You're in the middle of a long workout and you're wondering how in the world you're going to muster up enough energy to finish. We've all been there. It's as though someone has unscrewed the cap and let all the fuel out of your tank. So what should you reach for to help you comfortably finish your workout?

Sports nutrition manufacturers have come up with all sorts of new items to help you do just that. But are they really any better than the old standards: water or a banana? Before we answer that question, something to consider: There is no single solution that works for everyone. Once you explore your options, you can determine which is the best for your body's particular needs.

There are few things more essential to maintaining performance than staying hydrated throughout your workout. Water is an obvious first choice, but you may need extra energy in the form of carbohydrates to get through a particularly long or strenuous exercise session. If this is the case, energy bars or gels and sports drinks may be the answer to your depleted energy supply. What follows is a breakdown of the pros and cons of each.

Water
Water is a calorie-free source of the fluid your body needs to keep going. There is no better way to compromise performance than to exercise while you're dehydrated. Research shows that your heart rate increases eight beats per minute for every litre of sweat lost during exercise. This can occur in as little as 30 minutes of exercise depending upon the environment and your intensity. This increased heart rate, combined with inefficient cooling, causes your temperature to elevate. This not only compromises performance, but can lead to heat illness as well. Most experts recommend drinking at least a cup (4 to 10 ounces) of water every 15 minutes of exercise.

Sports Drinks
Activities lasting longer than one hour can leave your body wanting more than just water. Sports drinks, which typically contain about 50 to 70 calories, plus vitamins and minerals, are an easy answer to both the fluid and carbohydrate drain that comes from prolonged activity. Research shows that runners and cyclists who consume a sport drink during races not only finish more quickly, but also rate their exertion levels lower than those who consumed a placebo beverage.

It is important to realize, however that this was true only during longer-duration activities. You should be able to complete your 30-minute run or a 45-minute step class without the aid of additional carbohydrates.

Energy Gels and Bars
Energy gels are a relatively new alternative to traditional sports drinks or bars. They feel similar in texture for your stomach to digest. They typically contain about 70 to 100 calories and may also include caffeine and other ergogenic aids. Energy bars have been around forever and are eaten more often as a snack than as an energy replacement during exercise. Today, the market is saturated with numerous flavours and types, each with a different ratio of fats, carbohydrates and protein. The key is to find one that tastes good and doesn't upset your stomach.

At 110 to 250 (or more) calories each, energy bars also provide extra vitamins, minerals and fibre, which ups their nutritional value considerably. But eating an energy gel or bar is not enough. You must consume enough fluid to replace what's been lost as well as to help speed digestion.

How you choose to refuel during a workout depends on your body's reaction to what you put in it. For sessions lasting less than an hour, water is sufficient so long as you consume at least 4 to 10 ounces every 15 minutes.