Updated: Aug 13, 2019
Getting up off the Laz-E-Boy or the office chair and starting a workout takes the body from a resting state to a working state. Warming up transitions the body from the low energy- and oxygen- demand condition of rest and prepares it for the requirements of exercise. The warm-up and cool-down segments of a workout are as important as the main set, fueling and hydration.
However, these sections are often cut short or even completely skipped over by the time-crunched athlete; or possibly planned inappropriately by an uninformed coach. A well-planned and well-executed warm-up sets the stage for an efficient workout that meets the training goals and needs of the athlete.
The initial stages of exercise occur in a state of oxygen deficit—a condition in which the skeletal muscle requires oxygen at a greater rate or amount than can be delivered by the cardio-pulmonary system. During warm-up, blood flow, oxygen consumption and macronutrient metabolism are altered to meet the increased requirements of skeletal muscle. However, until oxygen supply meets demand, this phase of exercise is, by definition, anaerobic—with anaerobic glycolysis (lactic acid-producing) serving as the predominant energy-providing system. Warm-up serves to transition the body through this largely anaerobic state into an aerobic condition that prepares muscles, joints, and the cardiovascular system for the workload of the main set.
Having A Plan
A well-planned warm-up specifically targets the primary energy system, working muscles, and movement patterns that drive the main set. An endurance (base) training session will usually be preceded by a moderate-intensity warm-up, which may or may not include a few high cadence intervals that predominantly stimulate motor neuron activity. Workouts at lactate threshold and above ideally warm up with an initial aerobic component followed by several focused, high intensity segments that raise the heart rate to or above lactate threshold. Altogether, warm-up stimulates the nervous, muscular and cardiovascular systems to work in the manner the training session will demand. Several physiological changes take place during the warm up stage, which serve the purpose of delivering oxygen and glycogen to working tissue, increasing energy production at the muscular level, dissipating heat, and removing metabolic by-products.
Cardiovascular: At rest, the majority of blood flow is through the gastrointestinal tract and the kidneys. With exercise, blood is redistributed to working skeletal muscles to meet the increased need for oxygen, nutrients, and removal of waste products. Blood pressure also changes during warm-up, which eases blood flow to and from the heart. Warm-up facilitates the changes in heart rate, vessel diameter and blood volume and flow necessary to fulfill the needs of exercise.
Pulmonary: Breathing at rest is fairly slow and shallow. Breathing rate increases and breaths become deeper and more forceful during exercise, bringing in more oxygen and expelling out carbon dioxide.
Metabolic: To meet the increased demand of skeletal muscle for glucose, energy-producing processes are ramped up during exercise. These processes take some time “to catch up” as the body transitions through the period of oxygen debt.
Neuromuscular: The nervous system also needs to be warmed up to facilitate proper muscular contraction and timing. Warm-up stimulates motor neurons (connections between the nervous system and the skeletal muscles) and optimizes the mind-muscle connection: the brain’s keen awareness and control of movement that elicits precisely coordinated muscular contractions. Drills performed in the warm-up stage enhance the mind-muscle connection, and should target the movements required to carry out the workout and address weaknesses in movement patterns. For example, running drills should stimulate the nervous system in the way a foot strikes, swimming drills should focus on catch and pull, hip rotation, etc.
Stretching has a similar roll in the warm-up process as drills, but also releases tension in muscles and tendons to prevent injury. Warm-up stretches should be dynamic in nature and in the same movement pattern as the overall activity. Research has shown that performance times and energy economy are improved with dynamic stretching over static or no stretching at all. Often, drills incorporate dynamic stretches, facilitating proper neuromuscular stimulation in the desired movement pattern.
Orthopedic: Bones and joints need to be warmed up too. Synovial fluid in the joints becomes more fluid as temperature increases, allowing for greater range of motion and ease in movement. Supportive tissues (i.e., cartilage, ligaments) around joints become more pliant, which also increases range of motion. Bones need the transition from rest to exercise to tolerate the increased mechanical impact, particularly that of running.
Cool-down has basically the opposite effect of warm-up—returning the body to its pre-exercise state. Temperature, heart rate and blood pressure decrease, oxygen consumption slows down, and metabolism eventually returns to resting levels. A gradual cool-down facilitates this transition without an abrupt “stop” to the body systems. In particular, vasodilation (increased blood vessel diameter) occurs during exercise to facilitate blood flow throughout the body. This is gradually reversed during cool down, which results in blood being reallocated from skeletal muscle back to the GI tract. Abruptly stopping exercise—particularly high intensity work—may lead to blood pooling in vasodilated peripheral vessels, which in turn causes post-exercise dizziness and/or loss of consciousness experienced by some athletes who skip over the cool-down.
Stretching and drills during cool-down help stimulate the mind-muscle connection through practicing good form and skills when the muscles are fatigued. This reinforces proper movement patterns at a time when the body resists control and wants to revert back to “lazy” motion. This can go a long way to the development of efficient muscle coordination and prevention of injury. Finally, low-intensity aerobic movement, foam rolling and dynamic stretching all help to flush out metabolic by-products consequential to exercise.
Physiological changes that occur during the warm-up and cool-down sections are essential to the preparation for and recovery from a good workout. They serve a facilitative and protective purpose in the overall adaptation of the body to exercise. These phases of a training session are important components of a workout and should be completed with the same attention as the main set.
Check back for a follow up post on Dynamic Stretching……
Written by 212˚ In Motion Co-Founder Lori Cooper….