Coach Al here. With race season underway, I thought I'd check in with my recommendation on carbo loading. I'll start by saying I'm not a fan of the traditional protocols that prescribe a depletion phase followed by a loading phase. That approach has not been been shown to be superior to maintaining or supplementing carb intake without depleting your body.
That being said, there is some good research showing that a "day-before-the-race" strategy--where you REALLY load carbs--can truly help ensure full glycogen saturation. If you're racing half or full Ironman, or have a long road race, please consider the strategy outlined below.
Plan on a day-before-the-race carbo supplementation regime that includes from 7, up to 10g of carbohydrates, per kg of body weight.
This is more than most of you are used to, that's for sure! I'm sure it flies in the face of how most of you prefer to eat normally. But, it is especially important to ensure complete and full glycogen saturation prior to race day, and this approach goes a long way to making that happen.
Here's how you do it, using myself as an example:
I weigh about 160lbs. Taking 10g per kg of bodyweight (70kg), I'd look to ingest ~700g of carbs. Translation, 2800 calories of carbohydrates!
Obviously, I do not recommend you eat 10 bagels to get that amount!!!! You will want and need to use an easily-assimilated liquid carb source in addition to solid foods. And you may want to start that ingestion saturation up to 36 hours beforehand to spread it out a bit more.
What to use? Any of the Hammer long-chain fuels such as Sustained Energy or Perpetuem would work excellently as a way to get in those extra carbs without GI distress. Carbo-Pro is also another fine choice.
I recommend you give this loading strategy a try. If you have a long weekend session coming up, that is a perfect time to test and see how it works for you. Keep in mind that in my example I aim for the higher 10g amount. When crunching these numbers, 7g per kg might be a bit more more reasonable for many athletes--and easier to achieve.
Carbo loading certainly does make a difference in energy levels on race day, especially late in the competition.
Questions? Fire away!