Tuesday, September 15, 2015

High Intensity Interval Training - Not so fast.

If you follow this blog, you know that we use high speed exercise training  (see SpeedGeezerto jumpstart the nervous system in people who are suffering from slowness (people with Parkinson's Disease and older adults).  This post is to clarify the difference between our speedwork approach and something called High Intensity Interval Training (HIIT), which is quite popular right now in the fitness industry and receiving much attention in physiological research.  I will first provide you with some information about HIIT and then return to the focus of our speed-based exercise strategy.

The American College of Sports Medicine (ACSM) provides a public brochure about HIIT here: https://www.acsm.org/docs/brochures/high-intensity-interval-training.pdf 

The following two bullets are taken directly from the brochure:
  • Definition: High intensity interval training sessions are commonly called HIIT workouts. This type of training involves repeated bouts of high intensity effort followed by varied recovery times.  The intense work periods may range from 5 seconds to 8 minutes long, and are performed at 80% to 95% of a person’s estimated maximal heart rate, the maximum number of times your heart will beat in a minute without overexerting yourself. The recovery periods may last equally as long as the work periods and are usually performed at 40% to 50% of a person’s estimated maximal heart rate. The workout continues with the alternating work and relief periods totaling 20 to 60 minutes.
  • What are the Safety Concerns with HIIT Training?  Persons who have been living rather sedentary lifestyles or periods of physical inactivity may have an increased coronary disease risk to high intensity exercise. Family history, cigarette smoking, hypertension, diabetes (or pre-diabetes), abnormal cholesterol levels and obesity will increase this risk. Medical clearance from a physician may be an appropriate safety measure for anyone with these conditions before staring HIIT or any exercise training. Prior to beginning HIIT training a person is encouraged to establish a foundational level of fitness. This foundation is sometimes referred to as a “base fitness level”. A base fitness level is consistent aerobic training (3 to 5 times a week for 20 to 60 min per session at a somewhat hard intensity) for several weeks that produces muscular adaptations, which improve oxygen transport to the muscles. Establishing appropriate exercise form and muscle strength are important before engaging in regular HIIT to reduce the risk of musculoskeletal injury. 
The members of our research team in the College of Health Sciences would love to see your functional abilities and cardiovascular health improve to the level at which you can safely practice HIIT, but high intensity exercise comes with risk factors that should be considered carefully. Our speedwork program is designed such that high speed movements are are paired with low resistance.  This means low force, light weights and low effort settings on bicycles and other equipment.  We typically set the bicycles on effort levels of "0" or "1".  We use 20-second intervals at high speeds but we watch your heart rate and blood pressure so that we can adjust the recovery time to keep your intensity in a moderate range.  If you wish to someday practice HIIT, a program like SpeedGeezer might be a sensible first step to get the nervous system going.  See the section in the ACSM brochure on HIIT called "The First Step" for more guidance.