Is aerobic exercise needed to lose weight? The answer is yes and no. It is widely accepted that we need to establish a caloric deficit to lose fat. This can be achieved with or without exercise. More exercise means we can eat more. Not exercising means we need to eat less to meet our calorie restriction.
The main reason to exercise while dieting is to stimulate your metabolism, which slows down to compensate for the lack of a food source. While weight training accomplishes this better than nothing, it’s also the most taxing on the body. Supplementing a couple of days of weight training with moderate aerobic training can boost your metabolism without putting too much strain on your body.
In the end, it all comes down to body type. If you are an endomorph with a lot to lose, moderate aerobic training will be very important. The thinner you are, the less important it is and the more you will depend on diet to achieve your desired weight. For heavier people, frequent sessions, five to seven times a week, may be appropriate. Thin people can get by with one to three sessions.
Whether or not you choose to include aerobic work in your program, I believe you’ll get the best results by including both weight training and aerobics. Try it yourself and your results will tell you.
Many people wonder when they should do their aerobic activity. at morning or evening? In a fast state or not? Both questions are hot topics for debate. Some believe morning cardio is great for boosting metabolism and kick-starting fat burning earlier in the day. Glycogen stores (energy stored in the muscles) are low in the morning, resulting in more fat burning during the session. Some people believe that performing on an empty stomach will force the body to burn a higher percentage of fat.
While both of these arguments are true, it should be understood that fat loss is a result of total energy expenditure (energy in versus energy out), not what you are burning at any given time. Also, aerobic exercise, especially if it’s high intensity, isn’t much fun, especially when you’re hungry or half asleep during the session.
What it really is about is doing the session when you get the most out of it. If you have energy in the morning, do it then. If you’re at your best later in the day, then that’s your time.
On a final note, try to keep weight training and aerobic work on separate days or at least a morning and evening split so they don’t interfere with each other. Forcing the body to adapt to too many things at once, especially while in a caloric deficit, will almost certainly lead to stagnation and suboptimal results.