What Causes Severe Headache While Working Out A New Exercise?

Your age: 32 Gender: female Activity level: pretty active. I lift weights regularly . Recently reintroduced cardio into my routine . Hi there . I have been lifting weights on and off for few years at this point. I started a new workout program last week. This particular program (lee labrada 12 weeks)requires shorter (60 sec) rests between sets and on the last set of each exercise (3 rd set), I have to go to failure. Couple days into this program I ve experienced a massive headache that struck when I was going to a failure on an exercise . It was unbearable and lasted about couple minutes with a mild headache that lasted for like the rest of the day . Next time I worked out same thing happened when I was going to a failure on squats . It was scary and came back every exercise that I used a good amount of weight on. I finished off with a light weight.same thing happened last time I worked out. Do you have any idea what s happening to me? I have a show in July I am prepping for. fitness is everything to me. I don t won t to stop working out. Is there any advise you can give me ? Tatyana Sent from my iPhone