The literal meaning of the word "aerobic" is "in the presence of oxygen". The term "anaerobic", in contrast, stands for "in the absence of oxygen". In the context of physical exercise, aerobic activity refers to any moderate-intensity, sustained workout carried out steadily for a minimum of 30–40 minutes so that it places on the heart a significantly increased demand for oxygen. Brisk walking, jogging, swimming, cross-country skiing, cycling are some examples of aerobic exercises – in fact, any other activity employing large muscle groups can be considered aerobic if performed at moderate intensity for extended periods of time.
Anaerobic exercises, on the other hand, involve repeated, intensive exertion of muscles in short bursts (of not more than 2 minutes duration each), with some recovery time allowed between two repetitions. Heavy weight lifting, strength training, resistance training, sprinting, etc., are some examples of anaerobic exercises. In short, anaerobic exercises involve short bouts of intense activity in contrast to long, slow-and-steady sessions of moderate-intensity workouts constituting aerobic exercises.
Benefits vs. Limitations of Aerobic and Anaerobic Exercises
During aerobic exercises, except for a brief initial period where glycogen is used as a fuel, fat metabolism is initiated to meet the energy requirement of the muscles involved in exercise. And since fat metabolizes in the presence of oxygen, aerobic exercises make the heart muscles work that much harder, strengthening them in the process. That is why they are also referred to as cardio workouts. Other benefits include strengthening of the muscles involved in respiration, toning of the body muscles in general, accompanied by reduction in the fat percentage in the body.
Aerobic exercises also confer many performance benefits: for example, enhanced stamina and endurance, increased ability of the muscles to use fat instead of glycogen during intense exertion, speedy recovery from muscle fatigue during intense exercise, and so on. On the flipside, aerobic exercises do not directly help build strength, power and muscle mass that a bodybuilder desires. In fact, excessive aerobic activity may result in undesirable loss in muscle mass, strength and speed along with the desired fat loss.
However, even though aerobic exercises cannot achieve significant muscle mass buildup, they do prepare the muscles for enduring the intense exertion in strength- and muscle-building anaerobic exercises.
As anaerobic exercises are extremely intense and fast, the energy requirement of the involved muscles cannot be met with the slow, oxygen-dependent (aerobic) process. Instead, a fast anaerobic process comprising creatine-phosphate–ATP conversion in the initial stages and glycogen breakdown thereafter is utilized for meeting the energy requirement of the intensely exerted muscles. But this process leaves behind lactic acid as a byproduct, accumulation of which causes muscle fatigue – hence the need for recovery period in anaerobic exercises, during which lactic acid is removed and the muscles are ready for another bout of exercise.
The results achieved by anaerobic exercises like weight lifting and strength training are exactly what a bodybuilder desires: low body fat percentage, buildup of muscle mass, and increased strength, power and speed. In fact, increased muscle mass helps burn more fat even when you are doing nothing. However, the only flipside of anaerobic exercises, if one may call it so, is that they require a strong foundation of aerobic fitness to begin with – otherwise you would tend to, as they say, “hit the wall” quickly.
Aerobic or Anaerobic?
If you are an aspiring bodybuilder, you may often be confronted with the controversy of aerobic vs. anaerobic – Which one is better for you? Well, as a bodybuilder you not only require to build muscle mass, strength, power and speed but also need cardiorespiratory endurance, flexibility, agility, stamina, and speedy recovery of the strained muscles.
The answer to the question “aerobic or anaerobic?” is, therefore, obvious: There is no choice to be made between the two; it’s got to be both aerobic and anaerobic if you want to be a successful bodybuilder – aerobic for enhancing cardiorespiratory endurance and reducing body fat, and anaerobic for power and muscle mass buildup.
