the structure of a running workout
The aim of a proper warm-up is to prepare your body for the exertion to come. You should be running at a lower speed than the actual running phase, and you may even want to include some stretching. This could last for 5-10 minutes.Warming up is also important prior to speed training as a way of priming the muscles. Your body prepares gradually for the actual training session, and your muscles carry oxygen more readily. Your heart rate should rise to the training level at the end of a warm-up and actual training can then begin. Some recovery sessions may be somewhat short (30-45 min) at warm-up speed.
Exercise in Target Zone
Monitor the intensity level you are at while training to make sure the session is beneficial. Your heart rate should rise towards the end of a session and not the other way around. Keep in mind that increasing speed is easy, but you should learn the basics about the way your heart rate reacts at different running speeds first.
A running session can include for example a 30-minute even-paced run at 65-75% maximal heart rate, or intervals of 5x3min at 75-85%, alternating with recovery to bring your heart rate down to 60% before the next interval. Some recovery sessions may be somewhat short (30-45 min) at warm-up speed.
The purpose of a cool-down is to slowly bring the heart rate back to normal. This is especially important after strenuous activity which has produced lactic acid/lactate. Lactic acid is easily eliminated from the system during slow-paced running. A cool-down lasts 5-10 minutes depending on how hard you trained. The harder you train, the longer the cool-down should last. A cool-down can also affect your next training session. If you haven't cooled down properly, your body will still contain lactic acid and your next training session will suffer as a result.
For optimal fitness results, train within your target heart rate limits, even if you are able to push yourself beyond them most of the time. Improving your physical condition by running is easy, but it is important to pace your development and to avoid monotony by training in a varied fashion.