Often when I hear people talk about their workouts, somewhere in there, they talk about how many calories they burned, and many people judge their workouts on that number. What if I told you that the calories you read from your Apple Watch or FitBit are just guesses?
Everyone knows I love fitness trackers and think that they are great and should be worn. The problem is that people only look at one metric nowadays, and that is calories burned, and even the most accurate fitness trackers could be a minimum of 30% off. It is crazy to judge the validity of your workout on something that is just guessing.
During your workout, you need to watch your heart rate more than the calories. Bottom line is you have to understand your workout zones to get any real feed back from a heart rate tracker.
For most people, the goal of each workout is to increase fitness and burn fat. Burning fat is actually what people are thinking is happening when they look at calories burned.
The problem is fat burning doesn’t take place right away. Your workout usually starts by burning carbohydrate calories first. This is generally done by burning the immediate energy source, which is blood sugar (glucose) followed by carbs that are stored in the muscles called glycogen. After these fuel sources are used up, your body will switch over to fatty acids.
Your body cannot immediately jump right to fatty acids, it has to get warmed up first. Think of the burning of the carb calories as it prepping to burn fat. Fat is only burned when there is enough oxygen in the bloodstream to tap into the fat storages our bodies have. The key to staying in this fat-burning zone is going at a pace that allows for consistent movement and consistent breathing.
Using a fitness tracker for this is vital. We want to warm up to burning fat, and the way we do this is by watching our heart rate at the start of a workout. If very quickly (inside of 3-4 minutes on workouts that are meant to be mid-range or longer) you are 90% or higher in a workout, your body is likely never to make it to the fat-burning zone because there is not enough oxygen in the bloodstream.
The CrossFit program is not like other programs that use fitness tracking like Orange Theory or Running. Because of the combination of high-intensity functional exercises as well as regular resistance training, watching the heart rate could be a bit misleading. The reason why CrossFit has been so successful is because of the constantly varied workouts. We have short, medium, and long workouts. We use different pieces of equipment as well as various movements every single day. We focus on relative intensity, and this is what drives results. This also causes fluctuations in the heart rate and makes tracking heart rate a little different in a CrossFit class than in an Orange Theory class.
If you run at a single pace for 5:00, you will see a gradual increase in heart rate. Compared to a CrossFit workout where inside 5:00, you may run 200m (1:00) followed by 15 Back Squats at your body weight (1:30), then into 15 Burpees (1:00), and then in the remaining time (1:30) as many Kettlebell swings as you can, your heart rate will alter four different times. This is also why the CrossFit program has such a long residual burn of calories post-workout compared to other programs.
So the natural question is, “How do I maximize fat burning time in a CrossFit workout if my heart rate isn’t allowed for a gradual increase through a single modality?” The answer is simple. Warm-up hard and start your wods out easy. The people who gas out more often than not are those who “sandbag” or skip the warm-ups in general. The best looking and fittest athletes are never the ones that are doing this. There is a reason. At our gym, our warm-ups are very similar to our workouts. The movements may not be the same, but the motor patterns and stimulus are. With a proper warm-up, your body is prepped and ready to move into the fat-burning zone. Then, if the wod allows, ease into it and finish it hard!
This exact concept is why CrossFit Games athletes look the way they do. The difference between them and us is that they can control their heart rates even with high-intensity multi-modal workouts. Our goal is to continually increase our fitness so that when we are easing into workouts that allow it, we are still moving quickly, and finishing workouts fast.
Having a heart rate monitor will enable us to track this. Looking up and seeing what zone you are in by seeing a color gives you immediate feedback on what you need to do. If you are two minutes into a fifteen-minute workout and are showing red, you know you need to slow down and spend some time at a lower heart rate. There is no guessing, its immediate. This will allow you to build your capacity in a way this is unlike the prevailing thought of the CrossFit method of beating yourself down.
If you have plateaued or continually feeling beat up from workouts, proper heart rate tracking could be the key. If you are interested in more information on heart rate tracking, send me an email!
Richard