Exercising is a great idea most of the time, but there are exceptions when it’s better to play your get-out-of-gym card. Let our expert guide help you decide.
You’re way overcaffeinated
GIVE YOURSELF A PASS Although having some caffeine in your system before a workout may improve your athletic performance – the chemical can stimulate your central nervous system to give you more juice – when you’re overcaffeinated, you may feel dizzy, jittery, nervous or even experience some stomach problems. Add in exercise and those symptoms can become exacerbated, explains Edward Ryan, an assistant professor of exercise science at Chatham University.
Plus, being hopped-up on caffeine may actually impair your recovery during high-intensity exercise, because your heart rate isn’t slowing to its usual recovery level during rest intervals.
Instead of revving your body on high, head for a stroll, keeping your heart rate below 60 per cent of your max effort. You won’t be able to walk off the physical jitters – burn ing calories won’t help your body metabolise the caffeine any faster – but moving at that easy pace will at least give you a hit of mental calm.
Your stomach is empty, or you just ate a huge meal
SWEAT IT OUT Unless you typically experience stomach cramping, light-headedness or nausea when working out on an empty or full stomach, exercise can actually beneﬁt you, says Brittany Allman, a sports nutritionist at Florida State University. “We have enough stores of energy to last us through a workout even without food in the tank,” she says. “And running on empty may actually help you burn more fat.”
That’s because when you exercise, if there are no carbs readily available for your body to burn, it turns to its muscle glycogen (the stored form of carbohydrate) and its fat stores to use as energy. (The jury is still out on whether fasting before a workout saps your energy; some research says yes, some says no.) On the ﬂip side, when you’re fully fuelled, exercising can improve digestion by helping your body move food from the stomach to the intestines, Brittany says. So if you can deal, start burning off that pie.
What’s optimal for workout fuel? Having 150 to 300 calories one to two hours before your session. Make it a combo of carbs for quick energy and a little protein to help prevent muscle breakdown. A banana and two tablespoons of peanut butter should do the trick.
You have a job interview or a presentation in a few hours
SQUEEZE IN A WORKOUT For people who exercise regularly, doing it the morning of a big task can improve your memory and lower your stress levels, according to research in the journal Neuroscience. After one month of brisk walking or jogging four times a week for 30 minutes, those who also exercised the morning of a series of mental tests performed better than the habitual exercisers who skipped their a.m. workout. “Exercise can help with cognition by increasing the levels of brain-derived neurotrophic factor, a protein that supports the growth of new brain cells,” says lead study author David Bucci, a professor of psychological and brain sciences at Dartmouth College. And the more aerobic, the greater the impact. A short, brisk walk could have cognitive benefits that help you ace an interview or deliver a flawless speech.
You did Crossfit today, but your friend invited you to take a bootcamp class tomorrow morning
SKIP IT Depending on the WOD that day, you may have temporarily tapped out your muscles for more heavy lifting so soon. After a tough resistance workout, your muscles need 24 to 72 hours to repair tiny micro tears and to add the proper amount of amino acids needed to increase your strength, says Michele Olson, a professor of exercise science at Auburn University in the US. You may be doing more damage to the muscle if it hasn’t had time to heal, and your performance may be compromised, setting you up for injury. Instead of bootcamp, do a moderate cardio workout like a 30-minute run, which will increase circulation to your muscles while giving them a break from doing reps, Michele says. Keep in mind, though, that if your Crossﬁt workout hit only your upper body, it’s ﬁne to do a lower-body strength workout the morning after, or vice versa.
A short, brisk walk could have cognitive benefits that help you ace an interview or deliver a flawless speech.
Crampy? Pick an aerobic activity and aim for 60 to 90 per cent of your max heart rate to ease the pain.
You’re mentally exhausted after putting in long hours at the office
LACE UP When your brain is fatigued, your body is still physiologically capable of working at its maximum capacity, according to research at the Universite de Bourgogne in France. The caveat: “While you can still lift the same amount of weight and run at the same top speed when you’re mentally tired, the difference is that endurance exercise will actually feel harder, thereby reducing your performance,” says researcher Benjamin Pageaux. That’s not necessarily a bad thing, he adds. Training when you’re feeling burned out might actually toughen you up in the long run, so you can better resist the desire to slow down during your next race, he says.
You have really bad cramps
HIT THE GYM Exercise can minimise monthly cramps, so much so that you may not feel the need to pop that OTC pain reliever, says Dr Pinar Kodaman, an assistant professor of obstetrics, gynaecology and reproductive services at Yale University School of Medicine. When you exercise, the production of prostaglandins – cramp-inducing inﬂammatory chemicals released in the uterus during menstruation – is suppressed. To best net the effect, go with cardio, like running or cycling, she suggests.