Exercise Workouts / Category / Emile Du Toit / May 6th 2014
There are a huge amount of studies ratifying the fact that exercise delays, and in some cases even averts the onset of disease. There will always be divergent opinions on what specific type of exercise to pursue. Perhaps the more important debate, however, should be around how much exercise is optimal, and at what intensity.
High intensity interval training (HIIT) nowadays has a significant number of studies behind it demonstrating that it can efficient alternative to the traditional endurance based training. It has been shown to have similar and indeed often superior benefits to traditional endurance training in both healthy and unhealthy people.
As discussed elsewhere, there is a growing body of research demonstrating that short-duration high intensity interval training can lead to similar positive changes to moderate intensity endurance training, with a fraction of the actual exercise time or total time commitment. Traditional endurance based moderate-intensity long-duration exercise has also been shown to have some shortcomings when it comes to cardiac patients. In fact it can even be a factor in inducing heart attacks.
However, all-out intensity training like the Wingate model is also likely to be unsafe for cardiac patients.
The Wingate model has subjects performing 30 second bursts of all-out exercise against (170% of former VO2 max and 100% of peak power), followed by 4 minutes of rest. This is repeated 4-6 times. Several modified versions of short-duration HIIT have been designed, and we will take a quick look at two of the most recent ones.
This HIIT training regime was designed as an alternative to the all-out programs in order for it to be safely available to people with certain diseased conditions such as cardiac problems, Diabetes type 2 and obesity.
They extended the model to people with these types of chronic metabolic diseases by reducing the intensity and increasing the duration, but nevertheless maintaining the time efficiency. Here is a quick breakdown of their program:
This model was found to have similar efficacy to the standard short-duration HIIT model!
The Cardiovascular Prevention and Rehabilitation Centre in Montreal (ÉPIC) have researched their own model for short-duration HIIT.
They agree with Gibala et al that the Wingate model is not safe enough for chronic metabolic disorders. However, they feel that the Gibala model (80-90% maximal heart rate, 60% peak power) does not have the intensity to constitute HIIT. They are also unsure whether the safety of this model has yet been demonstrated, and feel it requires longer term testing.
The awesome thing about the Gayda model is that it has undergone long-term testing!
Their model involves 15 or 30 second bursts of 100% peak power (170% of former VO2 max), interspersed with passive recovery periods of exactly the same duration.
Relative to longer exercise bouts with less intensity (such as the Gibala model), they found that these short bursts resulted in the following:
In comparison with traditional endurance exercise this protocol was found to be not only more efficient, but also safer. Unlike endurance exercise it was found to ‘not induce significant arrhythmias or myocardial cardiac injury in stable coronary and heart failure patients’.
Over a 9 month period with obese subjects it was found to be superior to moderate intensity long duration exercise in the following in the following areas:
They concluded that 2 weekly sessions of their modified short-duration high intensity interval training program was safe for use with obese individuals.
There are similar programs that have been tailor made and validated for various other specific cardiac populations.
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