High Intensity Interval Training (HIIT) is a super-efficient workout. Most people aren’t used to pushing into the anaerobic zone (this happens when you can’t breathe and you feel like your heart is trying to jump out of your chest). During HIIT, you work very hard in short intervals and then you recover.
You burn more calories during a HIIT workout, more muscle is preserved, and also HIIT stimulates production of your human growth hormone (HGH) by up to 450 percent during the 24 hours after you finish your workout. HGH is responsible for increased caloric burn and slows down the aging process. Calories burned from HIIT come from a higher metabolism, which lasts for hours after exercise.
Overall, HIIT produces many of the same health benefits as other forms of exercise such as reducing inflammation in your body, improving heart health, lower body fat, heart rate, and blood pressure, in a shorter amount of time. Intense exertion kicks your body’s repair cycle into hyperdrive and as a consequence you burn more fat and calories in the 24 hours after a HIIT workout than you do after a steady-pace workout such as running.
A study recently published on cell.com shows that HIIT is more effective than weight training or cardio for improving metabolic health, is superior for fighting age related decline, and may yield anti-aging benefits down to the cellular level. HIIT was found to be even more effective at improving mitochondria biogenesis.
All cells in our bodies contain mitochondria. They produce energy that powers everything your cells do. HIIT boosted the ability of the mitochondria within cells to generate energy by 69 percent in older volunteers, and by 49 percent in the younger group. Mitochondrial activity declines with age, which may aggravate fatigue and reduce the size and ability of muscles to burn excess blood sugar – a risk factor for diabetes. But this decline was halted and even reversed with HIIT after three months of interval training in older participants in the study, where everything converged towards what they saw in young people. Interval trainers also saw surges in the amount of oxygen they could inhale and consume, another indicator of higher metabolism.
New research also found evidence of the HIIT effect on the aging process by measuring the structures at the end of chromosomes, known as telomeres. Telomeres are a kind of “junk DNA”, which does not encode protein sequences and whose function is not well known. Each time a cell divides, the telomeres get shorter. When they get too short, the cell can no longer divide; it becomes inactive or “senescent” or it dies. This shortening process is associated with aging, cancer, and a higher risk of death.
We know that our telomeres start to shrink as we age, but we also know that older people with longer telomeres don’t experience vascular aging as rapidly as people with shorter ones. This means their veins are generally in better shape and they are less at risk for conditions like heart disease and stroke. Researchers found that the people in the aerobic and HIIT groups experienced more telomerase activity. Telomerase is an enzyme that adds nucleotides (the molecules that form DNA) to telomeres. This process causes chromosomes to become longer. In other words, HIIT acts “like a drug” protecting your telomeres, producing the anti-aging effect.
Gabriela Brochu, Biologist, Ph.D.
Gabriela Brochu is a College Professor by day and Group Fitness Instructor at Saint Mary’s Fitness Center by night. She teaches HIIT a couple of times per week. Her classes can be found under the class schedule on our website: www.saintmarysfitness.com