Sports Medicine: Just the Facts

a valuable aid in prescribing exercise for individuals

who have difficulty with HR palpation, and in cases

where the HR response to exercise may have been

altered owing to a change in medication. The average

RPE range associated with physiologic adaptation to

exercise is 12–16 (“somewhat hard” to “hard”) on the

category Borg scale. One should suit the RPE to the

individual on a specific mode of exercise and not

expect an exact matching of the RPE to a %HRmax or

%HRR. It should be used only as a guideline in set-

ting the exercise intensity (Franklin et al, 2000b;

Pollock et al, 1998).

• Finally, the appropriate exercise intensity is one that is
  safe and compatible with a long-term active lifestyle
  for that individual and achieves the desired outcome
  given the time constraints of the exercise session.

Duration

• The ACSM recommends 20–60 min of continuous
  aerobic activity.
  •However, deconditioned individuals may benefit from
  multiple, short-duration exercise sessions <10 min
  with frequent interspersed rest periods.


• An inverse relationship exists between the inten-
  sity and duration of training. There may be greater
  musculoskeletal and cardiovascular risk with exer-
  cise performed at high intensities for short dura-
  tions as compared with lower intensity exercise
  for a longer duration (Franklin et al, 2000b; Pollock
  et al,1998).

Frequency

• The ACSM recommends that aerobic exercise be per-
  formed 3–5 days per week for most individuals.


• Less conditioned people may benefit from lower
  intensity, shorter duration exercise performed at
  higher frequencies per day and/or per week (Franklin
  et al, 2000b).

Progression (Overload)

• The rate of progression depends on health/fitness
  status, individual goals, and compliance rate.


• Frequency, intensity, and/or duration can be increased
  to provide overload.


• The goal for most healthy individuals is 30 min, 3–4
  days per week at 85% HRR (Franklin et al, 2000b).

MUSCULARSTRENGTH ANDENDURANCETRAINING

• Overload and specificity are precepts of resistance train-
  ing. Overloadoccurs when a greater than normal phys-
  ical demand is placed on muscles or muscle groups.
  Muscular strength and endurance are developed by
  increasing the resistance to movement or the frequency
  or duration of activity to levels above those normally
  experienced. A training intensity of approximately
  40–60% of one repetition maximum appears to be

sufficient for the development of muscular strength in

most normally active individuals (Franklin et al, 2000b;

Bryant and Peterson, 2001).

• Specificityrelates to the nature of changes (structural
  and functional, systemic and local) that occur in an
  individual as a result of training. These adaptations
  are specific and occur only in the overloaded muscle
  groups or muscles (Durstine and Davis, 2001).

The ACSM Provides the Following Guidelines

for Resistance Training:

• A 5–10-min warm-up period consisting of aerobic
  activity or a light set (50–75% of training weight) of the
  specific resistance exercise should precede the resist-
  ance exercise program. The goal is to develop total
  body strength and endurance in a time-efficient manner
  (Franklin et al, 2000b; Bryant and Peterson, 2001).
  1.Mode:The prescription should include a minimum
  of 8 to 10 separate exercises that target major muscle
  groups (arms, shoulder, chest, abdomen, back, hips,
  and legs). Free weights and weight machines are
  commonly used; however, springs, surgical or rubber
  tubing, and electronic devices are also used for
  resistance training (Franklin et al, 2000b).
  2.Intensity/Duration:Perform a minimum of one set
  of 8 to 12 repetition of each of the exercises to the
  point of volitional fatigue. Volitional fatigue refers
  to the inability to move a resistance through the
  appropriate range of motion with proper mechani-
  cal form. A set of 10 to 15 repetitions is recom-
  mended for developing muscular endurance and
  for those who are older or frailer (Franklin et al,
  2000b).
  3.Frequency:Perform these exercises 2 to 3 days per
  week, usually with a day of rest in between
  (Franklin et al, 2000b).
  4.Progression:Resistance may be increased when
  12 repetitions can be completed with good tech-
  nique (Franklin et al, 2000b).
  5. Additional Recommendations
  a. Perform every exercise through a full range of
  motion using proper technique and in a con-
  trolled manner including the lifting (concentric
  phase) and lowering (eccentric phase).
  b.Maintain a normal breathing pattern and avoid
  breath holding (Valsalva).
  c. Exercise with a partner when possible to pro-
  vide feedback, assistance, and motivation
  (Bryant and Peterson, 2001).

MUSCULOSKELETALFLEXIBILITYTRAINING

Stretching Techniques

•Static stretching:Static stretching involves slowly

stretching a muscle to the point of mild discomfort

80 SECTION 1 • GENERAL CONSIDERATIONS IN SPORTS MEDICINE