<aside> ✍🏼 This chapter is authored by Manu Konchady
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A bicycle is one of the most efficient and fun modes of transport. Among human powered vehicles, none can match the efficiency of a bicycle. The bicycle is one of the few human powered machines that uses muscles in a near optimal way. Since leg muscles are among the most powerful muscles in the human body, attaching a crank and pedals to a wheel was an obvious way to power a bicycle. The use of pedals to harvest human energy was common in other machines such as lathes, saws, cutting machines, and power generators.
The circular pedalling motion uses the powerful thigh muscles or quadriceps to power a bicycle. Most of us can generate sufficient power to ride a bicycle - other factors to consider when riding a bicycle are matching individual power with the load. Each of us is unique and has the ability to generate varying amounts of power for some duration. A professional cyclist can generate 300+ watts [A watt is the product of force and velocity. One horsepower (HP) is 746 watts] for several hours and is roughly twice as powerful as an amateur cyclist. If we assume that you can generate 125 Watts, then in an ideal situation you would match your generated power to a smaller load than the load of a professional cyclist.
A geared bicycle makes it possible to adjust the load to match your generated power. At a high gear for a faster speed, the load is proportionately higher compared to the load for a low gear. If you attempt to generate more power than your body is capable of for a sustained period, then you are certain to tire soon and end your ride. However, with a geared bicycle you can adjust your load such that it matches your generated power. The addition of gears and derailleurs (see Glossary) to a bicycle made it possible for the average rider to travel long distances without becoming exhausted.
You need some mode of transportation to get to work or shop and a bicycle is a great alternative to the common motorized vehicle options. You may even find that you sometimes reach your destination sooner on a bicycle than with other vehicles. While spending time riding to work or on an errand, you are actually burning calories as well and possibly saving time and money visiting a gym. At first, you might find riding a bicycle is slow and tiring. It may also be discouraging to note passengers in motorized vehicles overtake you effortlessly. However, in a congested city, the differences in commute times between a bicycle and other vehicles is not as much as you would expect.
One of the benefits of riding a bicycle besides saving money on fuel is improved health. A study [1] of about 14, 000 people has shown that riding a bicycle for just 30 minutes a day reduces the risk of type 2 diabetes by about 40%. Another study [2] of 2400 individuals showed that people who rode about $2{1\over2}$ hours a week were nine years "biologically younger" than their sedentary counterparts.
Manage your Weight
Among the health benefits are a stronger heart, close to ideal weight, and improved joint mobility. An average male and average female consume about 2500 and 2000 calories per day respectively. If you burn more calories than what you consume, you are more likely to lose weight. You could also consume less calories (go on a diet) and similarly lose weight.
However, riding a bicycle and burning calories is definitely a better option than going on a diet – not only is it more fun, but you can eat at least some of the food that you would have avoided on a diet. If you ride a bicycle for an hour at a moderate pace (20−24 kmph) you can burn roughly 500−600 calories. This of course depends on the gradient of your ride - a climb would mean an even higher burn rate while a downhill ride will do the opposite.
The amount of energy (calories) that you need to function in a day while resting, varies from person to person. This rate, also called the “BasalMetabolic Rate” (BMR) is the number of calories required to support your normal body functions. BMR is roughly calculated using the Mifflin St. Jeor Equation – $10 × w + 6.25 × h + x$ where $w$ is your weight in kgs., $h$ is your height in cms. and $x$ is +5 for males and −161 for females. Over time as you continue to ride and your fitness increases, your BMR rises and therefore you burn more calories even when sedentary.
In theory, you should be able to control your weight by simply managing calorie intake and calories consumed through exercise and BMR. However, all calories are not equal and how the body processes calories depends on the source. All the calories from fibrous foods may not be absorbed while calories from proteins may require more energy to digest and there is some margin of error in food labels. In general, processed foods require less energy to digest than natural foods.
The benefits of a ride do not end when the ride ends. Following a ride, the body continues to consume calories at a higher rate than the normal rate without any exercise. Cyclists who rode vigorously for 45 minutes burned an additional 190 calories in the 14 hours following a ride compared to days when they did not ride [3].
There is no universal agreement on an ideal weight per person. The Devine formula for a male who is 67 inches tall in kgs. is $50 + 2.3 × (67 − 60) = 66.1$ kgs., similarly for a female of the same height it is $45.5 + 2.3 × (67 − 60) = 61.6$ kgs. The ideal weights from other weight formulas are in a range of ±5% of the values shown. The Body Mass Index (BMI) is another value to check if your weight is within a healthy range. It is the ratio of your weight in kilos to your height in meters squared. So for a person who is 67 inches (1.7 meters) tall and weighs 66 kgs., BMI is ${66.0\over1.7^2} = 22.83$. A BMI in the range of 18 − 25 is generally considered healthy.
Generally, gaining weight is considered easier than loosing weight. Further once weight is lost, it takes some effort to keep the weight loss permanent and prevent a gradual increase to the original weight. Cycling like other physical activities consumes calories and the intensity of your ride is proportionate to the number of calories consumed. A ride on unpaved or pot holed roads will burn more calories than a ride on a smooth road. Finally, the best way to burn calories is to ride uphill at a moderate pace – not only will your heart rate and power output increase, the number of calories consumed over a short period will rise sharply. So, if you do not have the time for long rides, then riding up and down hills is a great option to get a quick workout that is as beneficial as a longer ride on flat terrain.
Caveat: Since bicycling is a form of exercise, you will have a stronger appetite following a ride. Losing weight by consuming fewer calories and burning more calories through exercise, is hard to accomplish. Eventually you may end up consuming as much or more calories necessary to regain the lost energy. Therefore, bicycling will help you maintain your weight, but not necessarily lose weight.