Steady State Cardio Vs High Intensity Interval Training

Walking, swimming, cycling, and the cross trainer are all great ways to improve cardiovascular health, burn belly fat, and reduce likelihood of CVD (cardiovascular disease). Problems arise when fat loss slows after the first month or two and weight remains constant. Why does this occur, the work is still being done but the body feels almost stuck at a certain weight? These and many more questions will be answered shortly. But first, why is cardiovascular or aerobic exercise so good for you?

Steady sate cardio gained its popularity as scientists discovered the “fat burning zone anywhere between 55-65% of max heart rate” This is where fats are preferentially used for aerobic metabolism. After these studies were published it was recommend that fats will be burnt preferentially over muscle glycogen during these exercises. Although this is true, they did not consider the overall amount of energy used, and such low intensity exercise would have to be performed for much longer duration to burn the same calories compared to a higher intensity exercise.

The body is highly adaptable and will become efficient quickly once a stimulus is applied (walking on a treadmill). An obese individual may find walking on the treadmill works very efficiently at burning fat during their first 3 months. But as the cardiovascular system gets stronger, and the body becomes more efficient weight loss will slow. A new stimulus must be applied for progress to continue. This diminishing return in fat loss can lead to termination of the fitness program. While the initial gains seemed easy to achieve, they become harder and harder as we progress. With a little manipulation of the the training program, not to mention diet, the fat loss can continue.

Steady state exercise is not be the best exercise for continued fat loss but definitely plays a role in weight maintenance. A mixture of high intensity interval training (H.I.I.T), resistance training and steady state cardio will ensure continuous fat will be burnt in conjuncture with a meal plan. Being in a caloric deficit is necessary for fat loss as mentioned in my other blogs; “Belly fat, what is it, and why is it so hard to burn?” and "The 5 best types of exercise for burning belly fat". Applying progressive overload to all forms of training is essential is for continued fat loss and improvements in your body. Here are some ways to apply it to steady state cardio and H.I.I.T;

• Increase the duration; this is the easiest as we can keep the intensity the same but will eat up all of your time

• Increase the intensity, simply increasing the resistance on the bike, or the incline/speed on the treadmill to make you start walking uphill/faster can be great ways to keep the body guessing.

• Change the type of exercise from bike to elliptical to rower. A new exercise will keep the body from becoming efficient at only one form of steady state exercise.

• Build in short intense intervals into your steady state, slowly progressing towards a H.I.I.T workout, for example 10 mins easy walk, 5 mins hard walk uphill, for 45 min total.

• Continually ask yourself the question, “Is this workout challenging?” as getting comfortable at a level of fitness will stop any further fat burning in its tracks.

Let's not forget the other benefits steady state cardio provides. Decreased blood pressure, and decreased bad cholesterol (thereby reducing risk of heart disease), greater insulin sensitivity (although weights provides a greater benefit comparatively), improved endurance, improved mood, and reduced anxiety and stress. Amazing how much as little as 20-30m, 3-4 times per week can provide such substantial benefits. So even though you may not be at your final body weight goal, don’t forget how far you’ve come, and only small changes will be needed to continue to progress towards your goal.

High intensity interval training can provide the stimulus for further adaptation to occur once steady state cardio has plateaued. Increasing the intensity to a shorter burst of exercise at a much higher rating of perceived effort will provide not only cardiovascular benefits but anaerobic adaptations as well. And this extra effort will translate into greater fat loss (and overall energy expenditure) than steady state. The extra intensity will translate into an excess amount of oxygen consumption (EPOC) post workout to recover, ie heavy breathing, which has been shown to increase fat metabolism for hours after the workout has finished, whereas the fat burning returns to baseline following a aerobic workout. So the benefits of H.I.I.T are not only greater for your health but also provide a platform for continued fat loss.

The drawbacks of H.I.I.T can be the greater level of effort required, and higher starting base level of fitness, which also comes with greater injury risk. For instance, it would be unwise for a client who has never exercised before to begin a H.I.I.T workout straight away. A base level of cardiovascular endurance should be achieved prior to beginning a H.I.I.T regime. A good rule of thumb is once you can perform aerobic exercise for 40-45m continuously at 60-65% of max heart rate, you can then try some H.I.I.T workouts. So it may take a number of months depending on your initial fitness level. The higher level of effort may also lead to an increased risk of injury, so it is always important to listen to your body, warm up and cool down adequately, and get enough sleep/recovery to keep your body fresh.

In terms of your overall health, there is no right or wrong way to go about training. You need to find something that works for you and fits in with your life. But a combination of aerobic and H.I.I.T training will provide amazing results for fat loss, reduced risk of many diseases associated with a sedentary life, and mental health benefits. Be patient, train at your level, and slowly build up your engine and watch the amazing changes you are capable of!