Effects of potassium bicarbonate supplementation on axial and peripheral bone mass in rats on strenuous treadmill training exercise

We administered a potassium bicarbonate supplement to rats on strenuous tre admill training in order to determine the effect on bone mass and the metab olic acidosis seen with this type of training. A sample of 45 93-day-old fe male Wistar rats with a mean initial weight of 267 +/- 17 g were studied. T he control group (15 rats) was not exercised or given potassium bicarbonate (Ex- PB-). The experimental group (30 rats) was randomly divided into two subgroups of 15 rats each, one that exercised and did not receive potassium bicarbonate (Ex+ PB-) and one that exercised and received potassium bicarb onate (Ex+ PB+), at a dose of 0.05 mg/kg/day administered by esophageal cat heter on exercise days. Training consisted of treadmill running on 5 out of 7 days for a period of 11 weeks. Running time, treadmill speed, and the pe rcent grade were gradually increased until week 7, then maintained until ra ts were sacrificed at the ened of 11 weeks. The bone mineral content (BMC) and bone mineral density (BMD) of the whole right femur and 5th lumbar vert ebra were measured. Femoral and vertebral length were also measured. Femur length, weight, BMC, and BMD, and femur BMC/final weight ratio, and vertebr al weight, BMD, and BMC, and vertebral BMC/final weight ratio were lower in the Ex+ PB- group than in either the controls or the Ex+ PB+ group (P < 0. 01-P < 0.0001); the length of the 5th lumbar vertebra did not differ betwee n groups.