Over the past couple of months, we’ve touched on two of what we call the 4 “F”s of Fitness – Force (strength training) and Flex (flexibility training). This week we’re going to dig into the next F of fitness: “Fast” – or interval training. 

Sprint interval training, speed work, high intensity interval training, and high intensity intermittent exercise are all considered “fast” workouts. Simply – any workout in which you are varying the pace of your workout session. Interval training usually consists of alternating between very high-intensity exercise bouts, interspersed with a rest or low intensity exercise period. The duration and intensity of the exercise bouts varies depending on the protocol, however improvements in fitness and health have been measured after exercise training bouts as short as 20 seconds! 

In our newsletter on strength training, we briefly touched on the different muscle fibre types. Your body has two main kinds of muscle fibres: type 1 fibres, which are used primarily for long endurance activity, and type 2 fibres (which can be further broken down into Type IIa and Type IIb), which are used for activities that require strength and speed. One of the reasons why interval training is so good for you is because it engages both your aerobic energy system and type I muscles, which are used for endurance, and anaerobic energy systems and type II muscles, which are used for power and speed. By engaging multiple energy systems and muscle fibre types at once, interval training is one of the most efficient ways to improve your overall fitness and health!

What’s more, with this type of training, you can reap the benefits in a very short amount of time. Even a few very short bursts of activity spread out throughout the day can significantly improve your fitness. However, the problem remains that unless in a study, people still struggle to get over the mental hurdle of incorporating interval training into their fitness routines. The idea of doing a really intense workout can be very daunting for many people.

If you’re someone who is nervous about interval training, here are a few key take-aways which will hopefully help you to finally get out there and try it!

1. There are so many different ways you can incorporate interval training into your life: running sprints, spin classes, circuit workouts, hills, stairs, team sports, etc. And then even within these categories, you can mix up the number of intervals, the length of the intervals, as well as the rest periods. The options are endless. Have fun mixing it up! 

2. If your joints or other health conditions prevent you from doing anything too high impact, you could walk some stairs or speed walk up a nearby hill. 

3. As mentioned above, this type of training can take very little time. So if you find it hard to fit exercise into your schedule, this is a good option for you! Try going for a few quick flights of stairs in between meetings or a 20-minute circuit workout before or after work. 

4. Have fun! Interval training can be a formal workout, such as a spin class, or it can be something as informal as playing with your kids in the park or a team sport that requires you to do short bursts of activity (when we’re allowed to do those again!). 

There are so many different ways to incorporate speed work into your life. It’s not always about running sprints around a track. Find out what you like and what you think you could incorporate easily into your life.

Finally, we would never discourage you from doing endurance training so if going for a long jog is your thing then stick with that! This is just another way you can get health and fitness benefits in a very short amount of time.

Have fun!


Greg Wells is the CEO and founder of Wells Performance, a global consulting firm on a mission to elevate how we live our lives at work and in life. He has worked with some of the highest-performing individuals on the planet, including Olympic and world champions and elite organizations including General Electric, BMO, Deloitte, KPMG, BMW, Audi, Sysco Foods, YPO and Air Canada. He is also committed to inspiring children and young adults, working with school boards and independent schools around the world.