They caught up only on the third or fourth day.

So give balance a fresh day. Keep it off the day of a threshold, VO₂max or long session, and off the morning after one, just as power belongs on a fresh day. If you train with the bells that day, do them first. They need you at your quickest, and a few fast sets leave you only a little tired.

The first time a muscle works at a new, long length, it tears a little. Do the same work again, and the muscle is protected. In 35 men who repeated a bout of hard lowering work with their arms, most of the protection from the first bout lasted at least six months. So in the week before a race, do only shapes you have practised for weeks. A session of new, deep shapes two days out could leave your legs sore on race morning.

After the race, your muscles are damaged, so keep the yoga gentle. In one trial, 30 men damaged the muscles at the front of their thighs with hard lowering work. Over the next three days, some held thigh and hip shapes hard, some gently, and some did nothing. The hard holds left them weaker the next day and raised a blood marker of muscle damage. The gentle ones eased the soreness and helped their strength come back a little. So move gently through shapes you know, and hold nothing hard.

Your range sits in your nerves and muscles, not in your tendons. That is why it comes within weeks, and why it goes again within weeks when you stop. One long session a week does little to hold it. A few minutes on most days does.

So put a few minutes of yoga beside most of your sessions. Keep moving before you start. Hold the shapes once the day's fast work is done.