Concrete is made by using cement and sand combined together to make a strong material. Cement will not hold in place well, and sand is not solid enough so you need both. If you want to lose weight fast you have to exercise, but to lose it effectively, you need to combine cardio movements with strength training routines. Any professional athlete will tell you they do both.
It is wise to begin with an aerobic program each and every time you exercise to warm up for 15-30 minutes. Your heart is essentially like a pump so cardio exercise, ie jogging, gets your blood pumping. It raises your metabolism rate which in turn sends oxygen and energy to your muscles to prepare them for movement. Your muscles need that in order to function without becoming strained.
Cardio exercises puts your whole body into motion. It takes your body from sedentary to actively moving. It literally gets the juices flowing similar to a car engine. You are not going anywhere on your weight loss journey until you put the pedal to the metal. That is where weights come in. It is true that a cardio workout boosts the heart, and to some extent the brain, stomach, liver, kidney and lung. These are called the visceral or involuntary muscles. They function without your help, as you do not have control over them.
In addition, using weights as part of your exercise regiment utilizes the other muscles, the ones under your skin, which are called striated muscles, along with the tendon and ligaments. You can consciously move these muscles. Weights add resistance which make these elastic muscles stretch and contract. This is called anaerobic repetitive movement that pumps nutrients into the muscles. However, real weight loss and fat burning occurs afterwards. Strength training by using weights keeps the metabolism levels boosted for up to six hours. Weight repetition tells the muscles to notify the brain they need calories so they can be replenished with nutrients.
Back to the car analogy, gas has to be pumped into the tank before the vehicle can run. It is wiser if cars get gas when they are turned off and at rest. Strength training depletes the energy in your muscles, so the tank is empty. After using weights, the muscle group that was exercised signals the body it needs to be refueled. The body takes the fats and converts them into fuel and delivers them to the muscles so you can lose weight fast.