The myth: To lose weight, cut carbs or fat
The truth: Most get-thin-fast plans revolve around the idea that restricting your intake of one particular nutrient, usually carbs or fat, is the best way to lose weight. But the results of a 2009 New England Journal of Medicine study suggest otherwise. For two years, participants followed one of four calorie-restricted diets with varying amounts of carbs, protein and fat. After 24 months, all participants had lost about the same amount of weight (just 9lbs).
"This study proves that calories are the most important factor for weight loss," says Tara Gidus, a sports dietitian (dietdiva.com) and marathoner. "To lose weight, you need to take in fewer calories than you burn - regardless of what percentage of carbs, protein, or fat you're eating." So followers of Dr Atkins et al, take note: gimmicky diets just distract us from this simple truth.
The myth: You should try to exercise in the fat-burning zone
The truth: The ‘fat-burning zone’ lies between 50 and 70 per cent of your maximum heart rate. When you exercise at this low intensity, your body draws energy from fat. As your heart rate goes up, more energy comes from carbs. So it seems logical that to lose fat you should keep your heart rate low, says exercise physiologist and running coach Jason Karp (runcoachjason.com). But that’s not actually the case.
“Running at higher intensities causes you to burn a lower percentage of fat calories in favour of carbs,” says Karp, “but you use more total calories.” And that’s the key to slimming down. Plus, as you torch more calories, the amount of fat burned increases. So it pays to pick up the pace.
Of course, lower-intensity exercise still has its place. Long, slow runs build aerobic fitness and endurance. But to kickstart a sluggish metabolism, you need intensity. Karp suggests interval training (condensed runs that combine intense efforts with recovery) because studies have found these workouts burn more calories during and after exercise. “It also cuts down on boredom,” he says, “which means it’s more likely you’ll stick with your programme.”
The myth: Mini-meals are better than three hearty ones
The truth: So many dieters wrongly believe that eating several small meals throughout the day is a guaranteed way to banish hunger – and eventually blitz that belly. But scientists have not turned up substantial evidence that eating more often really helps, according to a review of research by scientists at Newcastle University and Griffith University in Australia. In fact, a 2009 study of over 10,000 subjects reported that between-meal nibblers were 69 per cent more likely to pack on pounds over five years.
Frequent eating only works if you choose nutritious foods and are forever vigilant when it comes to controlling portion sizes. After all, it’s not hard to turn six small meals into six large ones. Again, it all comes back to calories. “You can eat three times a day or 10 – as long as you have the same calorie intake that will induce weight loss,” says Gidus.
Still, runners do need their snacks. Eating something small before heading out for a run, followed by a post-run snack or meal, can improve both your performance and recovery.
If you run at lunch, nibble on some dried fruit or yoghurt before heading out, and eat a mix of carbs and protein afterwards, perhaps something like a turkey sandwich, or some salmon and couscous. For the rest of the day, Gidus recommends tuning into your hunger to tell you when to grab a knife and fork.
The myth: Eating at night causes weight gain
The truth: Many runners believe their metabolism plummets later in the day, which is when we often succumb to the temptation of foods that are nutritionally suspect. But a calorie is a calorie no matter when you eat it, says Gidus. “As long as you don’t take in more calories than you burn in a day, you won’t gain weight.” She adds that overeating at 9pm is actually no more heinous a crime than overeating at 9am. “You may have a slightly higher metabolism earlier in the day, but all things considered, the impact on weight loss
is fairly trivial.”
If you train in the evening, eating at night actually has its advantages: “You have to eat a well-balanced meal to encourage recovery, no matter how late it is,” says Gidus. As long as you don’t gorge yourself, you’re not in much danger of gaining weight. Common sense, as ever, is important: if you routinely spend too much time in the evening with tubs of Ben & Jerry’s ice cream, you’re eventually going to sabotage your efforts.
The myth: Lift light weights with more reps to get toned
The truth: Runners who want to look lean and toned often skip heavy barbells in favour of lighter weights with lots of repetitions. But that won’t give you the physique you’re after. If you want to get toned, you need larger muscles and less fat. “And challenging your body through heavier lifting is a big part of this equation,” says New York-based running coach Monica Vazquez.
In fact, a study at Georgia Southern University determined lifting 85 per cent of your maximum ability for eight reps burns about twice as many calories in the two hours post-workout, compared with 15 reps at 45 per cent max. And don’t worry: lifting heftier iron won’t transform you into an Arnold Schwarzenegger-alike. Achieving that look requires eating a high-calorie diet and a longterm power-lifting regime – which you won’t be doing. “If you’re creating a calorie deficit, you simply won’t bulk up like a bodybuilder,” says Vazquez.
You don’t need to give up lighter weights altogether – they do a better job at improving muscular endurance. It’s all about striking that optimum balance, says Vasquez. “A solid resistance programme should include periods of both high and low reps.” She suggests doing higher reps (12-15) and lower weights for about four weeks and then switching to lifting heavier weights for fewer reps (eight to 10). “Alternate monthly after that to keep the stress on the body constantly changing.” Muscle responds to resistance, so if it’s too light, you won’t see good results. A little bit of pain – or a healthy bit of grunting – is the secret to correct kind of gain here. “You should struggle to eke out those last few reps,” she says.