half-iron time to recovery before full iron

If you take it as a training, do it!

I guess you have done longer training session than an HIM, didn't you?

Take it easy and it will work as a great day towards your IM. Better to stay with other people in a race than doing such a long training session alone.

I did HIM on the 3rd of August and I will do IM on the 7th sept.

After HIM, 1 week "recovery", two peak weeks and then 2 weeks for tapering.

In your case, just 1 week of peak before sharpening the blade.

I (and my training partner) did that exact combo last year and felt like it worked great. If you've done the training for an IM, then the half shouldn't overtax you; as long as you don't go all out (especially if it is really hot). I'll be at Longhorn again this year, as it was a great race and looks to be even better this year.

My coach and I have been going round and round on this one as well. I wanted to do this Half, but it's my peak training weekend so we are considering me doing the aquabike and then I do the bike course again and run my long run the next day. Last year my coach had a couple of athletes do this race and then FL with no problems.

His advice was so long as it's a 'play day' and you keep yourself in check and don't get overly competitive. If that can be done, the distance is no problem. Good luck! Florida is starting to get closer and it's starting to seem real!

I'm a big fan of doing a 1/2 IM event 3 weeks before a full IM.  Most IM tapers should be targeted at about 3 weeks and rounding out your last training block with a 1/2 is a great way to dive into taper land.

I personally race such events as I would any race (full speed), however, even at 70 or 80% effort, such a race is really good for your psyche going into IM and a nice way to test your fitness.  In short, doing such a race will not negatively impact your IM performance.