Cardiovascular training (short "cardio") are aerobic exercises that mainly aim at increasing endurance such as running, cycling, swimming or walking. There are a lot of theories and opinions around cardio training and especially the effect on strength or muscle growth, many of which are contradicting. Fitness Youtuber Jeremy Ethier analysed this in his video. In this video he also referred to a study which examined the interference of aerobic and resistance exercises.
The bottom line is that it is all about the amount and timing of cardio. As always it needs to be in line with your goals. I just recently completed a Spartan race which requires to train a diverse set of fitness aspects. This makes programming more challenging but cardio is a crucial element. It "just" has to be factored in correctly.
As part of the Spartan race preparation I mixed in two types of cardio:
- High intensity interval training (HIIT)
- Low intensity steady state cardio (LISS)
High intensity interval training (HIIT)
Low intensity cardio, also often referred to as low intensity steady state cardio (LISS), is great because it does not add additional training stress on your body. You should generally try to walk as much as possible (take the stairs instead of the lift). There is also a lot of research around fasted cardio, which is not yet conclusive regarding the real effect on fat loss. However, a recent study suggests that fasted exercise alters gene expression of certain enzymes and may stimulate your body to burn fat more effectively. For the Spartan race I did one to two brisk walks per week fasted in the mornings.
Low intensity steady state cardio (LISS)
High intensity interval training (HIIT) is very effective with respect to burning fat with less time investment. One of the reasons why HIIT is so effective is that it increases the post-exercise oxygen consumption (EPOC). Because the intensity of a HIIT workout ideally was very high, it takes the body longer and more energy to get back to its resting state. For this the body burns additional calories even after the workout, which is also referred to as the "afterburn effect."
There are many HIIT programs available (like Tabata) and generally these suggest to have several alternating work and rest periods. For example, after your resistance training session incorporate a eight sets of 40 seconds fast spinning with 20 seconds rest (slow spinning) in between. In your work periods you should go all in and give everything you have. Some types of exercises we like for HIIT are rowing, airbike, spinning, sprinting, rope jumping, Kettlebell swings, boxing or Thai boxing.
Cardio is great and very complementary. It always depends on your goals and then the correct programming in terms of amount and timing of your cardio sessions accordingly.
For more details about how cardio fits into the bigger picture of the 4 Legs Fitness concept, check out our book From Healthy to Athletic: How to Master the 4 Ingredients to Superior Fitness.