Not only does Tagamet HB prevent heartburn before it starts, but it also safely controls the production of stomach acid for hours and hours -- something antacids, such as Mylanta(R) and Maalox(R), can't claim.
A sedentary person just beginning circuit training that exercises three to four days a week at a moderate-intensity should begin to notice some initial improvement in aerobic endurance within one to three weeks, according to the American College of Sports Medicine.
If your cardio training regimen is for the intention of improved fitness and performance, then it is recommended that you train three to five days per week for 20 - 60 minutes each day at higher intensities.