Breaking Stuff: Time Your Carb Intake to Optimize Your Training

Every time we run, we’re effectively breaking a bunch of stuff in our bodies. And until it gets fixed, there’s no way we can go out and run again at our best.

For some reason, many runners have trouble believing this.

Knowing how to train is easy. Just buy a good book and adapt its methods to your ability and experience.

Fixing what’s broken is harder.

What follows is recognized running wisdom. You’ve likely heard it before. But I’ll suggest a simple twist that will make it easier to manage your recovery. (An excellent summation of the science is Hammer Nutrition’s Endurance Athlete’s Guide to Success.)

After running hard, you can accomplish a major part of the repairs in just 30 minutes. Simply eat a recovery meal of 4 parts carbs to 1 part protein, or drink a prepared formula such as Hammer Nutrition’s Recoverite. Then eat a balanced meal 1-2 hours later that emphasizes carbs. Replenishing carbs immediately after the run has important consequences.

What happens when we fail to “carb up” after we run?

“I’m miles from home. I forgot the Recoverite. No problem, I’ll wait until dinner and catch up on carbs then.”

Oops. Coaches and exercise scientists are unanimous in stating that any delay beyond 30-60 minutes in restoring carbs after the run can set back our recovery not merely by hours, but by days.

That’s because it’s the carbs we take immediately after a run that set us up to enter the next run fully fueled.

Here’s the inside story. Those post-run carbs go straight to the liver, where the body stores them as glycogen. The body won’t touch those liver glycogen stores until we exercise again. It essentially saves them for the next run.

Any carbs the body needs between runs, it can take from glucose circulating in the blood. To keep our blood glucose high enough for normal daily activity, we only need to eat moderate amounts of fruit, beans, and other carb-containing foods.

That’s why the post-run recovery smoothie is so very important. If you carb-up adequately after you run, you’ll be (almost) nicely setting yourself up to start the next run fully fueled.

“Almost,” because it’s important to top-up the carbs circulating in your bloodstream before you run again. Three to four hours before your next run, eat 200-400 calories of complex carbs, possibly with a little protein, but no fat, especially no saturated fat. (Fats take a long time to digest, and can interfere with the body’s ability to convert carbs to glucose.) Any kind of carbs will do, e.g., potatoes, a bagel, a couple of running gels, bananas, dates, etc. Whatever you choose, it should be easy to digest.

It’s important to go into every run well-fueled. Runners who eat a low-carb diet between runs, perhaps hoping to avoid gaining weight, find their bodies playing catch-up at the start of the run. It can take 30 minutes or longer for the carbs in any gels, etc. that we ingest while running to refuel our leg muscles sufficiently for running at a productive training pace.

“Running on fumes” at the start of a run is unpleasant – you feel sluggish, slow, and unenthusiastic. The brain and heart are the body’s most carbohydrate-hungry organs. The body ensures the survival of those vital organs by never actually letting us run out of carbs. When supplies run low, the body holds back a reserve and refuses to relinquish it for running. The result is that running becomes uncomfortable and slow.

While it’s true that the body can convert fats for energy, this ability appears to be highly individual. Ian Jackson, my roommate in the early 1970s, once ran 140 miles in 7 days – 20 miles per day, over hilly terrain in the Berkeley hills – at sub-6-minute pace while fasting on plain water. Ian obviously had a phenomenal ability to convert fats for energy, perhaps the result of unusual genetics and his long history of competitive swimming. For most runners, burning fats is a slow, inefficient process that can’t satisfy the energy demands of normal training.

Timing your intake of carbs for optimal recovery will help you keep your weight down, because you won’t have to carb-up the evening before your longer or harder runs, and you won’t need to eat a high-carb diet generally.

(An exception is high-mileage elite runners – the world-leading Kenyans, for example, get roughly 75% of their calories from carbs, versus just 50% for U.S. elites.)

That’s good news for us non-elite runners who struggle to control our weight. Nothing puts on weight faster than eating too much carbohydrate, particularly sweets and starchy foods (potatoes, white rice, white flour, etc.). Consumed outside of the body’s 30- to 60-minute post-run carb-restoration “window,” excess carbs swim eagerly to our butts and guts, where they plant themselves and are hard to budge. Eat starch today, and you’ll surely wear it tomorrow.

A wise carb plan will go a long way toward repairing the damage of running. But of course, it isn’t the only “fix” that’s required.

You’ve probably had this experience. You stoked up on carbs immediately after a long run, and again 3-4 hours before your next run. You started the run feeling well-fueled, but you sensed that something wasn’t quite right. Your legs felt like they had enough energy, but your body didn’t want to run faster than a jog. You may have also noticed that your muscles were still a bit sore from the last run.

