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Wizard
Five
Warm up, Stretch and Flexibility
The Debate: Part I
You already know that warming up before play is important. You
may perform a series of exercises with the objective of reducing
injuries and increasing performance.
However, there is a body of current research regarding
flexibility and stretching with some surprising results:
- greater static flexibility does not always decrease the risk
of muscular injury;
- flexibility and stretching may be unrelated to injury risk;
- stretching has minimal effect of the stiffness of muscle,
decreases muscular performance, and modifies the energy recovery
of stretched muscle.
If you are like me, you might have said "WOW, that's the
opposite of what I thought." For myself, I wanted to get clear
definitions of warm up versus flexibility versus stretching and how
this research impacts tennis players.
I went to two experts for the answers: Dr. Marc Safran, director
of Sports Medicine at the University of California, San Francisco,
orthopaedic surgeon and vice president of the Society for Tennis
Medicine and Science and Dr. Duane Knudson, professor of exercise
science at California State University, Chico. Dr. Knudson is a
biomechanist as well as a member of the USTA sport science
committee, and one of the individuals conducting this research.
Dr. Safran told me: "The warm up is an important means to prevent
injuries and should be performed before every workout. The gradual
increase of the body temperature through the warm up prepares the
body for the hard work it has soon to perform. The elevated
temperature increases muscle blood flow, mechanical efficiency of
contraction, and the speed of nerve impulse, leading to more rapid
and forceful muscle contractions. Also, the increase in temperature
results in a decreased viscosity of muscle and a greater force and
length of stretch necessary to tear a muscle. Thus, a proper warm up
may reduce the incidence and likelihood of musculoskeletal injuries
and lead to improved performance."
As well, Dr. Knudson has noted, "Most warm-ups should begin with
general body movements of gradually increasing intensity, focusing
on the muscles and joints to be used in training or competition...
The American College of Sports Medicine recommends 5 to 10 minutes
of calisthenic-type exercises and 5 to 10 minutes of progressive
aerobic activity in warm-up. For example, tennis players may perform
5 minutes of light jogging, followed by the traditional 5-minute
warm-up of groundstrokes and serves prior to a match... Warm-up may
also decrease the occurrence of dangerous cardiac responses from
sudden strenuous exercise in some people."
Good reasons to warm up! How does the recent research on
stretching and flexibility fit into this? Knudson notes, "static
stretching is not recommended during warm-up routines."
What's the difference then? Why wouldn't you want to stretch? Do
most experts agree on this? What's the relationship between
stretching, flexibility, warm-up, performance and injury?
Let's go through some definitions:
Warm-up: (Knudson) Warm-up consists of active or passive
warming of body tissues in preparation for physical activity.
Active warm-up: (Knudson) Active warm-up consists of low
intensity movements that are effective in warming tissue and
producing a variety of improvements in physiological function.
Passive warm-up: (Knudson) Passive warm-up includes
external heat sources like heating pads, whirlpools, or ultrasound.
Static stretching: (Safran) Static stretching is the most
common form of stretching. This is where the muscle is slowly and
gently stretched to the point of slight muscle discomfort and then
held for a period of time (usually 10 - 20 seconds). This type of
stretching is simple technique, has a low injury risk and does not
require a partner.
Ballistic stretching: (Safran) In a ballistic stretch the
muscle is stretched with repetitive bouncing motions. These
exercises are generally not advised due to an increased risk of
injury.
Active and passive stretching: (Safran) Combined active
and passive stretching involves contraction of the muscle (without
moving the joint), relaxation and static stretching of the muscle,
in various combinations and orders. These techniques are capable of
producing the greatest improvements in flexibility; however, they
usually require the help of a partner. (These techniques may be
useful for sports which require superior flexibility, such as
gymnastics, but are rarely necessary in tennis.)
Flexibility: Flexibility is a property of body tissues
which determines the range of motion achievable without injury at a
joint or group of joints.
The issue then appears to be that recent studies question the
correlation between stretching, flexibility, injury reduction and
performance enhancement.
Next month we'll look at the controversy and help determine,
"What's a tennis player to do?"
My thanks to my colleagues Dr. Marc Safran and Dr. Duane Knudson
for their assistance in this interesting area of research.
I also wanted to thank all of you who responded to last month's "Can
We Count" column. There were some great comments and I will be
contacting some of you to ask if I can use your comments in a
summary on the subject.
Until Next Month ... Jani
You can find more
articles like this to help your tennis game by going to
www.tennisserver.com .
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