Using Heart Rate to get the most out of your training!
The heart itself is a wondrous muscle, the strongest in the body in fact. It has its own automatic signaling system to control the frequency of contractions. It contracts on average 100,000 times per day, moving 7500L of blood through more than 96,000km of blood vessels. Our hearts allow us to not just survive but thrive! They help us climb mountains, do triathlons or even just go for a stroll. Cardiovascular fitness is an essential part of overall health and should be treated with the utmost importance. Heart disease is the 2nd leading cause of death in Canada (Government of Canadian). Avoiding risk factors for this disease as well as understanding indicators of a proficient cardiovascular system is imperative for a healthy lifestyle.
When we examine heart rate and how it pertains to exercise, it is easy to get overwhelmed by the science behind it. The goal of this blog is to simplify heart rate training to make it accessible to everyone, from recreational runners to elite cyclists. Ultimately, we use heart rate as a way to measure intensity of the work and also to gauge your recovery. It is also important to understand that while the science behind heart training is accurate, often it can overgeneralized. Remember to take the information available with a pinch of salt, knowing that no two hearts are the same!
What is exercise intensity?
Exercise intensity is defined as how hard you are working. There are two ways to measure exercise intensity, subjectively and objectively.
A subjective measurement is when a person will describe how they feel. For example, a rating of perceived exertion (RPE). Generally your trainer may ask “how hard are you working on a scale of 1-10?”. This relies on your ability to gauge your own effort but can get skewed by different perceptions of difficulty.
An objective measurement takes away bias and is not subject to personal interpretation, making it more reliable. Your heart rate is an objective measurement, making it one of the best indicators of how hard your body is working during exercise.
Intensity is important component of fitness because how hard you are working can bring about different training effects.
What are heart rate zones?
Your heart rate is how many times your heart beats per minute. Every person has a resting heart rate, the lowest rate your heart beats measured at rest, and a maximum heart rate, the highest rate your heart beats during exercise. Somewhere in between these values are your heart rate training zones.
Resting heart rate (RHR) has importance to your fitness level, indicating the health and strength of the heart. The lower the RHR the better, leading to lower risk of heart attack, higher energy levels, metabolic efficiency, and athletic endurance. This lower resting rate occurs when an increased amount of blood is pumped per contraction of the heart. It is a measurement that is taken at rest, usually first thing in the morning with an average of 60-80 beats per minute. If the heart is not as strong it won’t pump as much blood out to the body, causing the heart having to contract more often, increasing the heart rate. Every 10 bpm increase in resting heart rate increases the risk of ischemic heart disease, stroke, and sudden cardiac death. This measurement is important because it allows us to track how heart rate changes in response to exercise, using RHR as the baseline.
On the other hand, maximum heart rate is the fastest the heart will contract during exercise. The standard formula for finding your max heart rate is 220 – (your age), although this has been shown to not be as accurate as we once thought. This equation tends to overestimate maximum heart rates in younger individuals, and underestimate it in 40+ year old individuals. Another formula that is used is 208 – (0.7 x age). It ends up being a better predictor of max heart rate throughout the lifespan, but both of these calculations are based on averages of data. More current formulas that are more applicable to fitness world are heart rate reserve (Training heart rate = HR reserve x %intensity + HR resting). Heart rate reserve is the difference between your heart rate max and resting heart rate. The differences between the HRmax calculation and HRreserve calculation are the differences in the final number. HRmax produces smaller values than HRreserve, making it a more conservative measurement. Which equation is best for you? HRmax is better for older, deconditioned adults, while HRR is more accurate for younger individuals.
Everyone’s max heart rate is different. It is ultimately untrainable and is determined by age, genetics, stress levels etc. It is not an indicator of performance! The maximum number of beats per minute does not determine your fitness level, but your ability to sustain work, at max or close to max for a given period of time. Your maximum heart rate will reduce with age, although this does not necessarily coincide with a reduction in fitness. Your overall fitness is determined by diet and exercise.
Training does not alway have to be at or close to maximum heart rate. In fact, it is recommended that it is done sparingly to avoid overtraining. There are advantages to training in all zones. Lower zones work on building aerobic fitness and overall work capacity. They are also important for recovery. Higher zones, are generally trained in repeated intervals (HIIT) and develop anaerobic fitness.
Your heart rate during exercise is a reaction to work being done. The heart will pump oxygenated blood to the muscles so that they can perform the task at hand. It can be altered on a daily basis as a result of stress, environment, caffeine, lack of sleep, illness, etc. Heart rate is also affected by the type of activity that you are doing. Activities like running, jumping, hiking will place more stress on the body because of the amount of muscles involved and the need to overcome gravity and will thus, increase heart rate more than biking or swimming.
