tion in strengthening activities (such as RESISTANCE
EXERCISE), FITNESS LEVEL, FLEXIBILITY, and the range
of motion of the joints. Additional factors that
may become important for competitive athletes
include individual genetic characteristics and
physical structure, which influence the manner
and rate at which muscle fibers contract, relax,
and recover. Rest is an important element of
resistance exercise or strength training. Most regi-
mens alter body regions, such as upper body one
day and lower body the next day or rotate
strengthening activities with endurance activities.
Strength exercises are particularly important
for adults over age 65, helping sustain a high per-
centage of LEAN MUSCLE MASSas well as to maintain
BONE DENSITYand BONEstrength. Lean muscle mass
naturally declines with advancing age, with fat
cells replacing muscle cells. Activity that chal-
lenges the muscles encourages conversion of fat to
muscle, improving lean muscle mass. Changes in
HORMONElevels in the body, particularly in women
after MENOPAUSE, cause changes in the amounts of
calcium in the BLOODcirculation that regulate how
much calcium enters and leaves the bones. Regu-
lar muscle activity improves calcium distribution
mechanisms, keeping more calcium in the bones.
See also AEROBIC EXERCISE; CONDITIONING; DISABIL-
ITY AND EXERCISE; PHYSICAL ACTIVITY RECOMMENDA-
TIONS; WEIGHT LOSS AND WEIGHT MANAGEMENT.
training The process of improving the body’s FIT-
NESS LEVELthrough targeted, repetitious physical
activity that has specific goals. Training also may
refer to the preparation necessary for an event
such as a race or a circumstance such as a sports
season. The premise of training is to gradually
escalate the challenge to the muscles for improved
STRENGTH and FLEXIBILITYand to increase AEROBIC
CAPACITYfor improved ENDURANCE.
Building a Training Regimen
A typical training regimen emphasizes preparation
for the dominant activity, for example running or
playing tennis. Flexibility, strength, and AEROBIC
EXERCISEtarget measurable improvement in the
activity’s performance. A runner may strive for a
faster pace, a tennis player may aim for a stronger
serve or backhand. Short, focused sessions are
most effective at the onset of a training regimen,
with incremental increases in intensity and dura-
tion as ability and fitness improve. It is important
to have specific, stepped goals and methods for
measuring progress toward them. Goals should
accommodate competitive as well as personal fac-
tors. A new runner might establish first level goals
of achieving a 12-minute mile and completing a
5-K race or organized running event, for example.
Proper nutrition and HYDRATION are essential as
well.
Most people benefit from the advice of experts
in their chosen activities, such as by taking classes,
joining clubs, or researching training methods in
books and on the Internet. Such advice can jump-
start a training regimen, getting to the core of
methods with proven effectiveness as well as
reducing the likelihood of injury. The most com-
mon injuries that occur early in a training regi-
men are those related to doing too much too fast
or to inadequate WARMUP. Such injuries are gener-
ally preventable through proper technique and
include MUSCLE soreness, blisters, CHAFING, and
SPRAINS AND STRAINS.TIPS FOR SUCCESSFUL PHYSICAL TRAINING- When starting a training regimen, begin slowly and aim for
steady improvement. - Establish specific goals and methods for measuring progress
toward them. - Start and end every training session with WARMUPexercises
and stretches. - Vary activities to let the body recover, keep interest, and
improve overall fitness. - Increase intensity and duration in increments as ability and
fitness improve. - Eat nutritiously and drink water often.
- Enjoy the chosen activities.
Maintaining a Training Regimen
Once a person reaches his or her desired training
level, it is important to continue varying activities
and intensity levels to provide a mix of challenges
for the body. Some people alternate types of activ-
ities each day, for example doing an aerobic activ-
ity one day and weight training or resistance
training the next. Other people prefer to mix it up
within each exercise session.
It is also important to let the body rest. Com-
petitive athletes often incorporate “time off” fromtraining 233