Is Aerobic Exercise Really Necessary For Fat Loss?

Is it necessary to perform cardiovascular exercise to get lean? The answer is yes and no. It is well known that a caloric deficit is required to lose fat. This can be accomplished with or without exercise. Exercising allows you to eat more. No exercise requires you to consume less in order to meet a caloric restriction.

Exercise is primarily required while dieting in order to boost your metabolism, which slows down to compensate for the caloric deficit. Although weight training accomplishes this better than anything, it is also the most taxing on the body. Combining a couple of weight training days with moderate aerobic training can stimulate your metabolism without putting too much strain on the body. It is arguable that the best results can be obtained by including both weight training and aerobics.

Your body type will dictate whether you require cardiovascular exercise. If you are an endomorph with significant weight to lose then moderate aerobic training will be very important. The leaner you are, the less important it is and the more you can rely on diet to attain your desired weight. For overweight individuals, frequent sessions - up to five to seven times a week - may be appropriate. Leaner individuals can get by with one to three sessions.

If you choose to include cardiovascular exercise in your program, when is the optimum time of day to perform that exercise? In the morning or in the evening? Should you perform cardio in a fasted state or not? Both of these questions are hotly debated. Some believe that morning cardio is ideal to increase metabolism and get the “fat-bu
ing fire” going early in the day. Glycogen stores (energy stored in the muscles) are low in the morning, which creates higher fat burning during the session. With respect to performing cardiovascular exercise in a fasted state, some people believe that performing on an empty stomach will force the body to burn a higher percentage of fat.

While both of these statements are true, keep in mind that fat loss is the result of total energy expenditure (energy in versus energy out) not what you are burning at any particular point in time. Aerobic exercise, especially done at a high intensity, is not much fun when you are hungry or half asleep during the session.
What is most important is performing the session when you will get the most out of it. If you are energetic in the morning, do it then. If you are at your best at a later time of day, then perform your cardio then.

Finally, it is best to perform weight training and aerobic work on separate days, or least on a morning/evening split to give the body some rest and recovery time. Causing the body to adapt to too many things at once, especially while in caloric deficit will almost certainly create a plateau and sub-optimal results.