We generally contribute cardiovascular training with increases in heart rate but strength training can also increase heart rate as a result of blood being pumped to large muscle groups to move heavy load.
Measuring and calculating resting and maximum heart rate can give us information on overall health and fitness, it can also be used as a baseline to track progress. Just like weighing yourself to see if your nutrition habits are effective, conducting a submaximal heart rate test can show if your exercise regime is effective in improving your heart function. An exercise test is also a useful tool to educate participants about their current health status, create exercise programs, identify potential health risks,
Ways to measure exercise intensity without a heart rate monitor:
- Talk test
- Rate of perceived exertion (1-10)
- Manually testing heart rate (count bpm in 15sec x 4)
Heart rate zones:
How can we use zones to improve your fitness? The answer is simple, each heart rate zone will have different effect on the body. When it comes to training, variety is the spice of life! We want to be equally proficient in all zones. Think of gears in a car, we want our vehicle to have a variety of useable gears that we can call upon depending on the speed we need. Even marathon runners, regularly practice interval training at higher intensities.
To create a desired training effect, we use the biofeedback from the heart rate train within the zone specific the goal. For example, if you wanted to do a long distance run, staying within a low-moderate heart rate can help keep a sustainable pace. The intensity of the effort, and hence the HR zone correlates to different energy systems; the Aerobic and Anaerobic systems. The lower zones work on an aerobic level, meaning that oxygen is present and the body utilizes fats and carbohydrates as fuel. This system provides energy for long, low intensity, steady state exercise e.g. running 10km. When we start to increase the intensity to above 80% of HRmax (roughly), we transcend into the anaerobic systems which are designed for high intensity activity a over short duration e.g. sprinting 100m. This is a very basic breakdown of the energy systems, however, it operates more on a continuum, never just using one system but rather a sliding scale.
If you have had heart disease or may be at risk, it is a good idea to ask your doctor what are appropriate heart rate zones for you to train in.
1. 50-60% of HR Max VERY LIGHT
- Example: walking, resting. Should feel comfortable and easy
- Benefits: Improves overall health and fitness
2. 60-70% of HR Max LIGHT
- Example: Brisk walk, light jog
- Sustainable for long periods
- Recovery day training
- This zone improves general endurance & aerobic capacity
- Body will become better at burning fat as a fuel source
- Increases in capillary density
3. 70-80% of HR Max MODERATE
- Example: Running, hiking uphill, resistance training
- Improves aerobic capacity and aerobic power
- Improves efficiency of blood circulation in the heart and skeletal muscles
- Lactic acid starts to build up
4. 80-90% of HR Max HARD
- Example: HIIT, hill training, tempo runs.
- Increases maximum performance capacity
- Anaerobic Zone
- Burn more calories
- Better able to train at higher intensities for longer periods
- Your body will become better at using carbohydrates for energy
5. 90-100% of HR Max MAXIMUM
- Example: All out Sprints, 100m dash, max effort exercise
- Short period of work, long rest
- Trains fast twitch muscle fibres (Develop speed)
- Develop max performance and speed (athletes)
Indicators of good cardiovascular function:
Individuals who do not meet the recommended activity levels are susceptible to heart disease. But the good news is that changes in lifestyle can me made to reverse these ill-effects.
If you have concerns about starting a training regime, we suggest working with a fitness professional to guide you on your health journey. Regular checkups with your GP are important to track your heart health as you age.
Recovery heart rate is the amount of time it takes for the heart to return to normal levels following activity. A healthy/fit heart will recover at a faster rate, compared to an unhealthy heart. A heart rate drop of less than 12bpm in the first minute is considered abnormal. A good recovery heart rate 1 minute following exercise would be approximately 20bpm.
Indicators of good heart health:
- Low resting Heart rate
- Blood pressure
- Ability to perform same exercise with less effort (maker for improvement)
Reasons why we use heart rate monitoring
- Keeps you on track for your goals
- Avoid overtraining
- Tracking your progress over time
- Good heart health
Written by Andrea Brennan and Jessica Pastro.
Andrea and Jessica are Kinesiologists and Strength Coaches at it’s time! Fitness Results in North Vancouver.
Click here to listen to Andrea and Jessica discuss this topic with Jon McComb on the “Fitness Segment,” which airs live every Thursday at 9:05 am CKNW 980am radio.
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