It’s a word that fills some with dread, to others, it’s simply a tool, and there are of course those who genuinely do love it.
Cardiovascular exercise, or cardio, has been the topic of discussion in the fitness industry for years now, with many researchers giving their own opinion on the most useful, effective, and efficient types of training. Recently, there has been a total boom in the popularity of HIIT, you can’t scroll through Instagram or read a fitness blog without encountering the new-cardio based fad.
HIIT seems to be sold as a new, magical discovery, appearing to promise a calorie burn of 1000’s in a very short space of time.
Is HIIT the miracle alternative to slugging away on the treadmill we’ve all been hoping for?
But does it have its proven benefits?
I want to discuss two types of cardio in this blog. HIIT and LISS.
LISS stands for Low Intensity Steady State Cardio, which is basically what we think of when someone mentions cardio. It’s the typical lengthy sessions of exercise that could last anywhere between 20 minutes to an hour (or even more), where you engage in a low level of sustained physical activity, such as cycling or running. It isn’t too hard on the lungs and heart- someone performing LISS should be panting slightly but should still be able to hold a conversation, sitting comfortably between 50%-60% of their maximum heart rate (max heart rate can be easily calculated as 220 minus your current age). It should be challenging yet sustainable. As a very rough number, a 60 minute LISS session on the stairmaster will burn 400-500 calories per hour (of course this will change based on height, weight, ability etc.)
HIIT stands for High Intensity Interval Training, and is the name for a new form of cardio which requires 15-25 seconds of maximum, all-out bursts of effort followed by a rest or low intensity interval for recovery. This process is then repeated 6 to 10 times. It can take many forms: burpees, ropes, climbers, rowing, med balls or even hitting the treadmill, as long as you are working to your absolute maximum. Working at this higher level will burn more calories in a shorter space of time, and will also kick start the ‘calorie after-burn’ we often hear about with HIIT workouts.
Essentially, when you finish a HIIT session you will have created such a deficit in your body’s oxygen that it will have to work harder to return all its levels to its resting state. This boosts your metabolism and means you’ll continue to burn more calories up to 24 hours after the session, depending on the individual and how hard you’ve worked of course. The name for this is EPOC (Excess Post-exercise Oxygen Consumption), but this state will only kick in if you’ve really worked for it. If you aren’t desperate for that rest interval in the routine then you are not working nearly hard enough in the high-intensity phase. A common misconception with HIIT is that you will burn the same amount of calories in 20 minutes that you might do performing an hour of LISS on a bike. This is not true. You wont burn as many in that short period, what you are counting on is creating the EPOC (afterburn) affect. There is a lot of debate amongst researchers as to how many calories the afterburn effect will actually consume. Originally it was claimed that after a session you’d be burning 400 extra calories, but newer research has indicated could really be as little as 50.
While HIIT seems to be the new craze with all its promises, it isn’t right for everyone; there are pros and cons to both types of cardio. HIIT does seem to be the saviour of time, but it does come with its setbacks too as there are more areas to consider aside from efficiency.
HIIT vs LISS
At the end of the day, as always, it’s personal preference.
With a lot of people I meet I find that they can’t justify a HIIT workout. The promise of an afterburn of calories isn’t enough to put the body under so much stress, nor do they want to factor it in in the place of a weight training session, whereas LISS can be worked in around your plan.
There are those that swear by HITT, who love to test themselves and go to their limits, but mostly I find that if your body and mind isn’t ready for it, you’ll probably be doing more damage than good.
If you want to hear more about the benefits of cardio in a workout plan, or would like my advice on which might suit you, feel free to get in touch!