When it comes to workout, simply doing push ups and sit ups is not enough anymore, especially now when science has been analyzing the efficacy of each exercise and each type of workout. It is obvious that to create the most efficient exercise schedule, just performing a bunch of favorite exercises for arms, torso, abs and legs will not create the best possible effect.
Cardio and strength (muscle) building are basic forms of exercising, which utilize muscles differently and which also results in a different shape of the muscles. Cardio workout will create lean muscles, while mass building will create a bulked up effect (as in bodybuilding). Another big difference between those two forms is in the presence of oxygen. Oxygen is used in cardio workout simply because contractions in that form are slow and that allows oxygen to get involved in the muscle contraction process. Lactic acid is not built up in this way, which means the exercise can be performed for a long period of time. Opposite things happen with muscle mass building. Since muscle mass building needs the use of additional weights. To lift that weight, explosive and fast contractions are needed and there is not enough time for oxygen to get involved. This means that lactic acid will accumulate quickly and end the exercise in a short time.
What has to be known about endurance workouts is that those are not generally performed by beginners. It should be done after some period of exercising when the training session is not difficult anymore, which is a clear sign that the body has gotten used to that specific schedule and it should be changed. For example, when it comes to running, if it is jogging, it has to be combined with sprints in order to change the tempo of the exercise. It will activate same muscles in a different way and will increase the overall physical condition of the body. If a treadmill is used, the incline can be changed, which will additionally change the exercise and create some more resistance. This is a cardio endurance workout, but there is also muscle endurance workout, which is emphasizing additional bulking up and strength stimulation.
It is also essential to use proper eating, whichever type of workout is used, especially if workout is strenuous and physically demanding. Then enough nutrients, vitamins and minerals have to be inserted with meals. Of course, if needed, supplements could be used for additional energy boost, increased muscle growth, muscle recovery etc.