"Exercising by doing interval training not weight lifting could be the secret to staying young according to a new study http published Tuesday in the medical journal Cell Metabolism.  Highintensity aerobic interval trainingor exercising in bursts of moderate and highintensity running cycling or other aerobic activitymay help to reduce the effects of aging at a cellular level researchers found.  GMA Live Stream Workout Julianne Houghs Favorite Cardio Dance Routine httpabcnews.go.comHealthgmalivestreamworkoutjuliannehoughsfavoritecardiostoryid Reporters notebook My  hours locked inside a metabolic chamber httpabcnews.go.comHealthreportersnotebookhourslockedinsidemetabolicchamberstoryid Scientists analyzed three groups of people who were exercising by doing highintensity aerobic interval training resistance training or a combination of the two over the course of a week period.  While scientists found that all three types of exercise improved participants lean body mass at a cellular level they found that the group participating in the high intensity interval training also saw improvements in the exercise capacity of their muscles mitochondria. As people age their mitochondria which are responsible for producing energy for your cells become less efficient.  High intensity interval training essentially reversed many agerelated differences in aspects of elderly participants mitochondria the researchers wrote in the studys summary.  Dr. Richard Besser ABC News chief health and medical editor called the studys findings very interesting.  When they looked at the cellular level the changes they saw in the older peoples cells with the highintensity training made those cells look more like younger peoples cells in terms of how they handled energy Besser said today on Good Morning America httpgma.yahoo.com. That was very interesting.  Chris Powell trainer and transformation specialist on ABCs Extreme Weight Loss said the term highintensity interval training can be terrifying to people but it should not be.  High intensity interval training is just aerobic training with short bouts of weight training in between Powell said today on GMA. The beauty of it though is that we get to control the throttle of our own workouts.  He continued It doesnt matter if youre an elite athlete or you havent moved for  years...Its all about completing not competing.  Besser advised people to consult with their medical doctor before beginning any new exercise regimen including highintensity interval training.  This training also known as HIIT can be done using just your own body weight and with minimal to no equipment according to Powell.  Aerobic training can be accomplished by jump roping running in place or doing jumping jacks or high knees the trainer said. Weight training can be done with exercises such as push ups lunges and back squats.  Powell demonstrated a HIIT workout of  high knees combined with  back lunges.  Its that simple he said. Theres a million different combinations. You can do it so many different ways."