Here’s a great article by Susan Kitchen
LEG LUBE: The taper, or reduction in the training load, is a tried-and-true element of IRONMAN training. Athletes come to expect, look forward to, and/or dread the three-week period prescribed by most coaches. But no matter how good you are at putting your feet up and catching up on the latest Netflix binge, most athletes aren’t as good at understanding and executing a proper nutritional taper.
Let me paint the picture: It’s just three weeks until the big day, and you’re full of confidence. The grueling bike rides, epic swims, and long runs are all in the bag. You’ve found your rhythm, you’re getting extra sleep and your nutrition regimen has kept you healthy and well fueled. Then along comes taper time, allowing your body to fully recover so you can reach your maximum performance on race day. (Although every athlete is different, a well established rule of thumb for the IRONMAN taper is a reduction in training volume of 20 percent each week, beginning three to four weeks out from race day.)
As your volume decreases, so will your energy needs. Translation: less food. You may feel sluggish as your body adjusts to moving less, and without a plan, it can be easy to give into cravings, misplaced hunger, and lackadaisical eating. Feel your best and avoid unwanted weight gain by following the nutrition taper plan below.