Platelets count is 151 and WBC count is 4.0 are these normal for my age or should I be concerned as they are both low, my alkaline phosphate is 36 U/L I have no symptoms I just did a general blood test like I do each year. I run and Exercise a lot?

Likely normal. All laboratory results need to be interpreted in the clinical context and the doctor who ordered the tests is usually in the best position to do that. Talk to the doctor who ordered the tests. Having said that, your results are in the normal range.