March

Happiness

At the end of a workout, your body suddenly feels relief after all that stress. And that relief feels like happiness.

I get a similar feeling in the mountains. As I climb higher, everything becomes harder. There's less and less oxygen, and my body seems to panic as it struggles to cope. Coming down reverses the process. More oxygen, more relief: a kind of altitude euphoria.

Something similar happens after a workout. During hard exercise, your muscles burn through oxygen, your lungs work flat out to supply it, and your liver scrambles to clear lactic acid from the blood. Then, suddenly, it's over. Your heart rate settles, your muscles relax, and there's enough oxygen again. Euphoria. An oxygen-drunk kind of bliss. Endorphins enter the bloodstream, and your brain registers happiness. Never mind endorphins: studies suggest that exercise also releases endocannabinoids, substances your body produces to activate its own cannabinoid receptors. Yes, you read that right.

Runners get this regularly. You soon get used to it and start looking forward to your next dose of post-run happiness. Perhaps that's what keeps many recreational runners coming back. I won't pretend it doesn't matter to me. I get that happiness every day. No therapist required. Just running shoes.

Matters of the heart

Your heart never gets a day off. Twenty-four hours a day, decade after decade, it keeps going. We admire biceps and a well-shaped backside, but the muscle keeping us alive gets much less attention. We know it matters. We still take it for granted.

Running gives that muscle a workout. As with other muscles, I don't want to overwhelm it with too much work too soon. The idea is to build gradually, steadily, and consistently. I picture the result as an internal bodybuilder: strong and tireless.

The heart and blood vessels get the biggest health boost from running, with the greatest benefits coming from low-intensity training.

Some marathon and half-marathon organizers require an ECG and medical clearance before you race. That makes sense: they're trying to keep unprepared runners from taking on more than they can handle. So don't give the organizers a hard time over the paperwork.

I wanted a strong heart as well as a stronger body. I wouldn't see every improvement in the mirror. That didn't make it any less worthwhile.

Lions and aerobic running

Male and female lions live somewhat different lives.

A male has a mane and a heavy body, which make heat harder to tolerate. Much of his time is spent resting in the shade or moving at a stately pace. He's incredibly strong, but saves that strength for when he needs it: fighting rivals or helping bring down prey. He can run very fast, but not for very long. I think of him as a sprinter.

Lionesses are more active. Lighter and without manes, they cope more easily with the heat. They do much of the hunting and also care for their cubs. They spend more time moving and can keep at it for longer.

To me, this is a good way to picture the difference between aerobic and anaerobic running.

Aerobic means involving oxygen. At an aerobic effort, the body can supply and use oxygen to produce most of the energy needed for movement. The first explanations I read put much of this running somewhere around 120 to 160 beats per minute, although the actual boundaries depend on the runner.

For me, aerobic training meant a slightly elevated heart rate and an easy pace. It built general fitness and endurance. I could keep going for a long time, even if I wasn't moving particularly fast.

I thought of it as putting something aside for future fast runs. Kilometer by kilometer, I was building aerobic capacity and a reserve of endurance. Lioness running. Easy to remember.

Anaerobic running

A short burst of energy at top speed draws on anaerobic energy production: energy supplied without oxygen. Of course, you keep breathing, but the oxygen coming in can't cover the effort. For a while, your muscles draw on their stored reserves. You're spending that energy here and now, but you'll have to pay it back later. Spend now, recover later: that's the idea behind oxygen debt. You need to catch your breath, replenish those supplies, and rest. A long, hard effort can take days to recover from.

Anaerobic training, as I understood it, was about learning to sustain a demanding effort for longer.

Unfortunately, getting that anaerobic training effect means working very hard, at a high heart rate. These workouts are tough. At roughly 160 to 180 beats per minute, both aerobic and anaerobic processes are being trained; at higher rates, the anaerobic contribution grows.

Intervals and progression runs are ways I worked on that ability. More about those later. They matter because they help develop speed. And sooner or later, believe me, you start wanting speed.

Out running, I sometimes find myself beside a bicycle or an electric scooter, a bus or a streetcar, or even a motorboat moving along the river. They usually travel much faster than I do. Some have the unfair advantage of an engine. For a short stretch, though, I try to keep up, pull alongside, perhaps even pull ahead. I call it switching on lion mode: a brief burst at a pace I don't normally run.

