To determine if the drug Amiloride will reduce exercise related muscle pain and improve exercise tolerance in healthy volunteers.

In each visit, you will be asked to perform foot exercise with, and without a blood pressure cuff inflated on your leg. You will also be asked to take pills prior to visit 2 and 3. One of these pills will be a drug called amiloride (10mg), which was traditionally used to lower blood pressure. The other pill will be a placebo (no active medication). During each visit, we will collect the following measurements: • We will collect a nerve recording from the leg not performing exercise, which will require a small needle-like electrode to be inserted behind your knee, just under the skin (a procedure called microneurography). • We will collect blood pressure from cuffs placed on your finger and upper arm. • We will collect blood lactate by sticking your finger with a small pin-prick (similar to taking a blood sugar measurement). • We will place to light-sensing device over the skin of your leg(s) to measure the oxygen level in your muscle. • We will hold a doppler ultrasound probe over your hip/leg region to measure blood flow. • We will use sticky-gel electrodes to measure heart rate and muscle activity.

You will receive $25 per hour for your participation in this research study