Age and Exercise
     A.   General
          1.   performance
               a.   peaks at about 13-30 and the drops off
                    afterwards
               b.   both AGE and DISUSE attribute 
          2.   speed of movement
               a.   peaks early , 20 yrs
          3.   endurance
               a.   peaks later , 30
          4.   re-establishing homeostasis
               a.   takes longer with age
     B.   Specifics
          1.   Muscle functions
               a.   Strength 
                    (1)  reaches max at about 25 - early 30's
                    (2)  declines fairly slowly with age
                         (a)  activities help to keep strength
               b.   Cellular changes
                    (1)  loss of myofibrils
                         (a)  more pronounced in the FT
                    (2)  lome loss of muscle cells
                         (a)  also more prominent in the FT
                    (3)  therefore, performance in the FT will
                         decrease more rapidly than ST
                         (a)  this is why FT athletes are younger
                    (4)  there is also a greater discrepency at a
                         higher velocity than at a low velocity
                    (5)  decrease in the amoumnt of mitochondria
                         (a)  follows the same pattern as the FT
                              fibers
                         (b)  training increases both the amount
                              and the size of mitochondria in the
                              young and the old
                         (c)  however, with age
                              i)   there is less increase in
                                   number and more increase in
                                   size
                              ii)  muscle tissues become less
                                   exiteable
                              iii) recovery / refractory period is
                                   slower
                              iv)  effiency decreases, but less
                                   and less with age
               c.   changes in BMR
                    (1)  BMR decreases
                    (2)  changes in capacity for muscle
                         hypertrophy
                         (a)  cannot happen as much
                    (3)  with weight training
                         (a)  hypertrophy occurs much faster in
                              youths, because:
                         (b)  when older, there is not as much
                              hypertrophy but there is lots of
                              strength gains
                              i)   may be due to CNS changes
                              ii)  differences between males and
                                   females in hypertrophy may be
                                   due to CNS changes also
                         (c)  decreased amount of testosterone
                         (d)  decreased amount of FT fibers
               d.   Cardiovascular system
                    (1)  HRmax decreases with age
                         (a)  220-age = Std.Dev of +/- 10
                              i)   with age the SD increases
                              ii)  may tend to lead to
                                   underestimate HR max 
                         (b)  amount of activity may influence
                    (2)  Cardiac Output decreases 
                         (a)  1% per year after maturity
                    (3)  Coranary arteries change
                         (a)  Lumen (opening)decreases
                    (4)  BP increases
                         (a)  loss of elasticity of arterial wall
                         (b)  artherschlorosis
               e.   Pulmonery Function
                    (1)  decrease of compliance of the chest and
                         arterial wall
                         (a)  rib bones become more hard and
                              brittle
                    (2)  leads to decreased VC
                    (3)  and increased VC
                    (4)  also, increases the work of ventilation
                         (a)  20% of the decreases in Ve are due
                              to ventilatory compliance
                    (5)  decreased Ve
                         (a)  25% by age 65
                         (b)  possibly 50% by age 75
                         (c)  causes
                              i)   increased dead space compared
                                   to lung volume
                              ii)  mismatch between ventilation
                                   and perfusion
                                   a)   blood does not go to the
                                        correct part of the
                                        alveoli that contain the
                                        O2
                              iii) reduction in pulmonery
                                   diffusion capacity
                                   a)   alveoli and capillary
                                        membranes
               f.   VO2max
                    (1)  if expressed in l/min, there is big
                         changes throughout life
                    (2)  if in ml/kg*min, not much change till
                         adulthood, then it starts to drop off
                         (a)  probably due to CO
                         (b)  possibly Ve also
                         (c)  lean body mass changes affects also
                    (3)  can increase VO2max with training
                         (a)  if sedentary
                              i)   20% increase in 6 months
                         (b)  with age it takes longer
               g.   CNS
                    (1)  reaction time
                         (a)  increases with age
                              i)   due to the decreased rate of
                                   CNS processing
                    (2)  speed of movement
                         (a)  decreases with age
                         (b)  may be due to the FT fiber decreases
               h.   Body Structure
                    (1)  Body comp
                         (a)  increases in the amount of fat till
                              middle age
                         (b)  may see fat drop off after that
                    (2)  Height
                         (a)  ?? posibly decreases of 1/2" per
                              decade after age 30
                              i)   compression of intervertebral
                                   disks
                                   a)   more prominent in people
                                        working in vibration
                                        situations - farmers
                              ii)  osteoporosis
                                   a)   changes the shape of the
                                        vertebra as there is a
                                        deterioration of the
                                        spongy bone on the front
                                        of the vertebra and not
                                        the back
                                   b)   causes the spine to round
                                        forward
                                   c)   Kyphosis = head and neck
                                   d)   Ca++ RDA's
                                        e)   1000 /day pre-
                                             menopausal
                                        f)   1500 / day post -
                                             men.
               i.   Flexibility
                    (1)  decreases with age
                    (2)  due to
                         (a)  deterioration of molecular structure
                              of collagen (foamy CT) and elastic
                              tissue
                         (b)  development of osteoarthritis
                              i)   growths on the bone that cause
                                   pain as one moves through the
                                   maximum range of motion
                              ii)  causes one not to mave as far
                              iii) don't keep the CT elastic