HIIT (high-intensity interval training) is still all the rage in fitness. As the research around it kept building, more fitness professionals not only started utilizing HIIT but preached its superiority over all other cardiovascular exercise. Why waste hours toiling away on the treadmill when you can get the same results in the matter of minutes? This led to widespread use of HIIT with numerous exercises. Instead of being utilized on a treadmill or bike, it began to be implemented with any and all exercises.
The problem with this is that often times, those exercises are technical, and dangerous if performed in a state of fatigue. As more people started to get injured, the industry began to shift away from HIIT and back towards LISS (low-intensity steady state training). Now, many in the fitness community shy away from HIIT, proclaiming that it’s dangerous and adds too much stress and fatigue to the nervous system. Like most other things, the reality is somewhere in the middle. HIIT is a great tool to get a lot of the benefits of a cardio workout in a short period of time. But, that being said LISS and moderate intensity cardio are also important in order to effectively build a versatile cardiovascular engine.
It’s important though to dispel the myth the HIIT is dangerous, particularly for those who are older or suffer from cardiovascular disease; it’s only dangerous if you don’t use the right exercises!
In the past, cardiac rehab clinics would scoff at the idea of getting their patients’ heart rates anywhere near 90% max. It’s a shame that the stigma still exists, because a large body of research shows the complete opposite. To expand on a recent NYTimes article, HIIT has been used effectively in patients with diabetes, stable angina, heart failure, and after myocardial infarction; as well as postcardiac stenting and coronary artery grafting (1). Additionally when compared to moderate intensity cardiovascular work, HIIT has been shown to be superior for reducing blood pressure, improving endothelial function, lipid profiles, VO2max, left ventricular and overall myocardial function, as well as reversing left ventricular remodelling in heart failure patients (2). If HIIT is shown to be effective in these at risk populations, it can be pretty much safe for everyone.
This doesn’t mean that you should go and do burpees and snatches to failure if you don’t know how to do them. Stick to the bike or the erg, where there’s minimal stress on the joints. Focus on getting the proper heart rate response and you’ll be good to go.
- Rognmo O, Moholdt T, Bakken H, et al. Cardiovascular risk of high- versus moderate-intensity aerobic exercise in coronary heart disease patients. Circulation 2012;126:1436-40.
- Shiraev T, Barclay G. Evidence based exercise – clinical benefits of high intensity interval training.Aust Fam Physician. 2012 Dec;41(12):960-2.