When thinking of slimming down/cutting, a lot of people will turn to cardio. It’s a word that embraces a lot of things, but the simple act of cardio is as small as going for a walk, or anything really that requires movement. A lot of people focus on just performing their exercise, and don’t consider much about the timing of it. But cardio can have varying effects depending on when, and what type is performed.
Common sense ideas
The most obvious way to divide cardio into types is to differentiate by the level of intensity. You can perform high-intensity cardio, for example sprints or trying to break a 5k personal best on a rowing machine (or on the river for that matter) – or low-intensity, like the casual run around the block I went on this morning.
Which type you should perform depends entirely on your goals; Short, intense bursts of exercise are shown to be more beneficial for fat-burning than long, low-intensity exercises. However, the roles are reversed when it comes to maintaining or trying to build mass – low-intensity cardio or none at all is definitely the way to go.
The next thing to consider is recovery. If you train with weights – it makes sense to avoid performing cardio the next day that will put strain on muscles you worked not long before, so that they have time to recover. Especially if you dedicate a session to just legs, then going for a run the next day is going to be unpleasant and not particularly beneficial if your aim is muscle size and strength.
Not so common sense – cardio timing
That’s the two kind of obvious things out of the way. So now onto cardio timing – when you should perform cardio to maximize its benefits to your goals.
Cardio timing is all about making sure that you’re prioritizing fat burning when you’re performing exercise. You may have come across the idea of morning cardio – the idea of going for a run/swim/bike/whatever practically upon waking, and before breakfast. In fact, there’s plenty of people that will get up extra early just so that they can get the benefits of this method (Dwayne ‘The Rock’ Johnson is one of them).
The general idea is that you’ve been fasting the whole time you’ve been asleep, and the more time the body goes without food – the more it prioritizes burning off fat for fuel. The graph on the right is how the body partitions it’s fuel sources over time after a meal. Where the lines cross – at 8 hours in – it’s about a 50-50 split between fat and carbohydrates. Most people sleep for 7-8 hours, and eat dinner at least 1-2 hours before hand.. so when they get up and do cardio in the morning – more than 50% of the fuel used in that workout is fat.
In the same vein as morning cardio, when you’ve just had a heavy weights session – your body will have used up the majority/all of its readily available fuel sources (carbs), and be running predominantly on fat. So if you run for say 20 minutes after a weights session – you’ll be burning almost entirely fat.
This can have a trade-off with muscle though, as performing cardio without anything left in the tank can cause the body to turn catabolic and start stripping it’s own muscle for energy. If you do choose to perform cardio after weights, the best recommendation is a very low-intensity run, or cycle.
Cardio can be a great tool to burn more calories – meaning you can eat more while on a diet – or you can use it to shock your body out of a plateau, actually if you visit any fitness training facility like a gym or a yoga studio you’ll run into instructors that will all verify this. There are many, many different types – some people even attach ropes and drag cars as fast as they can for 30 second intervals, as a very intense form! – but it’s all mostly down to personal preference. Sprints/football during summer and jogging during winter are where it’s at for me – just try and avoid doing it in front of kids, cause they can be mean and laugh at you.