This is another topic that I get asked about a lot.
Is it the best way to get fit?
Is it the best system for fat/weight loss?
As with all systems of training, it's not normally the system that's good or bad.....it's how it's used and when.
HIIT is a useful method of training. BUT: the outcomes you get are always affected and influenced by the context in which something is used. As with all training systems, HIIT is only useful and safe in specific circumstances. In general terms, I prefer not to use it. In strength and conditioning at international level, high intensity sessions tend to be derived from specific diagnostics or tests. This means that athletes will always be working at a specific intensity (not simply 'high intensity) for any given workout. They would never be told to work at 'high intensity'.
If they were given, for example, a bike workout, they'd be given a specific zone of Watts to work within. On a rower, they'd be given a specific split time to work in. If running, they'd be given a set speed to go at. The requirements of the session would influence the zone they'd be in. There wouldn't be any guesswork.
This scientific method of training I've carried across to my personal training clients. Those that are training for bike events, for example, all do diagnostics tests and are provided with 7 zones of training. These zones are individual and specific to them. This means we know they can cope with the demands of any given session. We don't use anything called 'high intensity interval training'. We use zones 5-7 for very specific durations and at particular points in the training programme. It's important to remember that the harder you work, the harder you must rest. In other words, if you are working in zones 5-7, the rest period must be relatively long if you are to maintain speed. If it's too short, the speed and quality go down and you end up training someone to complete slower and slower intervals.
So, HIIT: is it the best way to get ft? This is always context-specific. In some contexts, possibly. In most, probably not. It probably does have a place and it could certainly be useful as an 'entertainment' or 'variety' session. It can also develop cardiovascular capacity. In my work, however, I would prefer that this is measurable, demonstrable and progressive for my clients. This means diagnostic tests of capacity coupled with individualised programmes.
Is HIIT the best system for fat/weight loss? Almost certainly not. There is no 'best' system. Fat and weight loss require a multi-faceted approach encompassing far more than simply HIIT or any other training system. More on this in other blogs.
Dr. Mark Mullineaux is qualified in nutrition and weight management.