First things first ... if you think that stretching is the smart way to start your workout, you are wrong.
Stretching cold muscles can injure them. Whether you run, do calisthenics, or lift weights, it is essential to warm up first, then stretch. Warming up prepares you for exercise by gradually increasing your heart rate and blood flow, raising the temperature of muscles, and improving muscle function. It may also decrease the chance of a sport injury. Sudden exertion without a gradual warm-up can lead to abnormal heart rate and blood flow and changes in blood pressure, which can be dangerous, especially for older exercisers.
There are two techniques for warming up. The generic type — such as jogging in place or stationary cycling — is a full-body warm-up, not necessarily geared to the particular activity you’re about to perform. Because they use the large muscle groups, general warm-ups are most effective for elevating deep muscle temperature. You should always perform a general warm-up before you stretch or work with weights.
Specific warm-ups are slightly less vigorous rehearsals of the sport or exercise you are about to perform. A cyclist, for instance, would warm up by cycling at a light to moderate pace. Specific warm-ups are particularly effective in preparing both physically and psychologically for activities involving skill and coordination.
A five- to ten-minute warm-up is usually enough to raise your body temperature. A light sweat is a good indication that you have warmed up sufficiently.
Along the same vein, I can’t stress enough the importance of a cool down after exercise. Slow down gradually and take an extra lap around the track or pool; pedal the last quarter mile slowly; or stretch gently for five to 10 minutes. Not only can this reduce muscle stiffness, but it can also prevent the abrupt drop in blood pressure that occurs when you suddenly halt vigorous activity. Never sit still immediately after vigorous exercise.
When it’s cold out, many exercisers find that they stretch more fully in the comfort of their homes. So try warming up before going outdoors; also cool down partly indoors.