When Is The Best Time To Do Cardio?

It seems like this is one of the most basic questions that come up very frequently for those fitness enthusiasts. There is no set time in the day when you make the best gains in your cardio training. It ranges differently for everyone, for example, if you feel like total crap in the morning and you need an hour or so to feel fully energized, then you obviously aren’t a morning person and you shouldn’t do your cardio in the morning. Listen to your body, know yourself, you probably would not lift weights if you were half asleep right?

Let’s first dive into the idea of doing fasted cardio, or cardio first thing in the morning after you awake. Some individuals rise at 4 A.M. just to complete their cardio for the day. You might ask, “What if I just want to lose fat, is morning cardio good for that? Is my glycogen and energy storage is low in the morning because I just fasted away all those carbs while I was asleep, so then my body will bite into my fat deposit?” Well, the answer is yes...and no! What occurs at the physiological level while you’re sleeping is your body tries to keep all of the carbohydrate storage it can to fuel the nervous system overnight with glucose (a simple sugar). So with all your carbohydrate storage being used for that purpose, and other metabolic processes, your body then naturally heads to your fat supply to get more energy and fuel. Simultaneously, it also moves to your readily available muscle protein, breaking it into amino acids (the basic unit of protein) and converting it into glucose, for more fuel. So by doing a fasted cardio routine on an empty stomach, you will actually be burning some fat for fuel, but at the cost of also losing muscle for fuel. And nobody wants to lose muscle, right? Hold on, there’s a solution. Before doing fasted cardio, consume something light and easy/fast to digest, for example, whey protein, so it can rebuild and replenish the muscle that was broken and lost during your cardio session. Don’t do it on an empty stomach.

And so, if your primary goal is to gain muscle, this is not totally ideal for you.

The next question is, “Should I do a cardio workout before or after weightlifting?”

Again, if muscle growth is your primary goal, then AFTER is your best option. If you run on the treadmill or jog outside for an hour or so before lifting weights, that long and intense of a cardio interval will almost, if not totally, exhaust your glycogen storage. Why is that a problem? Lifting weights do not utilize as much of your glycogen as a cardio session would, but it is still quite necessary. Glycogen is your muscles source of energy for contraction. With no glycogen stores, your weightlifting workout will pretty much be a waste of time. The energy won’t be there to push you through your last reps, meaning a less efficient workout. Another reason this is an issue is that during a cardio session, protein synthesis decreases, and protein breakdown increases. And then while weightlifting, protein synthesis either stays the same or goes up slightly and protein breakdown most definitely goes up. Hence, as protein synthesis (your body’s mechanism to build muscle) drops after your cardio routine, and then you pump the weights, consequently, your body’s ability to build muscle will be defective due to the cardio workout that took away the energy needed to lift effectively. Which is completely opposite for goals in weightlifting.

Doing cardio after lifting weights is absolutely beneficial for both the goals of gaining muscle mass and losing fat. Physiologically, by the end of your weightlifting session, your glycogen stores are ultimately emptied, if not, mostly drained with your body already being in a fat burning state. When you move your cardio session to post weightlifting, you won’t have any glycogen stores to burn through, so your body will target the fat supply for fuel, burning fat as a result! YES!

Remember, the intensity at which you perform your cardio workout is completely up to you and what your goals are. You can do cardio that is Low-Intensity Steady State (LISS) or High Interval Intensity Training (HIIT). An example of LISS would be running on the treadmill or riding an elliptical machine while reading a book. And an example of HIIT would be a 30-second sprint followed by 3-4 minute cool down walk to bring your HR down to the baseline and then repeating the sequence. There are specific training zones that you can train in (the percentages are based off your maximum HR): Low Intensity = 60-70%, Medium Intensity = 70-80%, High Intensity = 80%+. It’s important to know, the higher the intensity (higher the heart rate), amount of times exercised a week, and length of the exercise determines how much muscle you will lose. Heart rate monitoring has been a very essential component to athletes, trainers, and fitness enthusiasts for years and the metric can help you train better in terms of your goals such as losing weight, getting ripped, getting faster, or improving your conditioning. If you are working out with the Atlas Wristband, use Heart Rate Mode to track your training zones during the cardio session. Bottom line is, do the type of cardio that your personally prefer. LISS is safer but takes longer to accomplish fat loss or muscle retention. HIIT is quicker in achieving that, but not everybody can do it.

Happy exercising Atlas Fam!
Kevan