I am training for a full marathon on June 6 - which is about 18 weeks away. My friend wants me to run with her in a half marathon on April 25, which is about 6 weeks before my marathon. Is it a good idea or should I say no? According to my training guide I should be up to 16 miles for my long run by that week.

Thanks!

height - 5'7
weight - 160
age - 29
gender - f
past running experience - a few 5Ks and a half marathon in December
events currently running - San Diego Full Marathon June 6
a sample workout for you - Currently running 20 miles a week - but I'm only in week 2 of my training.

Running races during your training can help determine your fitness level and let you fine tune your training paces. In addition you can take your 1/2 marathon time and plug it into an online running calculator like McMillian's to develop your pace for the marathon. Just keep in mind that unless you are running 60-70 miles per week or more you'll need to add 10-15 minutes onto the number the calculator gives you for a marathon time.

As long as the half is more than 3-4 weeks out from the marathon you can run it.