An Analysis of the Evidence Base Relating to the Role of Warm-Up and Stretching in Reduction of Injury Risk in Athletes

Pre-participation warm up and stretching in various forms is widely employed by athletes before both training and competition. Various potential benefits of warming up and stretching are proposed, including a reduction in the risk of injury. Our aim is to summarize the available literature, identify appropriate information resources, and to produce a reasoned evaluation of the available evidence. We concluded that every athlete, coach, or conditioning trainer must incorporate a warm-up protocol along with a stretching routine in an athlete’s training regimen. Introduction Athletes, coaches, trainers, physiotherapists, and physicians recommend warm-up, stretching and cool down exercises in an effort to both prevent injury and enhance performance [1]. Warmup increases blood flow to muscles, speed of nerve impulses, oxygen and energy substrate delivery, and oxygen release from hemoglobin and myoglobin [2]. It decreases both the activation energy for cellular reactions and muscle viscosity [2]. Warm-up is designed to increased muscle/tendon suppleness, increase body temperature, and enhance free, coordinated movement [3]. Warm-up techniques are classified in 3 major categories: (a) passive warm-up-increases temperature by some external means; (b) general warm-up increases temperature by nonspecific body movements; and (c) specific warm-up increases temperature using similar body parts that will be used in the subsequent, more strenuous activity [4,5]. Over the years, warm up protocols consisting of the abovementioned categories along with various structures (e.g. varied intensity, duration and recovery) have been used [6]. Muscular injury is one of the major problems facing today’s athletes, both recreational and professional, with injuries to skeletal muscle representing more than 30% of the injuries seen in sports medicine clinics [7]. There has been research done in the past both for and against the need for warm-up and stretching before sporting activity, and its role in injury prevention. Evidence for Warm-Up Studies have shown that the benefits of warm-up potentially reduce the risks of strain injury to the muscle [8]. Several programs that combine warm-up, strength training, balance training, stretching, controlled rehabilitation, information about the importance of disciplined play and the increased risk of injury, and correction and supervision by doctor(s) and physiotherapist(s) have demonstrated effectiveness in the prevention of knee and ankle injuries [9-11]. It has also been established that during preseason screening and rehabilitation following hamstring muscle injury, clinicians should consider the influence of hamstring strength, flexibility, warm-up, and fatigue on muscle performance [12]. A study using biomechanical support to assess the athletic practice of warming up prior to an exercise task to reduce the incidence of injury, inferred that physiologic warming is of benefit in preventing muscular injury by increasing the length and elasticity of the muscle-tendon unit [13]. DOI: 10.32474/OSMOAJ.2019.02.000144