As you progress with a cardio fitness program and get the hang of the exercise thing, you may find that you want more of a challenge. Instead of being satisfied with a boost in energy and a decrease in heart-disease risk, you may want to test yourself in a 5K run or a weeklong hiking tour.
Be sure to increase your training gradually; don’t go longer, more often, and harder all at once. Otherwise, you increase your chances of injuring yourself. In other words, it’s not a great idea to do three 20-minute workouts one week and then jump to three 45-minute workouts the next. It’s more sensible to increase the time of just one of your workouts to 25 minutes and keep the others at 20.
The best approach is to increase no more than 10 percent each week. So, if you walk 150 minutes one week, walk no more than 165 minutes the next.
Treat getting into good cardiovascular shape like a really important ongoing project. You may struggle through the first session, maybe even the first five to ten. But if you stick with it three times a week for at least six weeks, you’ll start to notice dramatic changes. At that point, you’ll recover much more quickly from your workouts. Instead of going home and crashing on the couch, you may feel ready to go bowling or out for a walk.
Keep the following cardio exercise guidelines in mind:
How often you need to do cardio for maximum fitness: Five days a week is a good goal to shoot for. Most people feel best with two days off a week; everyone should take at least one day of complete rest each week.
How long your workouts should last for maximum fitness: Depending on your sport and your goal, you probably need to mix in at least a couple long workouts — an hour or more — per week. Just make sure you don’t increase the length of your workouts by more than 10 percent a week; otherwise, your risk of injury shoots pretty high.
How hard you need to push for maximum fitness: Even when you’re training to get in your best shape ever, you don’t want to go all-out every day. (In fact, only serious athletes peaking for an event should ever go all-out — and even then, only once or twice a week.) Your targetheart–ratezone includes a large range of intensity levels. On some days, stay near the bottom of the range and go for a longer workout; on other days, push harder and go for a shorter workout.