1. Rehydrating with sports drinks
If marketing hype is to be believed, we should be drinking sports drinks before, during and after workouts, but these are often actually full of sugar and far from healthy. The average gym-goer certainly doesn’t need them.
“Many sports drinks contain as much as two-thirds the sugar of fizzy drinks,” Lambert told The Independent, adding that water, in addition to a good pre- and post-workout meal, will hydrate you perfectly
To calculate how much water (in litres) you need over the course of a day, multiply your weight in kilograms by 0.03. So if you weigh 60kg, you should drink around two litres a day.
“Dehydration is a key contributor to post-workout fatigue so after exercise,” Lambert says. “Check the color of your urine to see if you need to hydrate further. If it’s darker than apple juice, you definitely do.”
2. Taking supplements for nutrients
Although sometimes important for people with specific medical conditions, supplements should never replace real food.
“One of the most common post-workout mistakes people make is to believe that a synthetically produced vitamin is the same as a nutrient found in real food,” Lambert says.
“All too many people believe multivitamins can make up for an unhealthy diet and justify an unhealthy meal post-workout. Supplements, no matter how effective, can never replace a healthy lifestyle with real food, exercise and good sleep.”
3. Choosing low-fat or diet foods
Although for years, low-fat foods were considered the key to losing weight, it’s now been realised that not only is fat essential for keeping you full, low-fat alternatives are often laden with sugar to improve their taste.
“Rather than keep you full, low-fat products are likely to make you hungrier, so you end up eating even more,” Lambert explains. “Instead of low-fat or ‘diet’ foods on the go, try and opt for some fresh fruit instead.”
4. Overestimating how many calories you’ve burned
Many people undo all the hard work they’ve put in in the gym by having a huge, unhealthy meal afterwards. Exercising does not magically supercharge your metabolism.
“Research regularly demonstrates that both normal and overweight people tend to overestimate the number of calories they burn during exercise,” Lambert says. “However, exercise is still crucial for overall health and can help you lose weight. It’s just not as effective at burning calories as some people think.”
If you’re trying to lose weight, you need to create a calorie deficit by burning more than you consume, but this varies from person to person. Even if you’re eating healthy foods, consuming too much will prevent you losing weight, so Lambert says it’s key to watch your portion size.
Following an extremely low-calorie diet isn’t wise either, as this can slow down your metabolism and lead to muscle loss.
5. Obsessing over the number on the scale
Any fitness expert will tell you that when trying to lose weight, you should step off the scales and assess your progress using a measuring tape - as muscle weighs more than fat, you should focus on your changing body shape.
Lambert points out that your weight can fluctuate by as much as two kilograms over the course of the day, depending on how much food and liquid you’ve consumed. And for women, hormonal variations can lead to water retention too, which affects the number on the scale.
6. Not eating enough protein
When working out, you’re essentially breaking down your muscles, so it’s crucial to consume protein afterwards to rebuild them. Studies have shown that eating protein can help increase muscle mass and strength - it keeps you feeling full too.
“If you’re physically active, lifting weights, or trying to gain muscle and strength, then you need to make sure that you’re getting enough protein,” Lambert says.
She advises being cautious of protein shakes and bars though, as often they may have necessary added ingredients and artificial sweeteners which won’t nourish your body .
“Sometimes they can be a convenient way to refuel on the go but you have to be savvy with reading the nutrition label and know what to look out for.”
7. Skipping a meal
Current science suggests there’s an anabolic window post-workout where eating will ensure your body reaps the best rewards from your exercise - the jury is still out as to how long this window lasts though.
But Lambert says skipping a post-workout meal would be a mistake, and she advises eating within 45 minutes of finishing exercising.