You like the idea of cardio exercise and all the benefits it affords, but establishing a regular routine is another story. Trying to match your fit friends mile-for-mile or hour-for-hour will only lead to frustration and possible injury. Even if you exercised in the past, start at your current fitness level and build your stamina up gradually.
Select an exercise mode. Cycling and walking can be good for beginners because they are low impact and don't require a lot of skill. Water aerobics and gym machines, specifically the elliptical or stair stepper, are other possible options. Swimming, running and fitness classes may be too intense for your first forays.
Start with a modest goal for the first few weeks. Plan, for example, just three 10- to 20-minute cardio sessions the first week. Gradually increase the time by three to five minutes each of the following weeks until you reach 30-minute sessions. Once exercising three times per week for 30 minutes feels manageable, increase your frequency to meet American College of Sports Medicine guidelines of 150 minutes of moderate-intensity cardio weekly, or 30 minutes, five days per week.
Increase your intensity if you want to get your workout done more quickly or experience greater health benefits. Only add intensity once you feel comfortable working a moderate intensity for 30 minutes or longer. You can gradually add running intervals to your walks or hills to your rides, for example. The American College of Sports Medicine notes that 20 to 60 minutes of vigorous-intensity cardio three days per week is equivalent to 30 to 60 minutes of moderate-intensity cardio five days per week. The Centers for Disease Control affirms that doing as much as 150 minutes per week of vigorous-intensity exercise or 300 minutes of moderate-intensity exercise weekly provides you with even greater health benefits that include weight management, disease prevention and enhanced mood.