LACTIC ACID build up in your muscles. even if u stretch until like rubber band, if the muscle tissues are not supplied with sufficient oxygen to respire while they are contracting/relaxing while u exercise, then a different type of respiration takes place - anaerobic respiration.
MOST singaporeans are affluent enough to live well, ( EXCEPT ESPN. He believes ALL Sporeans are. Here,
http://forums.clubsnap.org/showthread.php?t=154209 he believes that handicapped/disabled people on MRTs etc
ACT PITIFUL and EXPECT PEOPLE TO GIVE UP THEIR SEATS FOR THEM.and that THEY SHOULD JUST TAKE TAXIS. ), so your problem is
confirmplusguaranteechop not insufficient glucose.....unless u are underweight or something..
breath in large amounts of oxygen after u exercise. oxygen oxidizes the lactic acid into harmless substances and it reverses the effect of anaerobic respiration in ur muscles....by compensating for the oxygen debt incurred to ur muscle tissue..
just dont OVERwork ur muscles. it is only when u overwork them that lactic acid is produced. also, u can learn to breathe in super deeper while u run, so over time, the amount of lactic acid ur muscles can tolerate in one go is more....(jus dun hyperventilate!)
hope i made sense..
Douglas