Body Temperature Responses to Exercise
One of the by-products of energy production for exercise is the generation of heat. The greater the intensity and duration of exercise, and the more muscle tissue that is used - the more heat is 
The body’s major immediate response to this accumulation of heat during exercise is to increase the flow of blood to the skin where it can cool with the aid of sweating.
While many types of strength, power and speed training use lots of large muscle groups and are high intensity, they are generally very short in duration with long rests between sets/intervals.
Consequently the body temperature increases with these types of training are minor as the actual time spend 'producing heat' is actually quite short. While the body temperature may increase slightly, the body's temperature typically returns to normal within 20 minutes after the exercise has been completed.
This is why we don’t tend to see people competing in events such as power-lifting, javelin and sprinting dripping with sweat or with their face’s flushed with blood. Quite simply, they haven’t generated enough heat to warrant a major cooling response from the body.
If the workout progresses it becomes increasingly important to consider the accumulation of heat and employ cooling strategies such as the use of fans to aid cooling if they are available.
It is also important to ensure people are well hydrated which enables continual heat to be lost through sweat and that their training clothing is appropriate.
As the intensity of longer duration continuous type exercise increases blood gets shunted to working muscles as a priority over the skin for cooling. Because of this, care should be taken with long duration high intensity exercise in hot environments as it can result in core body temperature rising to dangerous levels and development of heat stress, heat stroke and if unchecked...death!
The greatest accumulation of heat occurs with training for anaerobic fitness and muscular endurance as higher intensity work periods generate more heat and with short recovery periods more heat accumulates than can be dissipated during the short recovery periods.
For these reasons it is imperative to check and protect your clients from overheating if they are taking part in these types of training. It would be normal for people to sweat, have flushed skin and be thirsty. When these 'normal' responses give way to signs of excessive exercise stress such as pale skin, loss of co-ordination, and/or minimal sweating then it is imperative you recognise these signs for what they are and act accordingly to protect the wellfare of your client (or anyone who is exhibiting such signs). Check out the pages on 'exercise risk assessment' in the training delivery folder at ptdirect.com for more information on risk factors and exercise stress.
As more heat is accumulated with training for anaerobic fitness and muscular endurance (and to a lesser degree hypertrophy and aerobic fitness training) it will take longer for the body to cool once the workout has finished, possibly up to 40 minutes as heart rates and breathing rates stay elevated to help return the acid-base balance, expel carbon dioxide and dissipate heat.