What’s going on? Congratulations, you’re doing a great job with your fueling strategy, but let’s face it, you simply weren’t fully recovered.

So – what to do?

Think of it this way. When we break stuff in our bodies by running, we don’t break just one thing (depleting carbs). We break lots of things, and they don’t all get fixed at the same time.

Replenishing carbs is a major, extremely important part of the repairs, but it isn’t everything. For example, after a very hard run, it takes the body two weeks to resynthesize proteins sufficiently to fully mend the damage and increase our fitness. It’s why many runners find success by running very hard or long no more often than every 14 days.

In fact, there’s very little you can do to make your body repair the damage any faster. You can tinker with massage, dietary adjustments, supplements, and electrical muscle-stimulation, and these things can all help greatly. But beyond a certain point, the main thing your body needs to complete its repairs is rest.

That’s why every athlete needs easy days. In fact, the worst mistake a runner can make – and it’s a classic blunder that we all seem destined to make at some point in our career – is to run a tiny bit too hard on the so-called easy days, so that the “easy” days become “half-hard” days.

Big mistake! It pays to remember that any energy we expend our recovery days, above and beyond what the body can safely handle, will not make us fitter, but will only interfere with our improvement, and will be subtracted from the energy we could expend doing solid, hard training, later.

Half-easy recovery runs don’t work. They are just plain dumb, and they’re a sure recipe for failure. Runners who push too hard on their easy days only succeed in slowing their progress, or even “improving backward,” destroying whatever gains they’ve achieved.

How easy should you train on your recovery days? And how many easy recovery days does your body need? How can you tell?

In fact, it’s not difficult. Your body has a built-in feedback system that will tell you, with impressive accuracy, exactly how far and hard it can run and still repair the damage and improve. It will tell you, very precisely, how you should train on the easy days in order to make the most rapid possible fitness gains.

How does the body talk to us? By inner feeling.

When we get sick, we feel lousy. And when we’re well, we feel great – full of energy and enthusiasm. Knowing how to train is as simple as listening to the inner feelings through which the body continually talks to us.

When you run at the pace that your body can safely handle, the pace that allows the body to optimally improve, you’ll feel a deep, subtle sense of harmony. You feel un-rushed, centered in the moment, and able to enjoy the run. That’s your body’s way of saying “Aaaahhh – thank you!”

But if you run even a little faster, you’ll feel ever so slightly out of tune. There will be a subtle sense of strain, tension, and disharmony. On recovery days, it can feel as if you’re having to push a bit to maintain what may even seem like a ridiculously slow pace.

Many runners ignore these subtle hints from the body. Some runners ignore them for years. As a consequence, they’re never truly recovered and fail to realize their full potential.

Listening to the body isn’t for sissies. It’s a tough discipline, very exacting. It demands self-control, inner strength, and above all, maturity – defined as the ability to accept reality as it is, and deal with it accordingly.

Fortunately, repairing our broken-down bodies doesn’t have to mean endless days of un-enjoyable slogging.

Try this experiment. On your easy days, listen to what your body is telling you, and run accordingly. You’ll find that a wonderful thing happens. For starters, the easy runs, which many misguided runners feel are a waste of precious training time, will become deeply enjoyable.

That’s your body talking to you. When you do the right thing, the healthy thing, the thing that allows your body to improve, the body rewards you with wonderful feelings of harmony and health.

You’ll find that this works very reliably. Moreover, those vibrant feelings aren’t the only benefit of training with discipline and control, in harmony with the body’s needs.

You’ll also discover that on your scheduled hard days, you’re able to run harder and longer than if you compromise your recovery by running a bit too hard on the easy days. And the hard days will feel wonderful, too – not forced or strained, but exhilarating and energized.

There’s a good argument to be made for starting every run slowly, even the hard ones, and cautiously “working up” the pace, instead of starting fast and then backing off when you discover that your body isn’t responding because it isn’t fully recovered.

Exercise scientists know that the body “likes” a long warmup, because it gives the muscles time to warm up to the temperature that’s required for fast, efficient running.

A long warmup also gives us a chance to tune in to the body and listen to its messages. Blasting off at the start can make it harder to interiorize our attention and hear those messages. Fast breathing and a rapid heart rate can interfere with concentration and draw our attention outward, at least at the start of a run, before we find our rhythm.

A long warmup sets a healthy tone – it puts our heads in a relaxed space, where we can monitor the body’s needs for the day.

Start at a gentle pace that the body can handle effortlessly. Let the body take the lead. When it wants to go faster, it will let you know. After a reasonable warmup, speed up tentatively. When your body is ready to go faster, it will feel like you’re falling effortlessly into the faster pace.

Wise running – doing what the body can handle – pays off at both ends. The easy runs and harder runs both become much more enjoyable and productive.

Isn’t that a sane way to train?