If you're torn between taking an invigorating walk and pedaling down a scenic path, rest assured that either choice can provide a healthy aerobic workout. Walking has the advantage of being free and simple -- you only need to step out the front door to get started -- while cycling requires equipment but offers more speed options. Ultimately, the most beneficial activity is the one that keeps you coming back for more, as frequency is the key to improving your body through exercise.
As cardio exercises, walking and bicycling both lead to a stronger heart that pumps blood more efficiently through your veins. Engaging in cardio also revs up your immune response so you can better fight off viral and bacterial infections. With regular cardio, you'll likely see healthier cholesterol levels and lower blood pressure, paving the way for a future of good cardiac health. Both activities even cause your brain to release endorphins for increased happiness. However, neither walking nor bicycling offer the muscle-building benefits of strength training -- you should perform resistance exercises such as lifting weights or doing pullups two or three days per week.
When it comes to building stronger bones, walking has a major advantage. That's because walking is a weight-bearing activity, forcing your muscles to work against gravity, while bicycling is not. Weight-bearing exercises work to build bone density, helping to prevent bones from weakening later in life. Strength-training moves also provide this benefit, so resistance exercises are even more important if you choose the bike over your walking shoes.
If calories are your main concern, cycling has an edge. Walking at a rapid 4 mph, a 155-pound woman burns around 167 calories in 30 minutes. Even racewalking at maximum pace, she only burns about 242 calories in the same time. In contrast, she burns about 298 calories in 30 minutes cycling at 12 to 13.9 mph, and torches an impressive 372 calories in that time cycling at 14 to 15.9 mph. It takes a deficit of roughly 3,500 calories to shed 1 pound of body fat.
For aerobic health benefits, fit moderate cardio into your schedule 150 minutes per week, or get 75 minutes per week of vigorous cardio. Sessions should last a minimum of 10 minutes each. If you go the walking route, maintain a brisk pace of at least 3.5 mph for a moderate workout, or racewalk at 5 mph or faster for a vigorous workout. On the bike, cycling at 5 to 9 mph offers moderate cardio, while speeds of 10 mph and faster provide vigorous cardio. If you're new to exercise, speak with your doctor before starting a new regimen.
- MayoClinic.com: Aerobic Exercise: Top 10 Reasons to Get Physical
- American College of Sports Medicine: ACSM Issues New Recommendations on Quantity and Quality of Exercise
- MedlinePlus: Build Up Your Bones
- Harvard Health Publications: Calories Burned in 30 Minutes for People of Three Different Weights
- Centers for Disease Control and Prevention: General Physical Activities Defined by Level of Intensity
- Kraig Scarbinsky/Digital Vision/Getty Images