This is an excerpt from EuropeActive's Essentials for Fitness Instructors.
Warming Up for Resistance Training
The warm-up is an essential introductory part of the training session that helps participants prepare both mentally and physically for the training session (Siff 2004; Jeffreys 2008). Warm-up techniques can be broadly classified into two major categories: passive warm-ups and active warm-ups. Passive warm-ups involve raising the muscle temperature or core temperature by some external means. Various methods include hot showers or baths, saunas, diathermy and heating pads. Passive heating increases both muscle and core temperature without depleting energy substrates (Bishop 2003a). Meanwhile, active warm-ups involve exercise. They are likely to induce greater metabolic and cardiovascular changes than passive warm-up procedures, and they also potentially disrupt transient connective tissue bonds and improve the body's neuromuscular preparedness for the specific task ahead (Jeffreys 2008; Bishop 2003a).
A typical active warm-up for resistance training should involve two phases: general and specific. The purpose of a general warm-up is to increase the functional potential of the body as a whole, whereas the goal of the specific phase is to establish the optimal relationship between warm-up and the forthcoming resistance exercises (Siff 2004). A typical general warm-up can last 5 to 10 minutes (Ratamess 2012b). This first phase usually begins with light-intensity exercises such as jogging, cycling or easy stretching or active displacements. The intensity is increased progressively in order to lead participants towards the specific phase, which is aimed to optimise their preparation for the main part of the workout. However, for resistance exercises, a general warm-up does not always involve aerobic exercise such as cycling or jogging. Global callisthenic movements, easy stretching and dynamic flexibility movements are also appropriate.
A specific warm-up phase can last 8 to 12 minutes (Jeffreys 2008). Its structure varies greatly depending on the sport or activity. For resistance training, the specific part of the warm-up can involve several (four to six) dynamic exercises, which can be completed using bands or a medicine ball as required. Before commencing the main part of the workout, participants should perform one or two sets of a few repetitions (four to eight) with a light to moderate load of the principal multijoint exercise to be trained (Ratamess 2012b). It appears that a specific warm-up can provide further benefits in addition to those provided by a general, active warm-up, possibly by optimising the required neuromuscular activation for the main part of the workout (Bishop 2003b). The following list depicts examples of general and specific warm-ups for lower-body resistance training.
Examples of a Typical Lower-Body Resistance Training Warm-Up Involving Both General and Specific Phases.
● Five minutes of low-intensity aerobic exercises: jogging and three low-intensity stretching exercises (one leg rise for hamstring, forward lunge and seated toe touch).
● Medicine ball twist 1 x 20
● Medicine ball wood chops 1 x 10
● Straddled toe touch 2 x 5
● Dynamic quadriceps stretch 1 x 5
● Medicine ball squat 1 x 5 to 8
● Back squat using 50 percent of the load to be used during the main part of workout
Effects of the Warm-Up
The following list depicts the ways in which a proper warm-up positively affects performance (Bishop 2003a):
● Decreases resistance of muscles and joints
● Increases release of oxygen from haemoglobin and myoglobin
● Speeds up metabolic reactions
● Increases nerve conduction rate
● Increases thermoregulatory strain
● Increases blood flow to muscles
● Raises baseline oxygen consumption
● Enhances postactivation potentiation
● Psychologically prepares participant for main routine
The warm-up movements should speed up contraction and relaxation of both agonist and antagonist muscles, which improves strength, power, rate of force development and reaction time (Jeffreys 2008). Whilst the influence of warming up on injury prevention is still unclear (Bishop 2003a), some studies suggest that it prevents muscular or connective tissue injury (Olsen et al. 2004; Olsen et al. 2005). At the very least, a structured warm-up can enhance performance and may reduce injury potential (Ratamess 2012b). Currently no evidence suggests that a warm-up is detrimental to performance. Some evidence suggests that under certain circumstances, a low-volume and high-intensity resistance training exercise (>80 percent 1RM) warm-up increases neuromuscular activation and therefore increases the performance in explosive actions performed next (Tillin and Bishop 2009). It has also been hypothesised that warming up may have a number of psychological effects (Bishop 2003a).
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