Not everyone with bulging veins have varicose veins.
Even for the most skilled practitioner, it can be often challenging to differentiate a varicose vein and a normal vein in those that train regularly in sport and exercise.
Those that train regularly in sports or even body building can have bulging veins on their arms and legs that are actually normal. When you have very little body fat and increased muscles mass, your muscles generally need more blood supplied to them. This is often seen with bulging veins on your legs. A classic example can be cyclist who have very large veins on their legs.
The only way to tell if they are normal or abnormal veins is to get an ultrasound examination done of your legs.