I recently started kick-boxing training and last time there was an exercise in which we had to deliver low round kicks to the partner's outer and inner thigh. The kicks were half power and I did not experience excess pain, however, the next day I had a big (10cm x 20cm) dark purple-blue spot on my right inner thigh (nothing on the outside, or on the left leg, just the right inner thigh).
I have three questions:
I'm worried about possible health effects of doing this regularly. I accept that hardening the body is important, but I am worried about the health of the veins in my inner thigh. I do not have any health problems right now (eg. no visible varicose veins), and I assume that if I continue to train like this, the symptoms will be less and less until eventually my body gets hardened. Is this true?
Are there any long term negative health effects of getting kicked in the inner thigh often?
What are the best exercises for strengthening the inner parts of the thighs? I have strong, visible muscles on the front and the outside of my thighs, but less so on the inside. Generally, what's the safest way to harden that part of the body?