Cardio v. HIIT: HIIT Fans Stack the Deck
By Joan Kent, PhD
I use high-intensity interval training often in my own workouts and when teaching.
But when staunch advocates of HIIT compare the benefits of HIIT with standard cardio, they kinda cheat.
In the hands of the die-hard HIIT fan, the word "cardio" has become code for lame-o exercise at the lowest levels of intensity. It's no surprise that the benefits – if any – of such lame workouts would fall far short of the benefits of HIIT.
Yet no one challenges the criteria. Let's challenge them with a few simple facts.
You Can Go Hard AND Long
Intense training doesn't always have to involve short intervals of, say, 20 to 60 seconds. If you train aerobically and train seriously enough to achieve true aerobic benefits (improved tidal volume, greater blood volume, increased stroke volume, denser capillary network, greater size and number of mitochondria, more type I muscle fibers, and more fat-burning enzymes), you can maintain a high level of work for a pretty long time.
Elite marathon runners, for example, run faster than 5-minute-mile pace for 26.2 miles. Most people would find it difficult, if not impossible, to run one 5-minute mile. It's a fast pace. Elite marathoners do it for a couple of hours.
To quote Matt Fitzgerald (well-known marathoner, trainer, and author of several books and many articles), "well-trained endurance athletes really don't have to slow down much as they increase the duration of their efforts. We are not the folks reading magazines on elliptical trainers."
You Can Combine Cardio With HIIT
A training combination that appeals to me fits about 8-12 intense intervals into a long training of moderately high intensity.
It's not just my personal preference. Evolutionary evidence suggests this way of training is precisely what we were always meant to do.
In his book Born to Run, Christopher McDougall reveals the blend of morphology, paleontology, anthropology, physics, and math that led to understanding how humans became the greatest distance runners in the animal kingdom.
No way this article can do justice to McDougall's fascinating and detailed description of the emergence of homo sapiens over Neanderthals (they were parallel species), and the evolution of humans as supreme hunters hundreds of thousands of years before the creation of hunting tools (spearheads, bows and arrows).
A few of the evolutionary changes include:
• upright posture to allow deeper breathing and limit retention of sun heat.
• the ability to release body heat through sweat, rather than panting like other mammals until they must rest or die of hyperthermia.
• the ability to accelerate once the pursued animal has been run to exhaustion.
This human "persistence hunting" was a combination of endurance running primarily and short sprints. Humans evolved to run in conditions that no other animals can match, and it's easier for us.
You Can Stay Good at Endurance Long-Term
Endurance athletes can often continue into what's considered old age in other sports. In such activities as distance running, they can still out-perform teenagers or 20-year-olds until their mid-60s.
The most striking thing my then-35-year-old coach, Jim Karanas, noticed at his first double-marathon was the age of the runners, who were mostly 45 to 55. He said that told him immediately that the ultra-run was, first and foremost, a mental challenge.
But let's not limit this to running. Endurance athletes of other types display similar results. Master's cyclists in their 50s and up often outperform younger cyclists.
In his 50s, Coach Jim used to race against the cyclists in the 30-year-old category – because he could perform better against them than against the experienced cyclists his own age! The older guys kicked Jim's butt when he was first starting to race.
Coach Jim was also one of the few (and the oldest) that weekend to ride the notorious Furnace Creek 508 fast enough to qualify for RAAm, the Race Across America.
When workouts are always high-intensity, a failure to recover fully, over-training, and a high incidence of injury are likely. Also, burn-out after constant high-intensity work makes it feel like drudgery, instead of something to look forward to each day. Why not work out in a way that you'd enjoy long-term?
The choice isn't really between short, intense intervals and long, slow cardio with a magazine. The right kind of training comprises both. The cardio, of course, should be hard enough to cause a training effect, not help you catch up on your reading.
That perfect combination is effective, enjoyable, sustainable over the long haul, and entirely in sync with our evolutionary nature.
Nutrition is the #1 best way to enhance your workouts and your fitness, and I'd love to help you. Please visit www.LastResortNutrition.com and request your free Empowered Eating Consult. Discover how easy it is to make a few small shifts that produce big results.
Brought to you by Dr. Joan Kent, best-selling author of Stronger Than Sugar: 7 Simple Steps to Defeat Sugar Addiction, Lift Your Mood, and Transform Your Health.