I’d HIIT That
Happy belated July 4th weekend, I hope it was safe and enjoyable for all!
Over the weekend, most Americans took part in the most exciting part of the holiday: eating and drinking. Here we are, two days later, still feeling the effects of the alcohol, the chips and dip, and the barbeque. However, don’t feel guilty! A healthy lifestyle is just that… one that allows you to enjoy yourself with friends and family without guilt to follow.
Now, you might be looking for a way to work off all of the calories that you consumed this weekend and kick your butt into high gear for the last couple months of summer (where does time go!? It’s already July…)
Whether you have heard about the new trend, or maybe you already incorporate it into your workouts, I am going to differentiate high intensity versus low intensity workouts and which you should be focusing on.
The myth that was previously believed by researchers, and still followed by many, that cardio is the best way to change your body, whether it is losing body fat or gaining muscle… or both… False!
As new research has been done, studies have found that weight lifting is a much better way to lower body fat and change your body composition. However, cardio is still a very important aspect. Rather than doing hours of cardio, hoping to see great results, new information is coming out about high intensity interval training (HIIT) vs. low intensity steady state cardio (LISS).
First and foremost, is it important to differentiate between losing fat and losing weight. Losing fat is often times done by following a precise nutrition plan and following an exercise routine that promotes fat burn while maintaining muscle mass. On the other hand, losing weight occurs when more calories are burned than are consumed and can occur due to the loss of muscle, water or fat, or a combination of the three. It is up to the individual and a certified health professional to develop an adequate plan to meet their individual needs.
What exactly is HIIT & LISS?
High intensity interval training consists of short sprint intervals at maximum capacity, followed by low intensity work or a rest period. For example, sprinting for 30 seconds, followed by 30-minute rest period or light jog.
On the other hand, low intensity steady state cardio consists of low-moderate intensity exercise (usually around 60%-70% of max capacity) for a longer period of time, for example walking on the treadmill.
Without going into the deep details of how your body works under either situation, it is important to understand the benefits of both types of cardio and how you should be incorporating each into your routine.
In simple terms, over time your metabolism adjusts to your body’s average expenditure and needs. In order to change your metabolism, to facilitate fat loss, one must increase their muscle mass and number of mitochondria in your muscles. The mitochondria produce energy in the form of ATP and burn fat. The more mitochondria that one has, the more active they are and they have a greater capacity for fat loss. HIIT exercise actually increases the capacity of the mitochondria as well as the amount of mitochondria.
Due to this, studies have shown that greater fat loss will occur with high intensity training because of this capacity. However, with LISS the calories are being burned during the exercise but there is no boost in metabolism, which prolongs the calorie expenditure. Over time, with LISS exercise your body adjusts to it and in the long run, you end up needing to do more cardio, for longer periods of time to lose fat. It is important to note that for individuals looking to maintain muscle mass, it is not recommended to run more than 45 minutes as it could lead to catabolism, or the breakdown of muscle.
A study conducted by Wilson from the University of Tampa, FL, shows that when LISS is added to an exercise routine, there is a temporary boost in weight loss but this eventually plateaus after just a couple weeks. That is because their metabolism and set point (reference point around which the body tries to keep a stable weight) were adjusted.
A great visual to determine the effects of HIIT vs. LISS would be to compare the body of a marathon runner, running at a steady pace for a long period of time versus a track runner, running short distances at a very fast speed.
It is apparent that the long distance runner is skinnier, and leaner in terms of their muscle mass. LISS actually causes more muscle loss than HIIT does because during LISS, you are not activating muscles in the same way. HIIT is simply overloading the muscle and activating muscle fibers, which in turn aids in muscle growth. Unfortunately, LISS cannot stimulate the muscle fibers in the same way, due to the nature of the exercise.
Now, despite the facts that seem to state that HIIT is more beneficial than LISS, both are actually very important to incorporate an exercise routine. HIIT cannot be preformed more than about 2-3 times per week, simply because it puts stress on the body and joints and could lead to injury. LISS can be performed a couple times per week, in a cyclical or rotational fashion to promote the most muscle growth and fat loss. LISS exercise is great for improving cardiovascular health and your body recovers faster.
As for which one is better: it all depends on what you are looking to improve on and change. Both have their benefits, as well as their disadvantages but an optimal exercise routine would have a balance of both to produce the fat burning benefits of HIIT as well as the increased cardiovascular health of LISS.
Along with following a routine of weight training, HIIT and LISS, nutrition is also a very important aspect to gain muscle and lose fat, which is another post in itself. Cardio remains a very important aspect to achieving ones goals. It is always important to consult with a certified health professional before starting an exercise or diet.