We   are   generally   less   active   now   than   in   the   past.   This   is   because   newer technologies   are   making   our   lives   easier   and   we   are   getting   lazier.      We   move around    less    and    burn    off    less    energy    than    people    in    the    past.    Research suggests   that   many   among   us   spend   more   than   seven   hours   a   day   sitting   and in    over    65s,    spend    more    than    10    hours    sitting.    We    have    all    been    told repeatedly   that   to   stay   healthy   we   must   exercise   regularly.   Lack   of   exercise   is associated     with     numerous     health     conditions,     including     obesity,     heart disease, stroke, cancer, diabetes and osteoporosis. Most   of   us   know   how   beneficial   exercise   is   for   our   health.   However,   it   is surprising   how   little   many   of   us   know   about   the   dangers   of   being   unfit.   The number   of   overweight   people   is   growing   alarmingly   fast   all   over   the   world. Department   of   Health   in   UK   describes   inactivity   as   a   “silent   killer”.   So   act now if you are not already at it. How    does    exercise    help?        To    improve    health    through    exercise    it    is necessary   to   make   your   heart   beat   faster.   When   it   beats   faster   it   forces   more blood   thereby   oxygen   to   every   organ   in   the   body.   This   is   one   of   the   reasons   why   the   whole   body   benefits   by   exercise.   There is however a maximum safe rate at which a normal heart can beat. This will depend on your age. We will come to this later.    Muscles   and   Heart:    When   you   exercise   regularly,   you   strengthen   the   muscles   that   do   the   work.   To   supply   the   muscles with   enough   oxygen   during   the   work   out,   the   heart   has   to   work   faster.   This   increased   work   load   (within   safe   limits)   will strengthen   the   heart   muscles.   Keeping   the   heart   healthy   is   the   key   to   the   overall   benefit   you   gain   through   exercise. Unfortunately, when you stop exercising all the benefit gained is slowly lost. Kidney:   The   increased   blood   flow   through   the   kidney   helps   to   get   rid   of   unwanted   chemicals   (urea,   ammonia,   uric   acid ,    etc) that are by-products of digested foods. Brain:   Irrespective   of   age   increased   blood   flow   through   the   brain   improves   memory   and   learning   function.   It   will   also   delay the onset of Alzheimer's in people who are prone to it. Bone:   Regular   exercise   helps   maintain   stronger   muscles   and   bones   particularly   in   the   elderly.   Total   inactivity   results   in   weak muscles and loss of minerals from the bone resulting in osteoporosis. Immune System:   With regular exercise you generally become more resistant to infections. Endocrine   System:    Exercise   has   a   beneficial   effect   on   the   glands   that   produce   different   hormones.   One   of   them   relates   to diabetes   where   it   becomes   easier   to   control   blood   sugar   level.   People   with   type   2   diabetes   have   too   much   glucose   in   their blood,   either   because   their   body   doesn’t   produce   enough   insulin   to   process   it,   or   because   their   body   is   resistant   to   insulin.     Exercise   helps   the   muscles   to   use   glucose   without   insulin.   What   this   means   is   that   through   exercise   the   blood   glucose   level will go down whether you are insulin resistant or there is not enough insulin being produced. Type   of   Exercise:      As   mentioned   earlier,   the   aim   of   any   exercise   is   to   increase   the   heart rate   to   its   optimum   level.   You   can   do   this   by   a   variety   of   activity   like   jogging,   cycling, swimming   or   brisk   walking.   Depending   on   your   age   and   your   physical   fitness,   you   decide on   the   type   of   exercise   to   do.   If   you   have   never   exercised   before   it   is   best   to   start   with simple walking, extending it slowly to 20 minutes a day. To   stay   healthy,   adults   should   aim   to   achieve   at   least   3   hours   of   moderate   to   vigorous physical   activity   every   week.   You'll   get   the   most   from   your   workouts   if   you're   exercising   at the proper exercise intensity for your health and fitness goals. Research   has   shown   that   interval   training,   ie   higher   intensity   exercise   done   for   short   bouts (1   minute)   interspersed   throughout   your   workout,   is   well   tolerated,   even   by   those   with certain    cardiac    conditions.    This    type    of    workout    is    very    effective    at    increasing    your cardiovascular fitness. Irrespective   of   the   type   of   exercise   you   indulge   in,   never   overdo   them.   