I hope your week is off to a good start.
First things first, before we hit you with some knowledge gainZ, note
that we are currently taking on clients for coaching, so if you would like to work with either of us here at Triage, feel free to get in touch. If you'd like more information on that, or simply to read about some of our other clients, you can do so here.
Now, let's get stuck in......
We recently posted an article comparing the effect of continuous training vs high intensity interval training on fat loss. This included a discussion of the evidence related to energy expenditure, energy intake, fat loss outcomes and, importantly, adherence and
enjoyment.
A commonly held stance is that interval training simply isn't appropriate for overweight/obese individuals. While this makes
intuitive sense at face value and does have merit, it's worth taking a look at what the research has to say.
“High-intensity interval and moderate-intensity continuous training elicit similar enjoyment and adherence levels in overweight and obese adults.” (Vella, Taylor and Drummer 2017)
Now, before we discuss this study in particular, I want to point out something that I feel isn’t discussed very often, at least from what I have read. A lot of people point out the fact that overweight, untrained individuals may be far
less likely to adhere to sprint / high intensity intervals, since they are far more difficult. This is a very fair point that I agree with, to an extent, but there is another side of the coin. The same individuals may have always hated exercise. They may not want to spend much time in the gym. Therefore, a shorter, higher effort bout where there is a degree of novelty (max effort, rest, repeat etc.) and some sort of a goal (e.g. reach 500 Watts or maintain 15 km/h for 30s etc.) may actually
support adherence vs 30 minutes of the same monotonous task. So, I definitely don’t think it should be viewed as black and white.
The
authors approached this study with the intent of comparing adherence to and enjoyment of high intensity interval training vs steady state training in an unsupervised setting. This is important, as most studies are conducted in laboratories, which doesn’t really tell us much about the real world. They also investigated cardiometabolic outcomes, but that is best reserved for other articles.
Subjects: 17 sedentary, overweight/obese adults between the ages of 18-44, 7 of which were male, 10 of which were female.
Steady State Training: 20 minutes at 55-59% heart rate reserve (max heart rate – resting heart rate).
High
Intensity Intervals: 10 x 60s at 75-80% heart rate reserve, with intermittent rest periods of 60s at 35-40% heart rate reserve.
To assess exercise enjoyment, the subjects completed the Physical Activity Enjoyment Scale on the weeks 1, 4 and 8 of the 8 week study.
Results
Adherence in both groups was ~93%, which lines up with what would
be expected in laboratory based studies, as the authors point out. But most interestingly, as is clear from the graph, enjoyment was very similar across the 8 weeks. This is an interesting and novel finding, as it suggests that, contrary to the general rhetoric, HIIT is a viable option for both enjoyment and adherence, even in sedentary, overweight/obese individuals.
Now, what you do also have to be aware of is that there is a lot of variation in the types of protocols used in these studies. For example, this study used a 60s on 60s off approach and classified it as high intensity
interval training, whereas some people will refer to sprint intervals as being the same, and some studies (like the EPOC study) will refer to intervals as long as 4 minutes as high intensity interval training. There’s a lot of variation, which is important to be aware of when looking at studies or trusting the advice people share, but not that important for your own practical understanding.
I hope that sheds some light on a topic that gets a lot of lip-service, as it's important that we do actually look to see how it plays out in research.
Kind Regards,
Gary & Paddy
Triage Method
