If you feel like you’re about to throw up, it’s because you are,” says nutritionist Alan Aragon. Here’s why: when you begin lifting, blood flow to the muscles you’re working increases, while blood flow to your gastrointestinal tract decreases. The change in circulation can trigger reflux. If this happens while you have undigested food in your gut, there’s nowhere for it to go except back up your oesophagus.

The simplest solution…
Aragon says, is to slug a shake: liquid food can be digested much quicker. For those times when you want a real meal, make sure you eat 90 minutes to two hours before your workout so your stomach has time to break down the food and start absorbing the nutrients.

“Whatever you do, don’t head to the gym hungry,” says Aragon. Consuming a combination of protein and carbohydrates – 20 to 40g of each – before lifting increases energy, helps build muscle and prevents the breakdown of muscle protein.