Why high-intensity exercises are as beneficial as longer workout sessions

If you can’t spare a lot of time to exercise, you can just opt for a few minutes of high-intensity interval or sprinting exercise, says a new study.
Got no time for exercising? Well, a few minutes of high-intensity interval or sprinting exercise may be as effective as much longer workout sessions, as per a new study. Mitochondria, the energy centres of the cells, are essential for good health. Previous research has found that exercise creates new mitochondria and improves the function of existing ones. Altered mitochondrial function in response to a single session of exercise generates signals that may lead to beneficial changes in the cells, lowering the risk for chronic disease.
High-intensity interval exercise consists of short bursts of high-intensity aerobic exercise physical activity that raises the heart rate alternating with brief recovery periods. Whether the intensity of a workout affects mitochondrial response is unclear. The research team measured the amount of energy the volunteers spent on each workout and compared mitochondrial changes in the participants’ thigh muscles before and after each exercise session.
The researchers found that levels of hydrogen peroxide — a type of molecule involved in cell signalling called “reactive oxygen species” that contains oxygen and hydrogen — in different parts of the mitochondria change after exercise. While too much reactive oxygen species can be damaging to the cells, the researchers noted that the volunteers’ levels were an appropriate amount to potentially promote cell responses that benefit metabolic function rather than cause damage.
In addition, the research team found that fewer minutes of higher-intensity exercise produced similar mitochondrial responses compared to a longer moderate-intensity activity. They wrote, “A total of only two minutes of sprint interval exercise was sufficient to elicit similar responses as 30 minutes of continuous moderate-intensity aerobic exercise.”
The full findings are present in the American Journal of Physiology-Regulatory, Int. & Comparative Physiology.