Time to Sprint

High levels of fitness as a teen protect against later cardiovascular disease, longer is better in sprint interval training and your weekly recommendations.

The Rundown

Teen Fitness & Later Heart Disease. A paper published in the British Journal of Sports Medicine says that male adolescents with the highest levels of physical fitness were 33 percent less likely to have severe narrowing of the coronary arteries almost 40 years later compared to their least-fit counterparts.

The study’s authors analyzed data on close to 9,000 male adolescents, most of whom were Swedish military conscripts, collected when they were around 18 years old and again about 40 years later. The subjects were initially assessed for cardiovascular fitness and tested for upper-leg strength.

When the adolescents reached middle age, they were tested for the amount of plaque in their coronary arteries using a noninvasive technique.

The researchers acknowledge that the study does not explain how fitness influences the risk of cardiovascular disease in women (as Swedish military conscription was mandatory only for men before 2010), but the findings do suggest that high levels of physical fitness as a (male) adolescent may offer strong protection against coronary artery disease later in life.

Time to Sprint. A recent study out of Waseda University, Japan examined the connections among different parts of sprint interval training, including duration and repetitions, and the body’s physiological responses. The findings suggest that longer is better when it comes to oxidative metabolism.

The team analyzed two different sprint interval exercises: two 20-second sprints with a 160-second recovery and four 10-second sprints with an 80-second recovery.

To examine the influence of the intervals on physiological and metabolic responses, the team looked at VO2 levels and changes in tissue oxygenation index in thigh muscles. They also utilized the T2-weighted MRI to assess the activation of thigh muscles.

While both the protocols significantly increased whole-body and peripheral oxidative metabolism and the activation of major thigh muscles, the 20-second sprints outperformed the 10-second sprints when it came to greater peripheral oxidative metabolism.

A lead author of the paper comments on its real-life applications, “Lack of time is a major hindrance to regular physical activity. However, the exercise modalities employed in our study require less than 15 minutes to complete and provide considerable health benefits.”

Extra Point

Watch

Open Heart. This Netflix documentary follows New York Rangers goalie Henrik Lundqvist’s struggles to return to hockey after having major heart surgery. One reviewer called it “a fitting epilogue to an outstanding life in the NHL.” Open Heart is streaming now.

Listen

Science Vs. This podcast describes itself as “your team of friendly fact checkers that blow up your firmly held opinions and replace them with science.” While it’s not specifically a fitness or sports-themed podcast, the episodes cover a variety of topics with some that intersect with fitness culture, including intermittent fasting, sleep and caffeine consumption.

Read

What to Eat Before and After Your Workout. Journalist Matt Fuchs talks to exercise and nutrition experts who offer suggestions on how to fuel your body pre and post training in this article for Time magazine.