Cardio gets a lot of hate when it comes to fat loss. And for good reason – it's as enjoyable as watching paint dry. The truth is, cardio is best used as your ace in the hole once you've dialed in your resistance training and diet.
Both high-intensity intervals (HIIT) and low-intensity steady state (LISS) variations are helpful. High-intensity intervals can be incredible for jumpstarting fat loss and improving work capacity. On the other side of the spectrum, low intensity activities like walking also will provide a ton of benefits.
LISS cardio is a great way to increase the number of calories you burn without increasing stress and creating further cortisol response. While strength training should always be your main form of activity when trying to lose body fat, it also creates a ton of stress on your body, which you then have to recover from.
The problem is, when you're in a calorie deficit, you aren't eating as much as your body needs to support that recovery. So over time this cumulative stress and under-recovery is going to wear you down, even more so if you turn every workout into an interval training session.
This is why you see bodybuilders and physique athletes adding in more cardio the closer they get to competition: It's a great way to increase the amount of fat burned without greatly increasing stress.
Low intensity activity has a number of other physiological benefits as well. It helps promote more blood flow (1), which in turn helps reduce inflammation (2) and soreness; improves cardiovascular function along with mitochondrial, and cellular health; and reduces stress and cortisol levels (3).
I generally tell my clients to take four 40-minute walks per week when bulking and maintaining. When the goal is fat loss, we increase LISS to seven days per week and keep HIIT as a next-level tactic.
- Experimental Biology 2017. How walking benefits the brain: Researchers show that foot's impact helps control, increase the amount of blood sent to the brain. ScienceDaily. 24 April 2017.
- Dimitrov S et al. Inflammation and exercise: Inhibition of monocytic intracellular TNF production by acute exercise via β 2-adrenergic activation. Brain Behav Immun. 2017 Mar;61:60-68. PubMed.
- Maglione-Garves CA et al. Cortisol Connection: Tips on Managing Stress and Weight. ACSM's Health & Fitness Journal. 2005 SEP;9(5):20-23.