I often get asked what type of exercise my patients should undertake, especially as most patients that I do see are fairly active, but become frustrated as they don't get to see proportionate results after putting in a decent amount of 'work' at the gym. The classical scenario is the PT instructing you to do endless sets of crunches to get rid of lower abs fat.
Doing crunches will certainly build your abs, but if you have a few kilos of fat hiding the abs then these will not be visible. It is thus imperative to get rid of this first and this means lowering your overall body fat percentage.
There have been many theories on what exercise provides the best 'fat-busting' results and there has been a significant shift in trains of thought.
Much of the scientific evidence now points to a combination of intermediate length aerobic exercise and high intensity interval training
(HIIT).
Many personal trainers will promote doing 'cardio' to extremes to get rid of stubborn pockets of fat. This is largely a myth.
The long traditional aerobic workouts have less impact on fat metabolism and also on maximal oxygen consumption (VO2 max) compared to
HIIT. High intensity interval training has been shown to burn fat more effectively. Partly this has to do with improving glucose tolerance and lowering insulin resistance. Compare endurance runners and 100m sprinters - the sprinters tend to have a better muscular physique.
HIIT increases the resting metabolic rate (RMR) for the following 24 hours due to
excess post-exercise oxygen consumption (EPOC). After intense sessions of exercise the body goes into a state of oxygen 'deficit'. To replenish this lack and return the body back to a resting state there is an increased state of oxygen intake. Various processes take place: hormone balancing, replenishment of fuel stores, cellular repair (esp. muscle), innervation and anabolism (muscle buildup). This repair cycle is accompanied by an elevated consumption of energy. Fat stores are thus released and broken down to release fuel stores. One study result found a greater loss in subcutaneous fat.
Examples of HIIT:
- 2minutes of gentle pedaling followed by 20 seconds of intense rapid bursts at maximal effort for three sets
- 20 seconds of ultra-intense exercise followed by 10 seconds of rest, repeated continuously for 4 minutes (8 cycles)
There are numerous regimens around (
Peter Coe regimen, Tabata regimen, Gibala regimen, Timmons regimen) and its best to choose one that incorporates the exercise you prefer.
So, extended sessions of cardio are useful, however, combined with
HIIT one can achieve better results in a shorter space of time over fewer days a week, leaving you with more time to socialise and see family.
