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Ignoring pre-workout nutrition can slow down your metabolism.iStockphoto/Getty Images/iStockphoto

The simple answer is no.

Proper pre-exercise nutrition is key to getting the most bang for your workout buck. Going four or more hours with no food and then exercising can potentially decrease your metabolism, which is the last thing you want if you are trying to lose weight or firm up.

Have a question about your workout? Ask the trainer here.

Figuring out optimal nutrition timing is tricky, though. Both eating too little and eating too much will make a workout unpleasant. I've eaten too little, then tried a training run - only to find I didn't have enough energy and was dangerously light-headed. I've also trained after eating too much and felt sluggish, even nauseous.

Every person's digestive system is different, but in general your body can handle the following:

1) a small snack 20 to 60 minutes before a workout - say, half a banana before a morning workout; or

2) a larger snack one to two hours before your workout - say, an apple and a tablespoon of almond butter in the late afternoon before a 6 p.m. workout.

I often suggest to my evening clients that they save a quarter of their lunch and eat it in the late afternoon. Splitting your lunch into two smaller meals will give you energy for your 6 p.m. workout, but won't add calories to your diet.

Send certified personal trainer Kathleen Trotter your questions at She will answer select questions, which could appear in The Globe and Mail and/or on The Globe and Mail web site. Your name will not be published if your question is chosen.

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