One variable of interest in Paoli and colleagues’ study was excess postexercise oxygen consumption, or EPOC. This represents the oxygen consumption, or energy expenditure (above the baseline, or pre-exercise, level), that occurs after an exercise bout. It is sometimes called “after-burn,” implying the burning of calories after the workout.
Imagine this science fiction scenario: While preparing your client for a set of back squats, the Training Scene Investigators (TSI) interrupt with a spot check. After your client has undergone a DNA mouth swab, a quick noninvasive laser muscle biopsy and a family history interview, the agents issue a comprehensive report.
Exercise professionals devote fervent attention to learning the intricate mechanisms of muscle actions and understanding how the contractile proteins (such as myosin and actin) create force to do an array of exercises. But the source of that force—the biochemistry of energy—often remains a mystery. This column will discuss recent explanations that help demystify the processes happening at the molecular level, where cells channel energy from food into the work accomplished by exercise.
Before we can compare HIIT and continuous endurance training, it’s important to review how the body’s cardiovascular system adapts to an aerobic workout. During aerobic exercise, heart performance is based on heart rate, stroke volume (the amount of blood pumped per beat) and heart contractility (the forcefulness of each heart contraction). These variables increase blood flow and oxygen supply to meet the demands of exercising muscles.
If you haven’t had a client ask about it yet, you will soon. Intermittent fasting has hit the mainstream, and a lot of peo- ple are taking notice.
Proponents claim that intermittent fasting causes more rapid weight loss than other approaches; that it makes dieting easier; and that it improves blood glucose control and blood lipids. Does the current body of evidence support these claims? Let’s find out.
What Is Intermittent Fasting?
Long-distance running continues to attract new enthusiasts throughout the world (Tonoli et al. 2010); its unique combination of benefits can help people to control their weight, improve cardiovascular function and fend off a host of chronic health problems (van Gent et al. 2007; van Middelkoop et al. 2008). But for all these advantages, running is hard on some parts of the body, often leading to lower-extremity injuries (van Middelkoop et al. 2008).
What Are Running Injuries, and How Prevalent Are They?
High-intensity interval training is enormously popular in the fitness indus- try this year. HIIT workouts typically include short bursts (6 seconds to 4 minutes) of intense exercise (≥ 90% maximal aerobic capacity) alternating with relief breaks of varying lengths (Kessler, Sisson & Short 2012; Boutcher 2011).
The workouts include a limitless vari- ety of exercises, including