How confusing right? Actually no. There are many ways to do cardio, & all of them have a valid place in any fitness or weight loss program – what sort depends on your goals.
LSD (or Long Slow Distance) is cardio performed over a longer period at a lower heart rate, generally between 60 & 70% of your Maximum Heart Rate. It has long been thought to be ‘the thing’ to burn fat & get you to your weight loss goals.
Then HIIT came along. HIIT (High Intensity Interval Training) is cardio performed in short bursts at near 100% effort, with recovery periods in between. Sounds hard right? Well, simply put, it is. Yes, it’s tough, but it’s also a sure fire way to significantly improve your fitness & rev up your results.
LSD is great for those with bad joints, heart conditions & special populations. Basically the more overweight & less fit you are, the more LSD would be the right thing to start you off with. Yes, LSD does burn a greater percentage of total calories as fat, but it takes a long time to get there. With today’s hectic lives we lead, do we want to be in the gym for any longer than necessary? No. Didn’t think so.
HIIT sessions are generally well over and done within 30 minutes – if you can stick it that long. I said it was tough. For more detailed reading on HIIT check out Cardio and Programming which is a bit of a summary of a guest blog written on the Robertson Systems website by Mike Boyle. It’s an eye opening article and well worth a read.
The maximum intensity bursts increase your heart rate & intensity and kick up your calorie expenditure. HIIT also has a greater ‘after burn’ effect than LSD; so you’ll keep burning calories longer. HIIT pushes your metabolism through the roof and you get super fitness benefits to boot. HIIT is just the ticket for anyone who gets bored easily, is short of time or likes to push themselves. Although you’ll burn less fat as a percentage of your total calorie expenditure than with LSD, chances are your total calories will be about the same as, or even above your LSD session. Just in half the time.
The graph below illustrates my point.

The sessions explained:
The workout LSD workout was 10 minutes longer, but burnt 217 less calories, despite the higher percentage of fat calories burnt through the session. Why’s this important? Weight loss is all about calorie balance – the more you burn the more you lose! Simple.
So while LSD might be better know, and more commonly recommended for fat loss, unless you have some medical or physical condition stopping you from performing it, interval training is the way to go to achieve better fat loss results. While the HIIT session used for illustration purposes might have been extremely tough and only applicable to trained subjects; members of the general public will see greater fitness and fat loss results if a few harder intervals, or hills, are added into their program. Gradually increase the amount of intervals, or hills in their program until they are performing higher intensity work for approximately a third of their workout time and go from there.
A cautionary note before you jump in too deep - this is a personal account of two workouts performed by a highly trained client. This blog is in no way a recommendation of workouts to be performed, or a prescrptive service to members of the public. Perform all HIIT training with caution; and with a well qualified personal trainer if possible.
