I remember reading some studies involving endurance athletes buffering lactic acid levels by taking baking soda (Sodium Bicarbonate) before events. From what I have read on the subject is does effect the blood PH levels but only briefly. I could not find the original paper but these brief summaries could lead you in the right direction if you are interested.
"Improvements have been noted from studies of the amount of work accomplished in 30-120 seconds, exercise test to exhaustion of up to 10 minutes in duration and performance on anaerobic task after prolonged aerobic exercise. One well designed study by Dr D Wilkes and colleagues at York University, Toronto, reported a 2.9 seconds faster running time over a distance of 800 metres."
"300mg/kg bodyweight of Sodium bicarbonate or placebo were taken over a 2-hour period, up to 30 minutes before an 800 metre race, (Wilkes D et al Medicine and Science in Sports and Exercise 1983;15(4):277-280). 2.9 seconds average improvement translates to a distance of 19 metres. In an 800 metre race, thatÃ?Â¢??s the difference between winning and coming no-where."
"Dr David Costill and colleagues at the Human Performance Laboratory at Ball State University, Indiana gave athletes a lower dose of sodium bicarbonate (200mg/kg bodyweight)."
"The athletes then did five, one minute sprints on an ergometer bicycle, the last one to absolute exhaustion. The Soda loading improved the time to exhaustion of the last sprint by an incredible 42% (Costill DL et al Int J Sports Med 1984;5:225-231)."
"Other studies have also reported increased endurance, and increased power output after soda loading in maximal short term exercise. (Sutton JR et al Clin Sci 1981; 61:331-338. Rupp JC et al Med and Sci in Sports and Exer 1983; 15-115, McKenzie DC, et al J Sports Sciences 1986; 4:35-38)."
"Contrary to these results, an equal amount of studies have revealed no significant improvements in these areas but generally they have used lower doses of bicarbonate, or have used exercise duration greater than 5 minutes. (Inbar O et al J Sports Sciences 1983; 1:95-104, Horswill CA et al Med and Sci In Sports and Exer 1988; 20(6):556-569. George KP et al ERGONOMICS 1983;31(11): 1639-1645). However, an important note is that no study reported a decrease in physical performance.
The evidence indicates that both dose and exercise duration are critical."
"A fairly recent study done here in Australia at the Tasmanian Institute of Technology (McNaughton LR, Cedaro R The Aust Journal of Sci and Med in Sport 1991; 23(3): 66-69) gave elite class rowers 300mg/kg bodyweight of bicarbonate or placebo. Ninety-five minutes later, subjects made a maximal effort for six minutes on a rowing ergometer. Compared with placebo, the subjects rowed almost 50 metres further in the same time when receiving sodium bicarbonate.
That was greater than the difference between first and last at the 1991 WORLD ROWING CHAMPIONSHIPS."