Is a warm-up really necessary? What constitutes a "good" warm-up?
A warm-up activity serves two major purposes—to enhance performance and prevent injury. Consequently, a warm-up is both physical and mental.
Relaxed, sitting in your chair and reading this column produces a relatively low 15- to 20-percent of blood flow to your skeletal muscles. Most of the small blood vessels (capillaries) within those muscles are closed. After 10 to 12 minutes of total body exercise, blood flow to the skeletal muscles increases to some 70 to 75 percent and the capillaries open.
Along with more blood flow comes an increase in muscle temperature. This is good because the hemoglobin in your blood releases oxygen more readily at a higher temperature. More blood going to the muscles, along with more oxygen available to the working muscles, means better performance.
An increase in temperature also contributes to faster muscle contraction and relaxation. Nerve transmission and muscle metabolism is increased, so the muscles work more efficiently.
Scientific studies on linking warming up with injury prevention are difficult to administer. Few athletes want to go through a muscle stress test to see what it takes to tear a muscle.
Old studies on animal subjects determined that injuring a muscle that has gone through a warm-up process required more force and more muscle length than a muscle with no warm-up. This study is in line with the anecdotal data that acute muscle tears occur more often when the muscles are cold or not warmed up.
Part of a warm-up process includes getting your head ready for the upcoming activity. Mentally preparing for the upcoming workout, or event, is thought to improve technique, skill and coordination.
This mental warm-up also prepares you for the discomfort of a tough workout or race. If the mind is ready to endure discomfort, the body can produce a better performance. If the mind is unwilling to endure discomfort, physical performance will certainly be limited.
How Much Should I Warm Up?
There is no hard evidence as to how much warm-up is needed before a workout or a race. Most recommendations are in the 10- to 20-minute range.
A general recommendation for warming up is that it should be specific to the activity you're about to perform. This is easy for running, swimming, or biking; simply start at a lower intensity and gradually increase intensity as you progress through the warm up period.
For more complex exercise, like strength training, a dynamic warm-up of gradually increasing intensity and complexity of exercises is best. You'll be taking your muscles through the range of motion to come in the workout as well as preventing injuries by stretching muscles that are usually too tight, and activating muscles that are usually underused.
In order to perform at your best and minimise the risk of hurting yourself, take time for an adequate warm-up. Below is my Dynamic Warm-Up, which is best to do before a strength training workout.
Walking down and back 10 yds
Knee pull to chest
Walking lunges with rotation, then Backwards with an Overhead reach
Cross-over side step
Single leg reach In place
Prone Hip opener/chest opener