"The groundwork of all happiness is health." - Leigh Hunt

High-intensity exercise and your heart

The transient effects of vigorous exercise could also be secure for some—but not all—older adults.

A fitness trend called high-intensity interval training (HIIT) continues to be going strong in gyms and online exercise classes. HIIT features short bursts of high-intensity exercise (often lasting one to 4 minutes) interspersed with periods of low-intensity activity or rest. But is it a very good idea for everybody? Not required.

Increasingly, cardiac rehabilitation programs (which help people get well from heart attacks and related conditions) are using adapted versions of HIIT. But these closely monitored sessions begin with an exercise stress test to ensure people don't have symptoms like chest pain, which may make strenuous exercise dangerous. Outside of such settings, HIIT could also be unsafe for individuals who have or are in danger for heart disease.

One of the biggest randomized controlled trials of HIIT, published last yr. BMJ Open, suggests that healthy people of their 70s can do these exercises with little risk. But by way of longevity, moderate intensity exercise appears to be just nearly as good.

A faster path to wellness

One of the most important advantages of HIIT is that you could increase your cardiovascular fitness faster by going harder somewhat than longer. Some small, short-term studies indicate that HIIT exercise can produce equal or greater improvements in blood pressure and blood sugar than moderate exercise. But since the duration and intensity of the interventions in these studies varied (as did the participants' ages and fitness levels), it's hard to generalize in regards to the advantages, Dr. Lee says.

gave BMJ Open The study involved 1,567 healthy, lively Norwegians with a mean age of 73 years. About half (the control group) were assigned to exercise for half-hour on most days. The rest received the identical instructions, but half were assigned to switch two weekly exercise sessions with a HIIT workout. The other half switched to twice-weekly moderate-intensity continuous training (see “A tale of two workouts”).

A tale of two sports

Researchers compared the 2 exercise strategies in healthy adults aged 70 to 77 during a five-year study in Norway (see essential text for more details and results).

Moderate intensity continuous training exercise consisted of exercise for 50 minutes. Participants' goal heart rate was 70% of their predicted maximum heart rate.

The “4×4” HIIT workout, which lasted 43 minutes, followed this pattern:

1. 10-minute warm-up (brisk walking or jogging) at 60% of maximum heart rate

2. Four minutes of brisk exercise at 85% to 95% of maximum heart rate

3. Three minutes of low-intensity exercise (jogging or brisk walking) at 60% of maximum heart rate

4. Repeat steps 2 and three thrice, for a complete of 4 cycles.

5. Five minute cool down.

Note: To estimate your maximum heart rate, subtract your age from 220. For 60%, multiply by 0.6. For 85%, multiply by 0.85, etc. For example, the utmost heart rate for a 75-year-old can be 220 – 75 = 145; 60% of that might be 145 × 0.6 = 87.

Similar survival rates

During the five-year follow-up, only three people within the study had adversarial events (slip injuries while exercising outdoors). There was no difference in survival between the three groups, although deaths were barely lower within the HIIT group. One possible explanation for the difference in results: People within the control group exercised greater than expected (including performing some high-intensity exercise), and only about half of the HIIT group actually did regular high-intensity exercise. In addition, those that agreed to take part in the study were more lively than the overall population, and their mortality rate was half that expected in the overall population of the identical age.

Take-home message: If you're cleared by your doctor, go ahead and take a look at adding some high-intensity sessions to your exercise routine, whether it's jogging, cycling, swimming, or other aerobic exercise. But if that extra effort and sweat seems daunting, don't worry you're missing out. “If doing HIIT fits into your lifestyle, go for it,” says Dr. Lee.

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