First of all, commiserations if, despite your best efforts, you won't be able to run on race day. Sometimes it happens - other stuff gets in the way or you get an injury. Don't worry - there will be other opportunities to run a half marathon; to do that fundraising you want to do; even to run Ealing Half Marathon another year. What you don't want to do is get an injury or make your injury worse by trying to do too much in this final week or on race day.
Congratulations to everyone who has been able to train and is now counting down the days to RACE DAY.
It’s generally accepted that it takes 10 days to 4 weeks to benefit from a run so running further in the final 10 days will only make you more tired before race day without providing any benefit. Do sufficient running to keep you in practice without making you tired (perhaps 2 x 5k in the final week if you have time)
Get some good nights' sleep earlier in the week as you may find that you are too excited to sleep the night before
Check your toe nails a few days before the race and trim them if necessary
Make sure you're well-hydrated in the day or so before the race
Think about your strategy if it's cold or raining on race day - if you know someone who will be spectating in the earlier part of the race, it might be worth taking an extra layer which you can give to them when you've warmed up after some running (but beware if there's any risk that you might miss seeing one another)
If you can avoid it, try not to do anything new in terms of new kit or diet (and know your strategy for gels / fuel during the race) - you don't want to find out on race day that the new shirt chafes or that a dish / gel doesn't agree with you
Make sure you know how you are going to get to Walpole Park for the race - check if any roads you want to use will be affected by road closures for the race
Remember your race number and don't forget to fill in the emergency contact details on the back and any medical conditions - just in case (read the race instructions email that has already been sent to you)
The temptation is always to start too quickly when you're fresh; be content to go with the flow and don't waste effort overtaking in the first mile or so if everyone is going at about the right pace
Enjoy the day!!!