Dynamic Stretching (NASM): Benefits, Examples, and How to Incorporate It

What is Dynamic Stretching (NASM)?

Dynamic stretching, as advocated by the National Academy of Sports Medicine (NASM), involves actively moving a limb through its full range of motion to prepare the body for physical activity, enhancing tissue extensibility and neuromuscular efficiency.

Understanding Dynamic Stretching

Dynamic stretching is a form of active movement that takes joints and muscles through their full range of motion. Unlike static stretching, where a position is held for an extended period, dynamic stretches involve continuous, controlled movements. The primary goal of dynamic stretching is to prepare the body for the physical demands of exercise, sport, or daily activity by increasing core body temperature, activating the nervous system, improving joint mobility, and enhancing the extensibility of soft tissues.

Dynamic Stretching within the NASM OPT Model

NASM integrates dynamic stretching into its comprehensive Optimum Performance Training (OPT) model, specifically within the Functional Flexibility component. The OPT model emphasizes a progressive approach to training, including flexibility, to optimize performance and reduce injury risk.

• The Flexibility Continuum: NASM outlines a flexibility continuum:
  • Corrective Flexibility (Phase 1: Stabilization Endurance): Focuses on improving muscle imbalances and altered joint mechanics through techniques like Self-Myofascial Release (SMR) and static stretching.
  • Active Flexibility (Phases 2-4: Strength Endurance, Hypertrophy, Max Strength): Utilizes SMR and active-isolated stretching to improve soft tissue extensibility and neuromuscular control.
  • Functional Flexibility (Phase 5: Power): Incorporates SMR and dynamic stretching. This phase is designed to prepare the body for integrated, multi-planar movements at higher speeds and intensities, making dynamic stretching a crucial component of the warm-up for advanced training.

Within the NASM framework, dynamic stretching is considered an essential part of a comprehensive warm-up, particularly before activities that require speed, power, agility, and a wide range of motion.

Physiological Benefits and Mechanisms

The scientific rationale behind dynamic stretching is rooted in its ability to prime the body for activity:

• Increased Core Body Temperature: Movement generates heat, which makes muscles and connective tissues more pliable and less prone to injury.
• Enhanced Neuromuscular Efficiency: Dynamic movements stimulate the nervous system, improving the communication pathways between the brain and muscles. This leads to better coordination, balance, and reaction time.
• Improved Range of Motion (ROM): By actively moving through a full range of motion, dynamic stretches can temporarily increase joint ROM without the potential negative impact on power output sometimes associated with prolonged static stretching performed pre-activity.
• Stimulation of Proprioceptors: These sensory receptors (e.g., muscle spindles, Golgi tendon organs) provide feedback to the central nervous system about body position and movement, improving body awareness and control.
• Increased Blood Flow: Active movement boosts circulation, delivering oxygen and nutrients to working muscles and facilitating waste removal.

When and How to Implement Dynamic Stretches

Dynamic stretches should always be performed before exercise, sports, or any significant physical activity, as part of a structured warm-up.

• Specificity: The chosen dynamic stretches should mimic the movements and energy systems of the activity to be performed. For example, leg swings for running, or arm circles for throwing.
• Controlled Motion: Movements should be smooth and controlled, avoiding ballistic (bouncing) actions that can increase injury risk.
• Progression: Start with smaller ranges of motion and gradually increase as the body warms up.
• Sets and Repetitions: Typically, 1 set of 10-15 repetitions for each movement, or performing each movement for 30-60 seconds, is sufficient.
• Order of Warm-up: Dynamic stretching usually follows a light cardiovascular activity (e.g., 5-10 minutes of jogging) to further raise core body temperature.

Common Examples of Dynamic Stretches

Incorporating a variety of movements that target major muscle groups and joints is key.

• Lower Body:
  • Leg Swings: Forward/backward and side-to-side to mobilize the hips.
  • Walking Lunges: With or without a torso twist to engage the core and hips.
  • High Knees: To warm up the hip flexors and mimic running mechanics.
  • Butt Kicks: To warm up the hamstrings and quadriceps.
  • World's Greatest Stretch: A multi-segmental movement involving a lunge, hip mobility, and thoracic rotation.
• Upper Body/Torso:
  • Arm Circles: Forward and backward to mobilize the shoulder joint.
  • Torso Twists: Gentle rotation of the spine.
  • Cat-Cow: A spinal mobilization exercise.
  • Inchworms: A full-body movement that stretches the hamstrings and activates the core and shoulders.

Dynamic vs. Static Stretching: The NASM Distinction

NASM clearly differentiates between dynamic and static stretching based on their purpose and timing:

• Dynamic Stretching:
  • Nature: Active, movement-based.
  • Timing: Performed before activity as part of a warm-up.
  • Goal: To prepare the body for movement, increase performance, and reduce injury risk during activity.
• Static Stretching:
  • Nature: Passive, held for a period (typically 20-30 seconds).
  • Timing: Performed after activity (cool-down) or as a separate session for long-term flexibility improvements.
  • Goal: To increase overall range of motion, improve long-term flexibility, and aid in muscle recovery. Prolonged static stretching before activity can temporarily decrease power output.

NASM recommends dynamic stretching for warm-ups (functional flexibility) and advocates for static stretching (and SMR) primarily for cool-downs and to address specific muscle imbalances as part of corrective flexibility.

Conclusion

Dynamic stretching, as defined and emphasized by NASM, is a cornerstone of effective warm-up protocols. By incorporating controlled, active movements that prepare the body for the specific demands of exercise, individuals can significantly enhance their performance, improve joint mobility, and reduce the risk of injury. Understanding its physiological benefits and proper application within the NASM OPT model empowers fitness professionals and enthusiasts to optimize their training and achieve their fitness goals safely and effectively.