CHAPTER 6

You Need Anaerobic Exercise

Lifting weights, sprinting, jumping and other activities that require short, intense bursts of effort are anaerobic exercises. The body needs instant energy for such work, so it generates fuel by a process that does not rely on taking in large amounts of oxygen. These activities build muscles and bones, and increase strength and speed.

PART 1 Alternate Fuel

Take three steps

Find the right weights...

“Anaerobic” means “without oxygen.” Sprinting, weight-lifting, and plyometric or jumping exercises are all anaerobic activities. The action happens in short intense bursts, so the body cannot take in oxygen fast enough to use it to produce usable fuel. READ MORE

When you start one of these anaerobic activities, your muscles use stored adenosine triphosphate (ATP), then another substance called creatine phosphate (CP) which allows it to reuse some ATP. This part of the fast-burning anaerobic process lasts only 10 seconds or so. After that, the body makes fuel from carbohydrates in a process called glycolysis. Carbohydrates are stored in muscle cells, and some other cells, as glycogen. The anaerobic pathway creates energy by using fuel stored right in the muscles, turning glycogen into ATP.

While this process is speedier than the aerobic pathway, the fuel supply doesn't last as long. It creates byproducts which result in muscle fatigue—hydrogen ions and pyruvate, which eventually result in lactic acid building up. For many decades, exercise physiologists and athletes blamed lactic acid for the muscle burn felt after fatigue. Now evidence shows that the hydrogen ions are the more likely culprit, and lactic acid may actually be on the scene to help restore balance and normal acidity after a muscle is fatigued. Once muscle fatigue sets in, it's time to rest and recover. LESS

PART 2 Tear and Repair

Just the Facts

How do bodybuilders...

Building muscle and strength are the main objectives of anaerobic exercise. Muscles become larger and have more power to contract when you continually challenge them with resistance, then let them recover, or repair.

Working a muscle against the maximum weight possible causes microtears in the muscle fibers. These tears are repaired with proteins called actin and myosin, which enable muscle cells acting in concert to contract. The cycles of “tear and repair” end up making each muscle cell more powerful, not just bigger. Also, as you train, your muscles learn to work with the nerves that trigger their action in a more coordinated manner. The result? When more cells in a muscle are “firing” at the same time, that muscle can perform more work. READ MORE

Resistance work can change your appearance, defining muscles and improving your overall tone. But the benefits are more than skin deep. Your body has a natural tendency to lose muscle mass as you age. Getting in the habit of lifting weights or performing other anaerobic work will make it easier for you to keep up your strength and lean-to-fat ratio in later years. In a 2011 study, researchers found that the greater a person's total muscle mass, the lower his or her risk of having insulin resistance, which is a precursor to Type 2 diabetes. LESS

PART 3 What Works?

It Adds Up

17.7% Percentage of US adults...

You need not join a gym nor buy a pricey set of weights for an anaerobic workout. Your resistance can be in the form of traditional weights, resistance bands, found heavy objects or your own body weight. The old gym-class standards are probably the most common anaerobic exercises of all: sit-ups, push-ups, pull-ups, and squats. READ MORE

People who have never worked out with resistance equipment before are sometimes surprised at how they feel the next day. Muscles that have been properly worked are tender and sore while they are in recovery. That feeling is a signal to your body to repair itself and get stronger. Advising first-time exercisers to be sure to rest after a day of working out is usually not a tough sell! As you build up strength, the aftermath of anaerobic exercise is less painful. You become accustomed to what your worked muscles feel like, and as you get the knack of anaerobic exercise, it's no longer a shock to your system. LESS