There's an extraordinary thrill in passing a cyclist and staying ahead of the startled rider for a hundred or two hundred meters, sometimes longer. I love lion mode.

When the burst ends and I can't hold the pace anymore, I try not to stop completely. I keep jogging more slowly and see whether I can catch my breath while I keep moving.

Pain and suffering

At first I focused on just two things: showing up and avoiding injury. Don't rush. Don't chase speed, distance, or overnight results. Give your body time to get used to the work, and you can keep going without setbacks. The aches and misery will fade.

Then I could start thinking about how to structure my training.

Coaches talk about running at a low heart rate, and millions of runners do it. I decided to give it a try. Training harder than I could handle would hurt more than it helped. Did I want a useful workout I could enjoy, or did I just want to suffer? Easy choice.

Every running book seemed to say the same thing: don't rush. Such simple advice. So difficult to follow. I'll explain why.

Once I started running regularly, the apps showered me with records. Longest run! Fastest kilometer! Best 5K! Fastest mile! Best 10K! It felt as though everything was going wonderfully. Why stop? Why not join the race against yesterday's self and go a little faster? I had the energy.

But constantly chasing those records made ordinary training too intense. I was back to gasping, a racing pulse, and aching muscles, without a useful reason for it. Those feelings had been understandable when my out-of-shape body first had to work. Now, on an easy day, they were a sign that I had overdone it.

When I get behind the wheel, I sometimes ask myself: am I going to take risks today, or drive safely? The answer is always safely. I applied the same logic to running. I'd reserve the really hard efforts for particular occasions when I deliberately tried to run farther or faster than before: an important test or race I had prepared for. That was where the suffering belonged, if it came at all.

I made a deal with myself: ordinary training didn't have to hurt. That was how I got interested in low-heart-rate running.

Runcoins and heart-rate zones

Your heart rate responds to how much oxygen your body needs. During sleep, an ordinary person's heart might beat 50 to 70 times a minute. Run flat out and it works flat out too: 180 to 200 beats a minute, or more. Athletes may have different numbers, but these are rough ranges for ordinary people like me.

The number of heartbeats per minute is the heart rate, usually written as bpm.

Within that range, your body responds differently at different levels of effort. Those bands are heart-rate zones.

It took me a while to make sense of them. Eventually I came up with a money analogy. Money is a language most of us understand. Here goes.

Imagine a special running currency called runcoins. You can earn them, spend them, save them, or squander them. Much like ordinary money.

1. You're still living with your parents, or staying with Grandma. Someone feeds you, looks after you, and takes care of the everyday stuff. You rest and build up your strength. Money isn't much of a worry: if you need some, the family will give you a little spending money. You can read, meditate, and make plans, but you won't get very far with your grand ambitions yet. Or save much. That allowance is tiny.

This is the white recovery zone. Everything is calm. You're effectively resting, although you might be jogging very slowly. Pleasant enough, without doing much to develop your running. In this little story, you neither earn nor spend significant runcoins.

It's the stage before the harder aerobic work begins.

2. Now you leave home and begin supporting yourself. You get a job and start paying your own way. Your parents leave you a small emergency fund, so you have a little in reserve.

You don't have much experience or much money, but you don't need much either. You pick up odd jobs that cover coffee, movies, games, and a little fun. You live on fast food and candy, buying it and eating it right away. Tasty, convenient, easy. Life isn't especially stressful.

This is the blue heart-rate zone. Aerobic energy production is underway. Your body is using oxygen, and there's enough to go around. Demand is still modest, so consumption is too. Readily available carbohydrate, stored as glycogen, supplies the energy. Nothing feels particularly hard.

Still, spend a little time here and let the economic machinery get going. You've crossed the aerobic threshold and started running.

You start saving a few runcoins and feeling more confident. You're getting the hang of earning them. Why not aim a little higher?

3. You find a steady job. There's noticeably more money, enough for more interesting things: a car, a place to live, a vacation. You work for it, but success makes you ambitious. You want more, you're getting more, and, best of all, your earnings still cover your needs. Plenty of runcoins flow in and out.

You also notice how much unnecessary stuff you own. Gradually you sell it. The clutter becomes extra runcoins. Your home changes, slowly but visibly, into a more spacious, comfortable place. That extra cash pays for a little fun and a few things worth having.

