Defining strenuous activity or vigorous exercise is largely a matter of perception, as it depends on how hard a particular activity feels to you. Someone who is out of shape may find a brisk walk quite strenuous, while a marathon runner may not find it the least bit challenging.
Your heart rate can tell you how strenuous your body considers an exercise to be. In general, the more strenuous the exercise, the faster your heart will beat.
Strenuous exercise will make your heart beat faster, whether you're a couch potato taking a stroll around the block for the first time in months or a marathoner heading for the finish line.
Strenuous Activity Examples
Singles tennis, jumping rope, running, jogging, race walking and aerobic dancing are a few examples of strenuous exercise. Hiking uphill with a loaded backpack or bicycling at least 10 mph are also considered to be strenuous and may seem extremely strenuous if you are ordinarily sedentary. A hint that you are engaging in strenuous exercise is that you'll have to stop and breathe every few words during conversation.
Read more: Positive and Negative Effects of Exercise
Measuring Activity Intensity
Checking your heart rate during exercise can give you an honest reading of how hard your body is working. Start by finding your maximum heart rate, or MHR, which is the most exertion your heart is capable of, says Mayo Clinic.
Subtracting your age from 220 is one way of finding your MHR. A 30-year-old would subtract 30 from 220, leaving them with a maximum heart rate of 190. A 60-year-old has an MHR of 160. That means 160 is the maximum number of times your heart should beat per minute while you're exercising. Vigorous or strenuous exercise uses 70 percent to 85 percent of your maximum heart rate.
Read more: What Is a Good Exercise Heart Rate
Drawbacks vs. Benefits
Very high-intensity exercise increases the risk of injuries and can weaken the immune system temporarily while raising the risk of respiratory infection. However, vigorous workouts can also make you stronger, fight off obesity and offer a number of other important health benefits. Strenuous exercise can help fight depression and promote longevity in heart patients — and reduce symptoms of asthma, osteoarthritis and type 2 diabetes.
The Physical Activity Guidelines for Americans usually recommend performing 150 to 300 minutes per week of moderate-intensity exercise for fit adults. Those who qualify as "very fit" can do the recommended 75 to 150 minutes of cardio weekly and receive even more health benefits.
Know Your Limits
Trying to do more than your body can handle can be dangerous, cautions Ace Fitness. Over-training comes with a lot of tell-tale signs that you're over-doing it. Your decreased performance is number one, and a worrisome sign is that your heart rate remains elevated far past the time it should. Add extra fatigue, irritability and maybe even insomnia, and you've got a recipe for failure.
Take a step back and exercise with moderate-intensity cardio and gradually increase exercise intensity as your body gains strength and stamina.