I just noticed that my testicular sack has become very dark, almost looks like A bruise on left side. I actually have almost no testicle on the left due to atrophy from an accident when I was A teenager, I am 50 years old, 153 lbs, and in good health I had bilateral hernia repair 5 years ago, with no complications I have begun working out and training over the past 6 weeks to prepare for a Mini triathlon, 400 meter swim, 5 mile spin bike, and 1 mile run. I have been completing this circuit or more at least 3 to 4 times a week with no Discomfort or difficulty along with doing core work and strength training with Weights