How long should a cardio session last

How many HIIT (High Intensity Interval Training) schedules can / should I do per week?

The Marathon Myth: High Intensity Interval Training (HIIT) vs. Long Duration Training (LDT) I've written several FitBit articles this year describing the effectiveness of high intensity interval training (HIIT training). HIIT has been shown to develop much higher levels of cardiovascular fitness in much shorter periods of time than traditional LDT. Not only have numerous universities reported on research conducted by some of the best cardiologists and exercise physiologists in the country, but we also have champion endurance athletes around the world who use HIIT to break all existing racing records.

Recent studies now show that the retention rates for HIIT are significantly higher than for LDT. Previous research had shown that retention decreased with increasing intensity. This research failed to take into account that HIIT inherently requires much shorter periods of time.

For fitness training, the HIIT duration is usually 15 to 20 minutes, while the typical LDT workout is 60 to 90 minutes. The HIIT frequency is usually 2-3 days / week while the LDT frequency is 6-7 days / week. This significant decrease in both duration (time) and frequency (number of training sessions / week) appears to be the main reason for increased retention rates and exercise adherence.

The only big question on all personal trainers' minds should be, "Great, but what about SAFETY?" Remember that rule # 1 for any IFPA certified personal trainer, medical fitness specialist or any of our other certified professionals who are certified in one or more of the 70+ other IFPA certifications is DO NO HARM!

This is probably the most significant and controversial of all the HIIT vs. LDT news: HIIT is actually safer than LDT! Read it again! HIIT has been shown to be safer than LDT!

This is contrary to many current beliefs and is contrary to what has been considered "common sense". High intensity MUST represent a higher risk than low to medium intensity, long duration training, but again "common sense" and long-held beliefs were proven WRONG.

With the risk of sounding like that bad old grin that stole Christmas from all hard core marathon runners and endurance athletes, I have to give you conclusive research that shows that HIIT is actually safer than LDT

According to Dr. Eric Larose, an exercise and cardio health expert at the University of Loval in Quebec City, "exercise reduces cardiovascular risk by a factor of three, but vigorous exercise like running a marathon increases cardiovascular risk by a factor of seven."

Dr. Larose's study shows that marathon runners experience temporary heart damage from the exertion of running such a long distance. The further you run, the more stress you put on your body.

According to Dr. Arthur Siege, director of internal medicine at McLean Hospital at Harvard in Belmont, Massachusetts, "your body doesn't know whether you've run a marathon or been hit by a truck." I ran the Boston Marathon. When you run a marathon, your body goes into survival mode. That releases a chemical cascade within you. Your adrenal glands release stress hormones like cortisol and vasopressin. Your muscles release a protein called cytokines that causes your liver to make C-reactive protein. This triggers an inflammatory response to protect you from all the chaos in your body. This can lead to cardiac arrest, which is not uncommon in such long races. As you dive deeper into the 26.2 mile race, your muscles take the brunt of the stress, and that includes your heart.

Dr. Siege and colleagues conducted a study of cardiology in the American Journal. They analyzed the blood of marathon runners less than 24 hours after the race. The runners showed high levels of inflammation and coagulation markers associated with heart attacks.

Even more troubling is another study in the American Heart Association Journal: Circulation, which found abnormalities in how blood was pumped to the heart after running a marathon, including some runners who had difficulty refilling the ventricles.

There is a lot of research and study going on on both HIIT and LDT and I will keep reporting on that. Some very passionate marathon runners offer numerous explanations for the deaths associated with LDT, including: (1) undiagnosed congenital heart defects, (2) electrolyte imbalances, (3) too little or too much hydration, (4) exhaustion of the heart in high heat / high heat humidity situations, (5) statistically low death rates, and more.

Regardless of the defense of the mind in the face of these facts, there is a relatively simple solution to the problem. Try the HIIT protocols following all of the principles of exercise science learned in the IFPA Personal Fitness Trainer or group fitness instructor certification courses.