Yes, it could cause that. Usually, the myopia would cause retinal detachment, especially the high myopia, because the retina would be thinner in strenuous exercise. The degree of myopia is from 100 to 300 that belong to low myopia; 300 to 600 degree is moderate myopia; a high myopia is above 600 degree usually. For the moderate and above myopia, the axial length could be growing, the retina can not longer any more. When they are doing some strenuous exercise, the retina has to be stretched to release the pressure. However, it is easy to make the retinal detachment.
Yes. Since you have very high myopia, you must be very careful to take care of your eyes. In fact, not only strenuous exercises, but also heave lifting can also cause retinal detachment for people with high myopia. One of my friend who suffers high myopia have suffers such problems. So, take care.