A man of average size stores enough fat to sustain him for days, weeks and maybe months. So why is it so hard to exercise for much longer than a couple of hours at a time? One word: glycogen. It’s glucose in storage form, and your body’s most easily accessible source of energy. You can work, sleep or paint the town red all day without ever making a dent in the glycogen stored in your muscles and liver. But the minute you ramp it up, your energy supply is on the clock.
“Most of us have enough glycogen to exercise one to three hours at most. If you’re exercising at moderate to high intensity, your levels will sink more rapidly,” says Marie Spano, a sports nutritionist who works with professional athletes. Your body will never let you use all your glycogen – there’s always some in reserve – but you’ll start slowing down when the needle nears the E. To train seriously, you need to delay that moment as long as possible.
Time Your Carb Intake
Research shows that eating the right amount of carbs several hours before a race or a multi-hour training session can maximise your glycogen supply, which boosts your endurance. To top off your tank, your pre- workout meal should include óg to 1g of carbohydrates per 1/2kg of body weight, Spano says. For an 80kg guy, that’s between 350 and 700 calories from carbs (or about two bowls of steamed rice). Which end of the range is right for you? Depends on how much time you have to digest. The longer the lag before game time, the more you can eat.
Fuel Up For Short Workouts
If you’re exercising for an hour or less, you don’t need to make special dietary accommodations. But you do need fuel to sustain yourself. Dietitian Lonnie Lowery recommends eating a simple meal with at least 200 calories, 20g protein and 30g carbs an hour or two before your workout. A grilled chicken sandwich will set you up.
Drink For Endurance
Exercise-induced dehydration slows your motor neurons; it’s as if you were making Michael Phelps swim through Jell-O. Not only do you feel fatigue sooner than you otherwise would, but your performance slips as well. Skipping liquids also means missing out on an easy-to-absorb delivery system for the nutrients your body needs during and after exercise.
Knowing how much fluid you need to replace isn’t easy. Sweat rates range from 500ml an hour to four times that. And, of course, rates fluctuate with the weather. Whatever you do, don’t rely on thirst as a gauge. By the time you’re hankering for a drink, you’re probably well on your way to dehydration.
There’s one way to know for sure if you’re drinking enough: Weigh yourself before and after a long race or training session. Almost all the weight you lose is water. Replace each 1/2kg with 680g (3 cups) of fluid. Another indicator of hydration status is your urine. If your bladder goes longer than three hours without a cry for help, you’re probably not drinking enough, Spano says. Colour matters, too; your urine shouldn’t be darker than pale lager.
Fuel Up Fast
If you have to be on the starting line first thing in the morning, and your window for digesting food is less than an hour, go for easily digestible carbs with high water content, such as bread (which contains 35 per cent water) and lower-fibre fruits like bananas. Stay away from foods that are high in protein and fat (nuts, for example), which take longer to digest than quick carbs. Also, avoid high-fibre fruits and vegetables (beans, broccoli, raisins and berries), which can cause gastrointestinal distress if you eat them just prior to strenuous exercise.
If you’re a long-haul athlete, caffeine can boost your performance, help you use more fat for energy (thus sparing your precious glycogen) and reduce post-training pain. But – and it’s a huge “but” – contrary to what most people think, you can’t reap these benefits from coffee. “There seems to be a compound in coffee that limits caffeine’s benefits,” says Jay Hoffman, a professor of sports and fitness at the University of Central Florida in the US. That’s why caffeine studies that demonstrate its benefits have involved people drinking powdered caffeine dissolved in water instead of consuming coffee.
Energy drinks are another source of caffeine. But they also pack a boatload of calories, and you’d need a PhD in chemistry to decipher their ingredient lists. Consider taking a caffeine tablet instead (or guarana supplements, which are high in caffeine), so you know what you’re consuming. Studies show benefits with 1.4mg to 2.7mg of caffeine per 1/2kg of body weight, which works out to 252mg for an 80kg guy. But stay below 300mg.
Don’t Ignore The Salt
There’s plenty of hype about the evils of salt, but avoiding it is bad advice for any man who does high-volume, high-intensity training, especially in heat and humidity. If you regularly sweat out 2 to 3 per cent of your body’s weight – 3kg for most of us – you probably need more sodium.
Reduce Pain With Juice
To protect your muscles during intense training, think dark red fruit. A recent study at Oregon Health & Science University in the US showed that runners who drank tart cherry juice for a week before an ultra-endurance challenge had less pain after the race. Tart cherries, red grapes and pomegranates are all available in juice form, and are loaded with anthocyanins, a type of antioxidant that helps reduce the muscle inflammation and damage caused by serious exercise.