Chapter 14 of the Essentials of Strength Training and Conditioning covers the warm up before exercise as well as training for flexibility.

Warm-Up and Flexibility Training

• The warm-up is designed to get the athlete ready for the upcoming training session or competition. Flexibility aims to increase the range of motion around a joint.These two areas are often linked but, it's important to differentiate them.

Warm-Up

• A warm-up has several mental and physical benefits and is best done actively instead of passively. Some of these benefits may include things like improved rate of force development and reaction time, improved strength and power and increased blood flow to active muscles.
• General Warm-up - movements to get the athlete's heart rate, deep muscle temperature, blood flow, respiration rate, sweat rate, and decrease viscosity of joint fluids. May consist of 5 minutes of activities like jogging or skipping.
• Specific Warm-up - movements similar to the athlete's sport.
• Training warm-ups and competition warm-ups need to be designed specifically with the idea of the activity following the warm-up.
• Since warm-ups may take 10-20 minutes, they should be thought of as integral part of training and can contribute greatly to an athlete's overall development.
• Raise, Activate and Mobilize, and Potentiate (RAMP) - a process of warming up that has been adopted by many professionals. The first phase involves activities that raise skill and the same physiological parameters as the general warm-up using movement patterns like the sport. The second phase involves using key movement patterns that will be used in the activity like squat patterns. The third phase involves using sports specific activities that progress until intensity matches that of the subsequent competition or training session.
• Potentiation - in the context of this chapter it means to increase intensity of the warm up until it meets that of the activity you are about to partake in. In a general sense to potentiate is to increase the effect of something.

Flexibility

• Range of Motion (ROM) - The degree of movement that occurs at a joint.
• Flexibility - a measure of ROM. Has both a static and dynamic component.
• Static Flexibility - the passive range of motion about a joint. External forces like gravity or a partner provide the stretch.
• Dynamic Flexibility - the active range of motion about a joint. Requires muscular action and is generally greater than static ROM.
• Mobility - the dynamic ability to move about a joint, coordinate balance, postural control, and control force through range of motion.
• The goal of flexibility training is to optimize flexibility in relation to the specific sport or activity being undertaken. The most flexible athlete is not always the best.
• Ball-and-Socket Joints - joints with the greatest possible range of motion. Move in all anatomical planes.
• Ellipsoidal Joint - a joint that is received into an elliptical cavity and allows movement in two planes.
• Hinge Joint - a joint formed between two bones that allow movement in one plane.
• Women and younger people are often more flexible than males and older people.
• Fibrosis - a process commonly experienced by older individuals where fibrous connective tissue replaces degenerating muscle fibers.
• Elasticity - the ability to return to the normal length after a passive stretch.
• Plasticity - the tendency to assume a new and greater length after a passive stretch.
• Stretch tolerance is the ability to tolerate the discomfort of stretching. This can potentially lead to tolerating greater stretch loads and allow improved flexibility.
• The improvements in range of motion from acute bouts of stretching are transient. In order for long lasting effects to occur, a dedicated flexibility program is required.
• Stretching twice per week for five weeks has been shown to improve flexibility. It is accepted that stretches should be held for 15-30 seconds with diminishing returns beyond 30 seconds.
• Stretching should be performed following practice, competitions and as a separate session if increased flexibility is a requirement.
• Muscle Spindles - run parallel to other muscle fibers and detect changes in muscle length.
• Golgi Tendon Organs (GTOs) - receptors located near joints that detect muscular tension.
• Stretch Reflex - a muscular contraction that is responsible for automatic regulation of skeletal muscle length. Will limit the range of motion if stretching.
• Mechanoreceptor - a receptor neuron that responds to mechanical pressure changes.
• Autogenic Inhibition - a sudden relaxation in the same muscle that is experiencing increased tension.
• Reciprocal Inhibition - muscle on one side of a joint relaxing in order to allow muscles on the opposite side to contract.

Types of Stretching

• Active Stretch - when the person stretching applies force to accomplish a stretch.
• Passive Stretch - when a partner or an external force like a machine applies force to accomplish a stretch.
• Static Stretch - a slow and constant stretch held for 15-30 seconds.
• Ballistic Stretch - using a bouncing active muscular effort to stretch. Has been shown to be just as effective as passive stretching but, care must be taken to ensure there is not injury.
• Dynamic Stretch - a type of stretch that uses a sport specific and sport generic movement to prepare the body for activity. Avoids bouncing. A good way to warm up but, not as beneficial to flexibility as static or PNF stretching.
• Mobility Drills - another term for dynamic stretching.
• Proprioceptive Neuromuscular Facilitation (PNF) - an advanced method of stretching that requires three specific muscle actions to facilitate a passive stretch. Contraction, hold and relax. Often needs a partner.
• Agonist Contraction - A concentric muscle action of an agonist muscle
• Hold-Relax - PNF stretching technique. A passive pre-stretch, contraction and isometric hold followed by a passive stretch.
• Contract-Relax - PNF stretching technique. A passive pre-stretch and concentric contraction through full ROM followed by a passive stretch. Preferred over Hold-Relax technique.
• Hold-Relax with Agonist Contraction - PNF stretching technique. A passive pre-stretch, contraction and isometric hold followed by a passive stretch and contraction of agonist to increase stretch force. The most effective PNF stretch.