If   at   the   end   of   the session   you   are   very   tired   or   exhausted,   you   have   exceeded   the   optimum   level   and   that will cause more harm than good. Simple Tests to check health of your heart before you start exercising: Most   heart   problems   start   after   the   age   of   55.   If   you   are   past   55,   there   are   some   simple   tests   that   you   can   do,   to   determine if your heart is healthy. 1 . Check   your   pulse   when   you   are   sitting   calmly   and   resting.   It   should   be   anything   between   60   to   75   per   minute.   Next climb   a   flight   of   stairs   or   walk   for   two   minutes   and   check   your   pulse.   It   should   have   increased   by   at   least   10%.   If   it   has not increased, you should see a doctor. 2 . Check   your   pulse   before   you   start   any   activity   (brisk   walking,   going   up   the   stairs,   running   etc).   Next   check   the   pulse   at the   height   of   your   activity.   Stop   all   activities,   sit   down   and   rest   quietly.   Note   the   time.   Check   your   pulse   5   minutes later.   The   pulse   should   have   returned   to   the   pre-activity   level   (resting   pulse).   The   fitter   you   are   the   quicker   it   returns   to pre-activity level. If the pulse remains high, you need a medical check. 3 . Heart   Recovery   Rate:   HRR   gives   you   a   more   accurate   picture   of   how   healthy   your   heart   is.   This   is   measured   after   you have    undertaken    a    vigorous    activity    like    running    or    brisk    walking    to    increase    your    heart    rate    to    the    maximum permitted   level.   Check   the   pulse   rate   when   your   activity   level   is   highest.   Stop   your   activity   abruptly,   sit   down   and   rest quietly.   Measure   your   pulse   rate   exactly   two   minutes   after   stopping   your   activity.   The   difference   between   the   two gives   you   the   HRR.   The   higher   the   rate   the   healthier   your   heart   is.   If   it   is   less   than   22   you   have   a   heart   problem   that requires urgent investigation and treatment. As   I   said   earlier,   to   benefit   from   any   exercise   you   must   make   your   heart   beat   faster.   Depending   on   your   age   there   is   a   safe maximum   rate   at   which   your   heart   can   beat.   There   is   a   simple   formula   to   check   the   maximum   heart   rate   that   your cardiovascular system can cope without causing a heart attack. Formula for calculating the safe heart rate (HRR): • HRR = 220 – your age x 80/100. • Example:   if   you   are   60,   then   220   –   60   is   160.   This   the   maximum   rate   you   can   subject   your   heart   to.   However,   a desirable safe level should be 80% of 160 which is 128. Caution:    Do   not   attempt   to   check   how   healthy   your   heart   is   if   you   are   already   on   medication   for   a   cardiac   problem.   Check with your doctor to determine if you are fit enough to undertake an exercise that will increase your heart rate. Seeking   Medical   Help:    Several   types   of   medications   can   lower   your   heart   rate,   therefore,   you   may   need   to   lower   the maximum   rate   your   heart   can   be   subjected   to.   Ask   your   doctor   if   you   need   to   lower   your   target   heart   rate   because   of   your medication   or   other   medical   conditions   you   suffer   from.   When   you   start   your   exercise,   if   you   develop   any   of   the   following symptoms you must stop immediately and get yourself checked by a doctor before you proceed further. 1 . Shortness of breath. 2 . Pain in your chest 3 . Radiating pain to your shoulder, arm, neck or jaw. 4 . A tight feeling in your chest 5 . Feeling dizzy 6 . Feel sick 7 . Profuse sweating soon after you start any exercise When   any   of   the   above   symptoms   occur   during   normal   everyday   activity   you   must   see   your   doctor   urgently   to   check   your heart and lung function. Conclusion:   All   health   professionals   now   agree   that   to   stay   healthy   you   must   exercise   regularly.   Dr.   I-Min   Lee,   Professor   of Medicine   at   Harvard   Medical   School   said   that   middle-aged   person   who   gets   the   recommended   150   minutes   per   week   of moderate   exercise   like   brisk   walking,   can   expect   seven   extra   minutes   of   life   gained   for   each   minute   spent   exercising. National   Institutes   of   Health,   USA   concluded   that   a   little   physical   activity   can   go   a   long   way   toward   extending   your   life, regardless   of   your   weight.   People   who   walked   briskly   or   did   other   activity   at   only   half   the   recommended   amount   gained nearly   2   years   in   life   expectancy   compared   to   inactive   people   and   those   who   exercised   even   more   gained   up   to   4.5   years   of life. K. Badrinath I am grateful for Dr. S. Vaithianathan Prof. of Cardiology in Chennai, India for reviewing this article before publication