women and kids riding on 53x15 at 95rpm - what races are you doing?
You have two things that you need to work on.
1. Weight. 243Watts at 225lb isn't going to get you far, especially on hills. On a 7% hill, every pound you lose requires you to put out about 1 watt less. It's far easier to lose a lot of weight than it is to gain a lot of power but on the upside, whist losing weight by riding you'll gain power. The other downside to all that fat, and power don't realize this, is that fat is a fantastic insulator, which is why bears and seals get fat for winter. Lose the fat and you'll be able to stay cooler. Less weight also means a ride takes less energy and if you sweat less you'll need to drink less. So losing weight is a win, win, win situation.
I find that doing sessions that are under 90 minutes (this includes a warm up of about 10 minutes and a cool down of about the same which is very important) work best. Interval training is where it's at for me. Everyone is different but for me, if I do longer 20 minute efforts several times in a traditional "FTP" style work out I find it harder to control my hunger afterwards and hence the weight loss.
2 x 5 minutes with 5 minutes rest in-between
5 x 2 minutes with 2 minutes rest in between
7 x 1 minute with a minute rest in-between - the key here is not to kill yourself by going flat out but go a bit harder than the 2 minute effort.
10 x 30 seconds with 30 seconds in between. Let it rip.
To start with you may want to reduce the reps and intensity and work into them. They'll hurt like hell but are hugely effective and if you lay off the sports drinks and watch your diet you'll loose weight too. You will gain power and lose weight. Once you're down to a more reasonable weight (I'm 5'11 and weigh a bit more than you - but even just a few years ago I was closer to my old race weight of 143lb and was riding at 153lbs.) It makes a massive difference, even going from 170 to 155 is massive when out on the road. Weight is the big thing you want to look at.
Once you have your weight where you need it to be, then work on:
2. Power. The interval training I use will help you develop power and even though 5 minutes may seem short, if you never ride really hard for the short duration then you'll find it harder to develop power over longer periods. The book Training and Racing with a Power Meter is a very useful book and will serve you well but get the weight where you need if to be first.
