Many
of your members who are involved in strength training programs are
looking for new ways to maximize their strength gains. Studies conducted
at South Shore YMCA in Quincy, Mass., reveal an easy way for them to do
that, and suggest an unexpected benefit for your members who are
engaging in stretching exercises.
The
May 1999 issue of Fitness Management reported about two programs at
South Shore YMCA that showed the effects of combined stretching and
strength training on joint flexibility (strength, stretch and stamina,
pp.44-45). Not surprisingly, the results showed that participants who
performed both stretching and strength exercise improved their joint
flexibility more than those who performed strength training only.
South
Shore YMCA has now collected a considerable amount of data looking at
the other side of the coin. These studies examine the effects of
combined stretching and strength training on muscle strength. Thus far,
three separate studies with 155 subjects indicate a beneficial effect
from stretching exercise on strength development.
General Conditions
All of
the studies were conducted in South Shore's research room, with six
participants and two instructors per class. Participants were beginning
exercisers with an average age of 51 years. Subjects performed one set
of 12 strength exercise, eight to 12 repetitions each, two or three days
per week, for 10 weeks. The strength exercises include the leg
extension, leg curl, tricep extension, back extension, abdominal curl,
tricep extension, back extension, abdominal curl, neck flexion and neck
extension. Stretches were performed in either a distributed manner (one
static stretch following each strength exercise) or a consolidated
manner (six static stretches in sequence). All of the subjects were
assessed for hamstring strength by the 10 repetition maximum leg curl
test during the second and 10th week of each study.
Specific Studies
In the
first study, 15 previously untrained participants performed the 12
strength exercise without stretching. A similar group of 19 previously
untrained participants performed the same strength training program, but
followed each strength exercise with a 20 second static stretch for the
muscles just worked. The subjects who only performed strength exercises
increased their hamstring strength by 16.6 pounds, while the subjects
who performed both strength training and stretching increased their
hamstring strength by 20.5 pounds.
In the
second study, 21 beginning exercisers performed the 12 strength
exercises without stretching. A similar group of 21 beginning exercises
performed the same strength training program, but followed each strength
exercise with a 20 second static stretch for the muscle just worked. The
participants who only performed strength exercises improved their
hamstring strength by 16.3 pounds, and the subjects who performed both
strength training and stretching exercises improved their hamstring
strength by 18.6 pounds.
In the
third study, 32 previously sedentary subjects performed the 12 strength
exercises followed by a 20 second static stretch for the muscles just
worked (distributed stretching). A similar group of 47 previously
sedentary subjects performed the same strength-training program, but
performed a consolidated sequence of six 20 second static stretching
exercises during each workout. The subjects who did strength training
and distributed stretching gained 19.6 pounds in hamstring strength, and
the subjects who did strength training and consolidated stretching
gained 19.8 pounds in hamstring strength.
Combined Results
Based
on the findings from the first and second studies, the participants who
performed both strength training and stretching attained almost 19
percent more hamstring strength than the participants who performed
strength training only. Results from the third study showed the subjects
who did distributed stretching and the subjects who did consolidated
stretching achieved almost identical increases in hamstring strength.
Therefore, the data was combined for the 36 exercisers who performed
strength training plus stretching (distributed and consolidated). The
subjects who did not stretch experienced an average strength gain of
16.4 pounds, whereas the subjects who did stretch experienced an average
strength gain of 19.6 pounds. Although not a statistically significant
difference, the almost 20 percent greater strength gains experienced by
the participants who performed both strength and stretching exercise
seems to favor this training protocol. It is possible that stretching in
conjunction with resistance training may make muscles more responsive to
strength-building stimuli.
From a
practical perspective, combined strength and stretching exercises may
produce more improvements in joint flexibility and muscle strength than
strength training alone. When performed in a distributed manner between
strength exercises, stretching does not increase the total workout time,
and when performed in a consolidated manner during the training session,
it adds less than five minutes to the workout duration. For these
reasons, it may be worthwhile to try a combined strength and stretching
program with beginning exercise classes and selected clients.
Wayne
L. Westcott, Ph.D.
is fitness research director at the South Shore YMCA and
author of the new book
Strength Training Past 50.
More
Books from Dr. Westcott
CEC:
Current Strength Training Research
by Dr. Westcott
--------------------------------------------------------------------------------------------------------------------------------
