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marathon runners found that stretching was significantly associat- ed with an increased injury rate (2). It has also been suggested that an increase in joint mobility resulting from stretching, increas- es the risk of injury due to the decrease in joint stability (3). Another research group showed that the most flexible and least flexible subjects in a military cohort had twice the injury rate when compared to the group with average flexibility.

More importantly however, is the growing body of evidence that acute stretching impairs performance in subsequent tasks requiring maximal muscular strength (4), muscular power (5, 6) and muscular strength endurance (7).

While the reasons or mechanisms for this reduction in muscular strength and power are still not clear, we do know that this reduction can last for up to an hour (8). It is hypothesized that muscular strength and power require a stiff musculo-tendinous unit and that stretching reduces this stiffness. As a consequence, stretching means that some of the strength and/or power produced by the muscle is absorbed by the less stiff musculo-tendinous unit resulting in a lower maximal strength or peak power output.

A dynamic warm-up, understood to mean a warm-up without the stretching and comprising of gradually progressive, dynamic movements, began to evolve as a result of this research as well as the anecdotal evidence, reported by strength and conditioning professionals (9, 10, 11).

With sufficient evidence that static stretching should be excluded prior to training sessions and competition where maximal strength, power and or strength endurance are the objectives, the question was how to structure such a warm-up. Unfortunately at this stage practice leads sport science in that there are no published applied studies indicating best practice. Dynamic stretching is defined as consisting of ‘functional-based exercises which use sport-specific movements to prepare the body for activity.’ (9). One of the most important advantages of the dynamic warm-up is that a sport- specific technical component can be included in the warm-up. This

means that the strength and conditioning coach and the technical coach need to collaborate in the design and delivery of the warm- up. This technical element can be the introduction of a new skill at low intensity, the introduction of the theme for the training session that is to follow, or reinforcing a tactical practice prior to compe- tition. Consequently, if planned well this represents a time saving tactic as well as an opportunity for the relationship to develop between the technical coach and the strength and conditioning coach.

A further advantage of the dynamic warm-up is that it allows both the strength and conditioning coach and the technical coach to conduct an informal assessment of the athlete. This is very useful with new athletes as it allows the strength and conditioning coach to get a fairly rough idea of functional flexibility in selected exer- cises for a number of athletes at one time. This is also achieved without the athlete thinking that they are being tested. Over a period of time, the coaches can develop simple methods of assess- ing an athlete’s condition during the dynamic warm-up, by monitoring the depth of the body weight full squat for example.

The benefits of static stretching are well established with regards to increasing flexibility or range of movement around a joint. As with any other training modality such as strength training or speed development, stretching should be prescribed where increased flexibility is required in the preparation of an athlete. This form of training, however, should be delivered as a stand-alone session or after the completion of another training session.

Planning a dynamic warm-up The following factors need to be considered when planning a dynamic warm-up: 1. The physical condition of the athletes ● This will determine the level of intensity at which the dynamic warm-up should start, the rate of progression of the intensity and the total workload of the session. ● It is important to bear in mind that it is a warm-up and not a conditioning or endurance session.

A survey of 6,000 marathon runners found that stretching was significantly associated with an increased injury rate

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