Most health professionals recommend that people get a minimum of 20 minutes of cardiovascular exercise 3 to 5 times per week. This is a minimum for good health, but there are a number of factors that need to be taken into consideration. For example, your current level of physical fitness as well as your own unique goals will result in differing minimum requirements.
For individuals who are just starting out, the idea is to get moving and strive for 20 minutes of activity at least several times each week. As you gain fitness and are able to increase endurance, you can incorporate more cardio into your daily exercise. At first, you might struggle to make it around the block a couple of times, but with regular exercise, you should be able to increase this to a brisk walking pace and cover more ground.
If your goal is to lose weight, gain muscle or become a body builder, the types of exercise you’ll need and the duration of those sessions will change dramatically. Generally speaking a regular routine of cardio combined with body toning or resistance exercise can help most people attain a fit and toned body. While a body builder or someone who wants to increase muscle mass will need to dramatically increase the weight they lift while also decreasing the number of repetitions.
Additionally, as people age, it becomes more and more important that they include weight bearing exercise into their regular workout routine. This can be as simple as jumping on a mini tramp, using resistance bands or taking part in a pilates class. While weight bearing exercises are certainly important, it is still necessary to continue with cardiovascular exercise as well. The weight bearing exercises are important to good bone health while cardio exercise helps improve overall fitness and heart health.
Citations:
http://www.nlm.nih.gov/medlineplus/exerciseandphysicalfitness.html
http://www.mayoclinic.org/healthy-living/fitness/expert-answers/exercise/faq-20057916