Your eating habits change too. Less fast food, more balanced meals. You realize you could save that chocolate bar for an emergency snack rather than eat it immediately. You start building a reserve, and the reserve grows.

Life feels good. You could happily stay here for a long time.

This is the green aerobic zone, where you build endurance. Your body is using plenty of oxygen, drawing energy from both carbohydrate and fat. As you use up fat reserves, you get leaner, build endurance, and look better. Good for your health, too. This is where I feel I'm making real progress. My favorite zone.

But I start wanting more. Now I want more speed.

4. You earn a respectable professional salary, but you also spend a lot. Eventually you reach a curious point where expenses exactly match income. You occasionally use a credit card, but pay it off promptly. The little loans don't yet disturb the balance.

It's a fine balance, easier to imagine than to calculate down to the last cent. You're earning just enough to cover what you spend. Life is stressful, but you're keeping it together. Barely. Well done.

Congratulations! You've found your anaerobic threshold.

Your meals become erratic. You work too much to sit down regularly and eat properly. A balanced meal here, fast food there, emergency supplies whenever hunger catches you. Anything quick. There are still enough runcoins, but only just.

This is my yellow threshold zone, the narrowest band: a little below and a little above that balancing point. Another five or ten beats per minute can take me out of it in either direction.

In running terms, this is the zone for tempo work: holding your pace around the anaerobic threshold.

5. Your ambitions keep growing. You want the glamorous life: expensive purchases, grand projects, something to satisfy your ego.

It costs a fortune. You need more runcoins than you can earn. Even your whole salary, plus anything you earn on the side, won't cover it. You spend the savings accumulated in the green zone, then start borrowing. A little at first. Then more.

You spend everything you can get, until it runs out. In this analogy, everybody's runcoins run out eventually. The question is when. An experienced runner with something in reserve may have enough credit to reach the finish. An inexperienced runner can go bankrupt halfway through and hit the wall.

During this glorious spree, you eat and drink whatever you can reach. There's barely time to sell off the clutter, though you might sell a few things for whatever you can get. Fast food, rich meals, random snacks: anything available. Too busy to shop, you raid the cupboards you stocked earlier. Chocolate bars, honey, everything.

Welcome to the red zone. Beyond the threshold, ordinary aerobic production can't keep pace with the demand. The aerobic machinery doesn't switch off; it keeps working. But I rely increasingly on additional anaerobic production to cover the gap.

You're breathing as deeply and quickly as you can. Your heart is hammering. Yet lactate keeps building up and the effort becomes harder to sustain. You're taking on an oxygen debt, one you'll have to repay by easing back into the yellow or green zone.

A good credit history helps. Work steadily beforehand, meet your obligations, and the bank may offer a bigger loan for longer. Spend your green-zone years slacking, and the credit line is smaller and shorter.

Keep spending like that and runcoin bankruptcy gets closer. What I want from training is more time before it arrives: the ability to keep pushing a little longer.

Still, running in the red zone is an important part of training. It builds your ability to tolerate that hard effort and the lactate accumulating alongside it: the debt in our analogy. Short, fast intervals and bursts of speed belong here. You won't get impressive results without learning to run hard. And learning takes practice.

Spend too much time in red, though, and you can wreck your credit rating - or your health. Getting back to a comfortable green may then require a long period of recovery.

Personal boundaries

Heart-rate boundaries are individual and can change with training. As an example, these were my own training zones at this point:

1. White, recovery: up to 125 bpm. Usually walking rather than running.

2. Blue, first aerobic zone: 126-151 bpm. Basic endurance.

3. Green, second aerobic zone: 152-159 bpm. Building endurance.

4. Yellow, threshold: 160-167 bpm. Tempo running and long intervals.

5. Red, high intensity: 168 bpm and above. Hard intervals, accelerations, and learning to sustain demanding efforts.

I could spend more than an hour in what my own zone system labeled red. Over time, I had built a good credit history and learned to afford those expensive runs.

Eventually I began to think I could tell, without a monitor, whether my pulse was rising or falling. I'd glance at the watch just to confirm my intuition. Naive. That feeling is deceptive and often lets me down. I still don't entirely trust it. I can feel wonderful while my heart rate has crept up, and I want to notice that in time.