Warm up is now considered an essential part of a workout or pre competition routine. While originally thought to be primarily a means of preventing injury, it is now commonly accepted that the main purpose of warm up is to improve performance with injury prevention taking a secondary role. The positive effects of warm up occur because of several mechanisms; increased muscle temperature, cardiac adaptations, injury prevention and mental rehearsal.
Increased Muscle Temperature
An increase in body temperature is one of the main physiological adaptations to warming up. The increase results from unused energy and dissipated heat produced by friction from sliding muscle filaments during contraction. The elevated temperature results in a more rapid and complete dissociation of oxygen from hemoglobin enhancing oxidative processes in the muscle and increasing VO2 max. Increased body temperature stimulates vasodilation in the working muscle increasing blood flow through the muscle and reduced muscle viscosity increasing mechanical efficiency. Nerve conduction velocity is improved resulting in faster contractions and relaxation of muscles. The heart rate increases and lactic acid production decreases after warming up. All these changes add up to improved performance following warm up.
Heart problems such as myocardial ischemia, arrythmias, and sudden cardiac death can occur during exercise. These problems tend to occur most often in middle-aged and older men. When exercise is combined with other coronary risk factors such as hypertension, cigarette smoking, obesity, and high cholesterol the risk of exercise related cardiac problems increases.
Warming up, however, may help prevent serious damage to the heart. In one study it was reported that 68% of their subjects, men aged 21 to 52, experienced abnormal ECG readings when they exercised without warming up. Jogging easily for two minutes before the training session though eliminated the abnormal ECG readings in most subjects and reduced it in the others. Abnormal readings seen during training without a warm up have been attributed to the inability of coronary blood flow to meet the demands that the exercise session places on the heart muscle.
Preventing injuries, such as muscle strains and tears, is often suggested as one of the primary benefits of warm up. Even though most coaches suggest that warming up can help prevent injuries most of the evidence is empirical and that very few, if any, studies can show that warming up decreases the incidence of musculoskeletal injuries. This is in part because during a study a researcher would never set out to injure their subjects intentionally. It is hypothesized that warming up can help prevent injuries because it stretches the muscle tendon unit resulting in a greater length for a given load; this places less tension on the muscle-tendon junction reducing the potential for injury. However, the majority of musculoskeletal injuries occur because of strength or flexibility imbalances and therefore not affected by warm up.
Warm up provides an athlete the time to mentally review and prepare for the training session of competition that follows. Visualizing the activities to follow increases nervous system arousal, increasing the number of motor units activated, improving strength and power activities and enhancing skill acquisition.
Types of warm ups
There are three types of warm ups: passive, general and specific. Each has its advantages and disadvantages.
Passive warm up
A passive warm up increases temperature through external means. Massage, hot showers, lotions, and heating pads are common forms. Although these methods increase body temperature, they produce little positive effect on performance. Several researchers have compared the effects of active, passive and no warm up on physiological markers of performance. They found that the passive warm up did not increase VO2, or decrease blood lactate levels any more than no warm up. They did find though that the heart rate increased. A passive warm up, because of increased muscle temperature, may be suitable prior to a stretching exercise but should not be recommended as the sole means of warming up for intense physical activity.
General Warm Up
A general warm up increases temperature by using movements for the major muscle groups. Calisthenics and light jogging activities are most common. This type of warm up is meant to increase temperature in a variety of muscles using general movement patterns. This is a good warm up for a fitness class but should not serve as the sole form of warm up for athletic training or events.
Specific Warm Up
The specific warm up is designed to prepare the participant for the specific demands of the upcoming activity. The specific warm up helps psychological readiness, co-ordination of specific movement patterns, and prepares the central nervous system. A specific warm up usually consists of a simulation of some technical component of the activity at work rates that increase progressively. For example, an Olympic weightlifter will perform the snatch with heavier weights progressively until reaching 80-90% of the opening attempt. Because of the rehearsal component of this type of warm, it is the preferred method for sports activities, particularly high speed and power activities.
Designing a warm up
A good warm up has both a general and specific component and may include a passive component if the athlete feels they perform better when they use some sort of a topical analgesic like Tiger Balm.
General Warm Up
Full body Calisthenics
A warm up starts with some full body calisthenics. Exercises like jumping jacks, rope jumping, push ups, sit ups, and lunges are full body exercises that will increase body temperature. These exercises should be done for only 1- 2 minutes at a time as the goal of warm up is to increase temperature not create fatigue.
Dynamic stretching is a more effective means of warm up stretching than static stretching, meaning that rather than holding a stretch for a period of time you move through a full range of motion and then back to your starting position immediately without holding the stretch. This is particularly true when you are doing power training. Several studies have shown that a static stretch immediately before power training can significantly decrease subsequent power development. This is because the static stretch decreases the effectiveness of the stretch shortening cycle.
Duration of General Warm Up
The amount of time needed to warm up depends on the type and intensity of the activity as well as environmental conditions. For someone engaged in a light jogging program 10 minutes may be sufficient for a warm up. Elite level athletes may require 30 or 40 minutes to warm up depending on the nature of the event, with higher intensity events requiring longer warm ups. Exercising in a warm environment requires a shorter warm up than exercising in a cold one. In a normal environment the onset of sweating is usually a good indicator that body temperature has increased sufficiently.
Specific Warm Up
The nature of the specific warm up depends on the activity to follow. Keep in mind that warm up is just that warm up not training, fatigue should be kept to a minimum during warm up otherwise the training session will suffer.
Warming Up for Strength Training
When weight training, do at least two sets, one at 50% and one at 75% of the work weight, before using the working weight. Very strong people need to do more sets. Many elite powerlifters and weightlifters use six to eight warm up sets prior to opening attempts in competition. Repetitions in warm up sets are low, 1-4, and done at a controlled speed. Warm up sets are done for every exercise in the program, not just the first exercise.
Warming Up for Speed, Agility and Power Training
As in weight training a warm up for speed, agility and power events or training uses warm up sets. Prior to each drill start with a walk through set that allows you to rehearse the drill in your mind and remind you of the movements and changes of direction that have to be made. Following the walk through perform two progressively faster trials, one at about half speed and one at three quarter speed. Be sure to focus on good technique during each of the warm up sets, the way you perform in warm up will be the way you perform in the training session.
Warming Up for Aerobic Training
Since most of the aerobic training you will be doing is low intensity there isn’t a specific portion to the warm up. If you were to do higher intensity aerobic intervals you would start with 10 –15 minutes of light jogging prior to starting the interval portion on the session.
A good warm up can make the difference between an adequate and a personal best performance. If you are having trouble int eh early parts of an event or seem to get a second wind take a look at your warm up it may need some fine tuning.