Vegetable salad
Some of more than 8,000lbs of locally grown broccoli from a partnership between Farm to School and Healthy School Meals is served in a salad to students at Marston Middle School in San Diego, California Reuters/Mike Blake

Many people make the mistake of believing that any type of food is good in fueling their workouts. However, consuming the wrong things can actually hinder your cardio exercise, leading to system crashes, lack of energy or focus, cramping and even injury. Here are five types of food you should stay away from before a workout.

1. Sugary foods

Foods that are high in sugar or those that contain a lot of refined carbohydrates will spike your blood sugar. In the beginning, you might feel a sudden burst of energy and intensity. However, your system will also crash in the middle or near the end of the workout, due to sugary foods being processed quickly by your body. Some of the items to avoid before cardiovascular activity include donuts, ice cream and white bread. A study conducted at University of Otago in Dunedin, New Zealand showed how the right exercise snacks can help control blood sugar levels.

2. Fast food

Food that are high in fat tend to be digested at a much slower rate. Some experts found that it takes about four hours to digest high-fat meals, causing you to slow down in your workouts and losing strength. Many people feel sluggish after eating a full fast food meal, consisting of a hamburger and French fries.

3. Vegetable salad

Although it is a great way to avoid excess fat accumulation, eating broccoli, lettuce, cabbage and green leafy vegetables minutes before your workout can lead to gastrointestinal discomfort due to the high fiber content. You might feel like going to the bathroom in the middle of a marathon.

4. Energy drinks

Although energy drinks and gels contain caffeine or taurine which provide quick energy to help you last through the workout, many of these also contain sugar that cause you to crash midway. Drinking sugary juices or soda before a workout can also cause bloating, which will slow you down.

5. Eating nothing

Some experts recommend that you do cardio on an empty stomach to immediately tap into your fat stores. However, intense cardio exercise on an empty stomach will deplete your muscles of glycogen. You might feel lightheaded or dizzy while running or cycling or even suffer cramps or faint. A study conducted at the University of Wisconsin-Madison showed how working out on an empty stomach can impair workouts and reduce intensity.