What is the most effective form of cardio to crush calories? HIIT or steady state?
It is frightening that 61% of South Africans are overweight or obese. These shocking statistics place South Africa third on the rankings of the fattest nations in the world. Also, South Africa has the highest overweight and obesity rate in sub-Saharan Africa, with four out of 10 men carrying excessive levels of fat.These levels of body fat
These levels of body fat can increase the risk of many diseases, including diabetes, high blood pressure, stroke, heart disease, arthritis, chronic kidney disease and certain cancers, and when the fat is located around the abdomen, the risk for developing the above diseases is increased even further.
Exercise for fat loss
While many supplements, drugs, surgeries and gimmicks exist that claim to reduce body fat, the best long-term (and healthy) solutions to reduce excessive body fat remain an increase in your calorie expenditure through exercise, coupled with a decrease in calorie intake through diet.
However, this oversimplification of fat loss is compounding the problem of fat gain in many South Africans, aided by the fact that many researchers and professional athletes alike continue to claim that you “cannot out-train or out-run a bad diet”.
While it is true that you will never out-train a bad diet, it is also true that you will never achieve the physique you desire or attain the performance levels you aspire to by only eating properly. Exercise is an important element in this equation. This is because exercise not only provides numerous benefits, which no supplements, drugs, surgeries, gimmicks or fad diets can, but it also provides long-term benefits to your body composition, depending on how much fat and muscle mass you have and the type of exercise you do. The caveat to that statement though, which often gets lost in the noise, is that a higher dose of exercise is needed to reduce existing excess weight and obesity than is required to prevent weight gain or fat accumulation.
Count cardio in
Aerobic exercise in the form of walking, running, rowing, cycling or swimming provides several important benefits over diet-only weight loss and fat loss interventions.
More specifically, aerobic exercise can improve heart function; improve mental health by reducing stress, anxiety and/or depression; helps the immune system respond to mild infections, reducing the chances of contracting certain diseases; increases longevity; improves sleep quality; and it reduces fatigue. Most importantly, aerobic exercise increases cardiorespiratory function, which is a direct determinant of your ‘fitness’.
It can also be an effective tool in weight reduction and fat loss, when the correct intensity, volume and duration of training is applied. When it comes to fat loss, aerobic training can take the form of low- to moderate-intensity continuous or steady-state aerobic training, or high-intensity interval training (HIIT). But which is better?
“A higher dose of exercise is needed to reduce existing excess weight and obesity.”
Steady state aerobic training consists of exercise performed at a relatively constant speed or intensity for an extended period of time, while HIIT is exercise performed at a high speed or intensity interspersed with short rest intervals.
A common notion exists that HIIT is best for fat loss. However, there is currently a lack of scientific research about the effects of HIIT on body composition, relative to the effects of steady state aerobic exercise training.
Although steady state aerobic exercise has undoubtedly proven effective in the long-term management of weight or fat loss, many studies have indicated that HIIT may be more effective than steady state aerobic exercise in reducing body mass, trunk fat, and waist circumference in normal weight, overweight and obese adolescents and adults. In addition, the benefits gained from HIIT are especially important since the adaptations to HIIT appear with considerably less (50-60%) exercise time than required from steady state exercise, making it perfect for those with limited time to exercise.
However, HIIT may not be the best option in a real-world setting for the elderly and overweight or obese individuals, and those just starting to exercise, because of the risks associated with high exercise workloads. In addition, when it comes to fat loss and body composition in the long-term, steady-state aerobic exercise has been proven to be equally effective to HIIT at reducing body weight and body fat following aerobic exercise irrespective of intensity (as long as the intensity ranges from moderate to vigorous), with slightly more weight loss being found in those who exercise longer per week.
“HIIT places greater stresses and recovery demands on the body. This can lead to slower recovery and increased injury risk, both during and after HIIT.”
The best approach
The question then is, should you remove steady state exercise completely from your programme?
Even though it is well-known that HIIT is more effective than steady state aerobic exercise in the short-term, it is important not to discard steady state aerobic exercise completely. This is so because HIIT places greater stresses and recovery demands on the body. This can lead to slower recovery and increased injury risk, both during and after HIIT. So, by doing steady state aerobic training (along with well-planned HIIT sessions) an individual will recover faster from steady state training and be able to perform more of those sessions than HIIT.
In addition, these steady state training sessions may actually facilitate recovery from HIIT by increasing blood flow and nutrients to the muscle tissue damaged during HIIT (and other forms of training). Too much HIIT combined with additional exercise training and restrictive diets can also result in a loss of muscle mass. This is problematic because muscle mass is critical to maintaining metabolism and burn fat during the 21-23 hours when an individual is not training.
Furthermore, HIIT may also not be appropriate for beginners because HIIT may be too stressful for such an individual. In these individuals, steady state is a much better and safer option to lose fat and improve cardiorespiratory fitness for an appropriate base in anticipation of HIIT training, provided diet is correct (total calorie intake and macronutrient ratios).
Also, in many cases, if exercise is too hard, which is often the case with HIIT, individuals might avoid exercise completely. It is, therefore, better to perform steady state exercise the majority of time (when time allows) and HIIT on days when the individual is physically and mentally prepared for it.
By Brandon S. Shaw, PhD, IPAP-AT, Professor at the Department of Sport and Movement Studies, University of Johannesburg