Slogging out kilometre after kilometre on the treadmill after eating 3 donuts your coworker brought in for her birthday? Do you use cardio as ‘punishment’ or to ‘earn’ your calories? Guess what, it’s a trap.
Sure, cardio burns calories. We consume calories when we consume food. We can use cardio to create what is called an energy deficit, also known as more calories out (expended in exercise) than calories in (intake from food). Unfortunately, low intensity steady state cardio, because it burns so many calories, can actually make your appetite increase.
Carbohydrate is the primary fuel source for your body during low intensity steady state exercise (any elliptical, bike, or running activity over about 20mins in duration). When your body depletes it’s carbohydrate stores, it will ask you for more. Your body can actually crave more carbohydrates after cardio. At some point you will give in to these cravings - by eating 3 donuts, or 2 cupcakes or a bowl of pasta or whatever. Then, you feel guilty (which you shouldn’t, but that’s a whole OTHER issue) and you head back to the cardio machines to burn off these ‘evil’ calories you’ve consumed. See how it’s a trap?
Please don’t misunderstand. Cardio is great. It’s good for your heart and lungs, but you don’t NEED to be doing hours every day for your body composition goals. If fat loss is your goal, you’re better off doing high-intensity interval training (HIIT) using cardio AND weights. Focus on lean proteins, vegetables, fruits and healthy fats in your nutrition and your carbohydrates will happen all on their own.
If you’re an athlete and you're training for a marathon, triathlon or some other endurance event then yes, you need to do longer bouts of cardio to train for your sport and that is A-OK. I often recommend that athletes with body composition goals focus on their sport for a duration of time (the ‘on-season’) and then take some time to focus on their body composition, if they want changes, for another duration of time (the ‘off-season’). It can be difficult to train for an endurance event AND achieve a fat loss goal at the same time simply due to the effect of training on your appetite.
Low intensity steady state cardio can have an impact on your hormones. Most specifically, it can impact your stress hormone, cortisol, and the boss of your metabolism, your thyroid gland. Exercise makes our cortisol increase, because exercise is a stress on the body. Stress is defined as any CHANGE in your life or your body from a resting state. Exercise is a good change from sitting on the couch binge-watching Netflix day in and day out, but it is still a change. If you have a lot of stress in your job, family or life in general then adding long bouts of cardio may do more harm than good for your fat loss goals.
When your adrenals, your stress glands, are in high gear from periods of stress, cardio places an added burden on them. When cortisol is out of balance, the body can store more fat. Reducing the duration of your exercise and increasing the intensity decreases the impact of exercise on your adrenal glands. This is ONE reason why HIIT works so well for fat loss.
Bottom line, if fat loss is your goal, excessive long bouts of low intensity steady state cardio might not be your friend. If running a marathon is your goal, GO FOR IT! But if you’re running a marathon in an attempt to lose fat you MAY want to reconsider. Of course, every person is unique and will have an individual reaction to training, nutrition and exercise. That’s why finding a health professional who can assist you in achieving your goals is SO important. Get out of the cardio trap and get RESULTS today!