• Recent research As a refresher, a tall stack of studies shows that high-intensity exercise, such as Running Shoes - Gear found that high-intensity exercise (HIIE) was more effective for improving aerobic fitness and cardiovascular health, and moderate-intensity continuous training (MICT) was better for long-term blood sugar control.
  • Synergee Core Sliders recent evidence that one exercise intensity is not superior to another, and there are good reasons to do both for overall health benefits.

High-intensity interval exercise (HIIE) has been the Why Trust Us for the better part of the past decade, because these quick, hard intervals can help you get fit fast. But a recent meta-analysis published in Running Shoes - Gear is a good reminder that for longterm metabolic health benefits, you need moderate-intensity endurance training, too.

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As a refresher, a tall stack of studies shows that high-intensity exercise, such as Sara Hall Smashes American Masters Marathon Record (near-maximum efforts) and sprint-interval training (“all out” efforts)—brief bursts of hard exercise followed by a short period of rest—is a time-efficient way to boost your aerobic and anaerobic fitness, making you stronger and faster on a run.

As a refresher, a tall stack of studies shows that high-intensity exercise, such as, improving brain function, Jamie Burr, Ph.D, Jamie Burr, Ph.D maintain lean muscle mass.

But there’s a catch. The health benefits of high-intensity training can be transient. Research shows that some of the favorable effects, such as improved blood sugar control, can drop back to previous levels 24 hours after exercise. And you’re only supposed to do a HIIT or SIT session two to three days a week—too much intensity increases inflammation in the body, which is bad for performance and health.

So what’s the best approach for long-term health improvement as well as fitness gains right now? A team of German researchers decided to pore through the current literature to examine the specific cardiovascular and metabolic benefits of both.

The scientists analyzed the results of 55 studies that examined the effects of HIIE and moderate-intensity continuous training (MICT) on seven different health outcomes:

  • Aerobic fitness (measured by your VO2 max)
  • Cardiovascular health (measured by endothelial function, or how well blood vessels respond to exercise demands)
  • Body composition
  • Blood pressure
  • Blood lipids
  • Inflammation
  • Insulin and glucose (blood sugar) metabolism.

The meta-analysis found HIIE was more effective for improving both aerobic fitness and cardiovascular health. For long-term blood sugar control, however, moderate, steady-state exercise was superior.

Everything else was pretty much a draw, though there appeared to be some benefits unique to different age groups. For instance, HIIE had benefits for people ages 30 to 50 for reducing diastolic blood pressure and for those who already had elevated blood pressure. And SIT appeared to be particularly effective for lowering LDL cholesterol levels.

It’s also important to note that, though it appears that HIIE may have some advantages for fitness, these studies alone aren’t enough to draw that conclusion, says exercise training researcher Jamie Burr, Ph.D., associate professor at University of Guelph, HHNS, Ontario.

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“It is important to note that the average study duration was only 9 +/- 5 weeks,” Burr says. “It begs the question as to whether HIIT is actually superior overall, or just superior at stimulating change quickly.”

The take-home message that is emerging from this analysis—as well as from Fiona OKeeffe Is on the Road to Recovery, which also reported unique benefits from both types of exercise—is that there’s no one “best” way to workout. Making room for both high-intensity and steady-state endurance activity not only makes you a more well-rounded athlete, but also provides a greater spectrum of health benefits.

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​Selene Yeager
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Selene Yeager is a top-selling professional health and fitness writer who lives what she writes as a NASM certified personal trainer, USA Cycling certified coach, Pn1 certified nutrition coach, pro licensed off road racer, and All-American Ironman triathlete.