This has to be one of the most common questions asked – which cardio is better for weight loss? High intensity interval training or long slow duration cardio? Both have their own merits and both are tools you should have in your toolbox. But it is important to realise that a well structured programme will also incorporate an element of strength training and you should have a healthy eating plan to follow.

interval training

HIIT training

HIIT sessions are alternating periods of short, intense anaerobic exercise with less intense recovery periods. The main thing about HIIT is intensity – you should be working hard.


  • Through HIIT training you are able to burn calories long after your training session has finished. EPOC (excess post-exercise oxygen consumption) is the body’s natural ability to return to homeostasis after exercise and you will burn calories even while resting.
  • Great for the busy person trying to fit in a lunch time session.
  • Variety of exercises and ability to change movements frequently so your body doesn’t get used to one way of training. 
  • Increases the flexibility and elasticity of arteries and veins better than long slow duration work. 
  • Here are 3 examples of Hiit training


Long slow duration training

Low intensity exercise like LSD training has received a bad reputation in the press over the last decade. It has been replaced by lunch time fitness classes designed to take less than 20 minutes and get the most from a limited amount of time. However, LSD is extremely important dependant upon your goals and ability. LSD takes longer because pace and intensity are the inverse of duration. So the longer the effort the lower the power output and heart rate. 


  • Great for beginners and can improve your overall fitness levels. 
  • Easier on the body so you can tailor to your ability, age or fitness level. Harder to do with HIIT training which requires maximum effort.
  • If you partake in a specific sport or activity that requires effort over 60-90 minutes you must add specificity to your training and train towards it. 
  • With LSD training you operate within the threshold of your aerobic zone which is good for fat loss as the primary fuel metabolised for this energy system is fat. HIIT training uses mainly carbohydrates and glycogen for fuel.

To summarise the best form of cardio depends on the amount of time you have to dedicate towards training, your ability and your goals. If your goal is to lose weight and you only have 30 minutes to dedicate towards training each session I would recommend you use HIIT sessions. However, if you were looking to improve your general health I would recommend a combination of the two. If on the other hand you are training towards a goal that requires long efforts of work (for example long distance running, hikes etc) you would be best to train with that goal in mind and opt for LSD training. 

Always make sure to complement your training efforts with the right food to help you recover and fuel yourself for training.