Q: What causes muscle soreness and how is it best relieved?
A: There are two types of exercise-related
muscle soreness. Immediate muscle soreness
quickly dissipates and is the pain you feel
during, or immediately after, exercise.
Delayed muscle soreness signals a natural
adaptive process that the body initiates following
intense exercise. This type of muscle
soreness manifests itself 24 to 48 hours after
the exercise session and spontaneously
decreases after 72 hours.
Numerous studies have been conducted to
determine the cause of delayed muscle soreness.
The most current consensus attributes
this condition to microscopic tears in the
muscle and surrounding
connective tissue following
eccentric exercise. A muscle
contracts eccentrically
when it lengthens under
tension during exercise.
For example, during a
biceps curl, the biceps
muscle shortens during
the concentric lifting
phase and lengthens
during the eccentric lowering
phase. Eccentric
contractions also occur
during aerobic activity,
such as downhill running,
in which the
quadriceps muscle
repeatedly lengthens
against gravity to lower
the center of mass and
aid in shock absorption.
Exercisers who experience delayed muscle
soreness include conditioned individuals who
increase the intensity, frequency or duration
of their workouts, or participate in an activity
with which they are unfamiliar. Beginning
exercisers, or those who have undergone a
significant lapse in training, frequently experience
soreness when starting or re-engaging
in an exercise regimen.
Studies attempting to identify the best
methods to alleviate delayed muscle soreness
are almost as abundant as the number of
studies conducted to determine its cause.
Cryotherapy (the topical application of ice),
massage, stretching and the use of nonsteroidal,
anti-inflammatory drugs (NSAIDs),
among other less conventional approaches,
have been evaluated to determine if they can
prevent or effectively treat delayed muscle
soreness. To date, a therapy that consistently
relieves delayed muscle soreness has yet to
be identified. On the other hand, a few of the
aforementioned therapies may have a mild
positive impact if initiated immediately after
intense or unusual exercise.
Once an individual has experienced delayed
muscle soreness at a specific exercise intensity,
he or she shouldn't encounter that sensation
again until the intensity level is
increased. This is because
delayed muscle soreness has
been shown to produce a
rapid adaptation response,
which means that the muscles
adapt to a given exercise
intensity level. Until
(or unless) the exercise
intensity level is changed,
soreness won't occur. This
factor is the basis for the
most widely recommended
approach to preventing
delayed muscle soreness:
gradual progression and
conservative increases in
intensity, frequency and
duration. Preliminary light
exercise may prevent the
onset of soreness following a
heavy eccentric-exercise
workout. Beginners should exercise with
light weights, two to three times per week
for one to two months, then gradually
increase the intensity of their workouts.
Conditioned exercisers who want to try a
new workout or activity also should begin
gradually, taking care not to be overzealous
in how hard they exert themselves-
particularly until their bodies adapt to the
demands imposed upon them.
Source: Dr. Cedric X. Bryant, ACE's Chief Science Officer; ACE FitnessMatters, Jan/Feb 2007.
Sign up for ACE's FREE e-newsletter for fitness enthusiasts.