I got some excellent feedback on my cardio program video blog last week.  Thank you!  Also, I have been reading some very useful information on-line recently with people taking the “my way is better than your way” approach.

I thought I would put my thoughts on this topic on paper(so to speak), if only to clarify for everyone exactly what some of the terminology means.

Cardio-vascular training comes in many different forms.  I am going to do my best to clarify what – at times – is an emotional battle.

Traditionally when people think of cardio, they think of steady-state continuous running.  This is when the pace of the run remains essentially unchanged throughout the duration of the workout.  The pace seen during road races and marathons is an example of steady-state continuous running.

Then you have interval-based training.  This type of training as been around for over a century.  As the name implies, there are intervals, or periods of time within the workout, when the speed changes.  Often these workouts are described by defining the work period compared to the recovery period.  For example, if I am running on the street, I may increase my speed for say, the distance covered by a city block and then slow down for the next block to allow myself to recover.

The type of training getting all the attention now is high-intensity interval training or HIIT.  HIIT is simply a much more intense version of standard interval training.  The only difference is the intensity of the work period involved is much higher and usually much shorter duration than usual.

Just for the record; HIIT is a form of interval training, but not all interval training is high intensity.

While there are certainly benefits to each approach, there are also clear drawbacks.

Here is my version of the pros and cons of each:

Steady-state running:

  • Improves life expectancy versus sedentary individuals
  • Improves fat oxidation
  • Increased stroke volume (the amount of blood pushed out by the heard with each beat)
  • Increased mitochondria function (the ‘energy factory’ in each cell)
  • Improved metabolic function and multiple other benefits.

This all sounds great for endurance training doesn’t it?  Well, not entirely.  Some of these benefits disappear once mileage becomes excessive.  The cut off seems to be somewhere around over the 6 miles per day mark.  After this point runners can actually see a decrease in many health markers, including life span.

When used primarily for weight loss, the argument against endurance running becomes stronger.  While weight loss is common with a regular running program, much of the weight loss can be in the form of muscle mass loss.  If the individual is over age 40 it becomes increasingly difficult to regain this lost muscle mass.  Increased loss of muscle mass over time can have significant repercussions later in life where muscle mass is closely linked with longevity.

High-intensity interval training appears to offer all the benefits of endurance training and then some.

  • All the above benefits for steady-state running; plus
  • Faster body fat loss
  • Better muscle mass retention
  • Less time demands (fewer and shorter workouts produce similar or better results)
  • Quicker improvement in VO2 Max (the measure of our ability to use oxygen)
  • Decreased oxidative damage
  • Decreased heart damage

The major drawback of HIIT appears to be the toll it can take when used continually. By definition, these workouts are highly demanding.  Unless HIIT workouts are mixed in with periods of lower intensity training to allow the muscular-skeletal system to recover, joints can become damaged and tendons and ligaments strained.

It makes sense, no human system can operate at full intensity for long before a breakdown occurs.

Distance runners are a devoted group.  Similarly, HIIT followers are equally passionate; just visit any CrossFit location to get a feel for that atmosphere.  However, it would appear the ideal answer lies somewhere in the middle.

This is commonly referred to a “periodized” program.  This simply means alternating period of higher intensity with periods of lower volume work to maximize improvements and minimize injury and over-training.

NOTE:  HIIT does not need to revolve around running and sprinting.  High-intensity activities can come in many forms; strongman training, bodyweight movements, circuit training with weights, etc.

For example:  You may do HIIT workouts for two weeks, switch to moderate interval training for two weeks and then lower volume, steady-state work for another two weeks and then repeat the cycle.  The exact breakdown of these cycles depends upon your training goals.  The key is to never overuse any one program.

As I have stated in previous articles, we as humans were designed to sprint after dinner, then rest.  Sprint away from predators and don’t become dinner, then rest – otherwise known as “real world” interval training.  I have always made my position clear in that I feel very strongly about the benefits of sprinting versus slower running.

This goes back to a quote I read when studying Russian training articles at Boston University in which Russian sports scientists maintained, “Sprinting is the foundation of all sport.”

Recently I heard a quote taking it one step further stating, “We were meant to throw a rock at what we wanted for dinner, not chase it.”

Whichever your preference, be aware of the benefits and drawbacks, but when all is said and done – keep moving my friends.