Sometimes it’s hard to determine just how much is too much when it comes to training. It’s easy to overdue a workout and place yourself in a theoretical “hole” for the next workout. It can also be just as hard to determine reasons why a workout may feel great one day, and then terrible the next. With the addition of using a heart rate monitor, you can track normal and irregular patterns of fatigue, dehydration and resting heart rate. Knowing these data points can serve as biomarkers to establish baseline and threshold heart rates. With this information, you can learn from your body, and use it as a tool to prepare and recover properly for your next workout or performance.
One way heart rate monitors provide significant information is through data trend patterns. Keeping track of your day-to-day workouts can help establish trends in your fitness; this can be done with something as simple as a notebook. By using a heart rate monitor during every workout you can record the data that coincides and mark down a baseline measurement. Take for example a runner training for a 5k race: if they do a workout the first week of training that yields an average heart rate of 174 beats per minute then they can record this information and store it for future reference when completing the same workout to “test” their fitness. If this same runner performs the identical workout 5 weeks later and their average heart rate is 165 this can provide good insight to the runner’s increased fitness. This increase in fitness can be attributed to the cardiac muscle growing stronger which allows the heart to work less at the same amount of work. The heart is now “working smarter, not harder.” Measuring fitness is a key benefit of training with a heart rate monitor for athletes or anyone trying to reach a performance goal. It allows you to visually see progression which can also help boost your confidence in the training you have been following.
If you are training and performing while dehydrated, sometimes you may not realize you are in this state before it is already too late. It is true that if you only begin to drink when your body signals that you are thirsty, then you are already in a state of dehydration. If you are below 2% of water loss, you will begin to suffer from performance losses due to dehydration. Training with a heart rate monitor can help to quickly spot dehydration through statistics and not just speculation.
When you begin any form of exercise, you will undergo an increase in your heart rate. This is a normal response, and should last between the first 1-3 minutes of exercise. From this point, your body should establish a baseline heart rate and respond accordingly to increases in effort and exertion. A phenomenon that is associated to similar rises in heart rate response is known as Cardiac Drift. Cardiac Drift can be explained as an increase in heart rate over time and accompanied by a decrease in stroke volume. Stroke volume is the volume of blood pumped by the heart. This phenomenon occurs when the effort level remains constant. It has been suggested that cardiac drift is related to rises in our body’s core temperature and water loss. During an increase in our core temperature and dehydration, our body increases blood flow to the skin to help cool us down. This increase in blood flow to the skin restricts the amount of blood our working muscles are receiving during an effort. If adequately hydrated, we would not experience this upward trend in heart rate since each of our organs would not have to compete over the demand of blood flow to these specific areas.
To visualize this scenario we will take the same runner used in the previous example training for the 5k. Say this runner typically has an average heart rate of 154 beats per minute during a normal endurance run when properly hydrated. You could create an environment where the runner didn’t consume fluids for the hours preceding an endurance run and have them start the run dehydrated. Comparing data from hydrated states to dehydrated states, you would see a statistically significant rise in heart rate in the dehydrated state.
Establishing Heart Rate Baselines:
Prior to beginning a fitness or training program, it is good to establish your body’s baselines (heart rate, VO2 Max, lactate threshold, etc.) Having these baselines established can help you get the most from your workouts, and allow you to train within your body’s’ limits, not beyond them. Having the ability to realize when you are overtraining at an exact instance can help speed up the recovery process and allow yourself to get the intended benefits from a workout, not added fatigue. Once you have established baseline levels of heart rate (this is done through a VO2 Max test) you can set heart rate zones and tailor your workouts around these zones. Working in zones above what is meant to be targeted can place your body in a deficit and make it even harder to recover from than what are expected. You can also incorporate heart rate zones and thresholds to increase your levels of fitness by establishing workouts that focus on hitting high heart zones (lactate threshold) as well as holding baseline average heart rate for base season miles of running (or riding!)
There are many benefits to training with a heart rate monitor. From the science perspective, it is a good measurement for data collection. From the mental side of sport and exercise, it is a great way to visually see increases in fitness, and validation that your hard work is paying off! No matter what your goals are, fitness or performance based, the addition of heart rate based training has a place in both. From simple measurements such as knowing your resting heart rate, to high performance baseline testing, using a heart rate monitor can help you achieve success.