HIIT or steady state cardio for fat loss. Which one is better? As summer teases itself in you may feel an urge to get on the exercise train.
High intensity interval training or HIIT
If you do not know what HIIT is, it is exactly how it is described. High intensity intervals are alternated with relative rest or recovery periods. It is repeated multiple times to complete a workout. It could include aerobic exercise like biking or running, and it can also include resistance training, plyometrics or body weight exercise.
In general the effort required during the high intensity phase will range from 80-100 percent of your VO2max, heart rate maximum or maximal power output. The active recovery/rest phase is usually around 50-70%.
Here is some research findings presented by Bryce Hastings a physiotherapist and a presenter at CanFitPro, where HIIT sessions were compared to vigorous steady state cardio.
The HIIT sessions required an activity level where greater than 85% of heartrate (HR) max was achieved. The HIIT subjects demonstrated a higher degree of improvement in VO2 max(cardiovascular fitness), body fat reduction, and triglyceride reduction.
The optimal aggregate amount of time spent over the course of a week in HR max should total 30-40 minutes. So for example, if you do a 30 minute HIIT workout and 15 minutes is spent in HR max, you would need to do this twice weekly to get the 30 minutes.
It was highlighted that in order to participate in this HIIT program, you really need to be in shape already. Given the high level of exertion and higher risk for injury, the above HIIT protocol would not be something for a beginner exerciser.
What if you are a beginner exerciser or recently less active?
So what if you are a beginner exerciser or recently less active? Can you still use and benefit from HIIT? I recently came across a podcast whose guest speaker was Dr. Martin Gibala, described as a world-leader in HIIT research. His perspective included HIIT for beginner’s which included cardiac rehab clients.
It would appear that the term HIIT can be used very loosely to incorporate a larger range of fitness abilities, and hence a wider range of intensities. Other terms like MIIT(moderate intensity interval training) and LIIT(low intensity interval training) are also part of this family of training protocols.
To make it simple, just start with IT(interval training). Essentially, move for a period of time, then move a little harder for a little while, then repeat. Seriously, it’s that simple. As always, if you are unsure if it is safe to exercise, follow up with your health care practitioner.
Interval walking is an example of an activity that could be performed in intervals. Simply, brisk walking could be interspersed with recovery periods at a slower pace. If you have found most of your days are spent sitting this could be a perfect place to start. The degree of effort can be self regulated as well as the distance or duration.
As always, be mindful of where you are on the are you on the exercise and physical activity spectrum. Check out this post Are you evolving as an exerciser to see where you stand on the exercise and physical activity spectrum. If you are not sure if you are ready for exercise or if it safe to exercise, look for activity readiness questionnaires online to guide you or follow up with your health care professional.
Here is some more information that compares lower to moderate intensity workouts and HIIT.
Low to moderate intensity, longer duration exercise
The following info was found in an article in 2013 by exercise physiologist, Len Kravitz called “The Physiology of Fat Loss”:
In a single exercise bout we burn the most fat when exercising at a low to moderate intensity, when oxygen consumption is between 25 to 60 % of VO2max.
EPOC or excess post exercise oxygen consumption (the number of calories you burn after exercise) is higher after HIIT than after longer duration lower intensity exercise.
Weight loss with HIIT or steady state cardio
Whether you choose to do (shorter duration) HIIT or steady state cardio (longer duration with low to moderate intensity exercise), you will contribute to your weight loss goals if everything else is kept contant.
The problem is, we are often are in a big rush to see gains. We choose a level of exercise and/or a reduction in food intake that we can’t sustain. We end up hurting ourselves or feeling rotten. Our efforts at being healthier are at risk of being thrown to the wayside before the benefits are experienced.
I would propose that your desire to increase your daily activity level be addressed independent of any weight loss goals. If you are just starting out on the fitness terrain, work on one thing at a time. Start with activity goals that you can sustain, and as always, start small. Making initial fitness goals that do not include body fat level reduction may help to keep things simple and expectations in check.
Self efficacy and exercise
Once your are on the exercise wagon, chances are you will see changes that will make fat loss goals a lot easier. Develop your exercise habit. This realization that you can succeed at an exercise program can spread into other areas of health. Like making positive food choices more often than not.
Don’t try to do a complete rewiring of all of your (not so good) habits from the outset. Just start rerouting one at a time. Before you know it, you will have transformed yourself into something you may have never imagined. Doesn’t that sound like fun? Let’s GO!!