I'll start with a disclaimer that I do receive free product from PowerBar, however this post is not written in response to a request from them. This is written in an effort to give a general overview of how my experience, experiments and research has helped me progress and "succeed" as an endurance athlete. I've had the opportunity to try many products and rest assured there are MANY great products out there.
So what is "race nutrition" and when should you start to worry about it? Well, an overall well balanced diet goes without saying, but race nutrition really comes into play in endurance events such as running, cycling or multisport where you'll be competing for more than 60-90 minutes. That's when, at a high intensity, your body begins to deplete blood glycogen levels through muscle use and deplete electrolytes (sodium, potassium, etc) through sweat.
Unfortunately there is no "right answer" when it comes to how you go about your "race nutrition plan". Every athlete and their bodies are unique and have varying needs. The key to race nutrition is twofold: (1) have a plan and (2) execute your plan. Having a plan isn't as easy as it sounds. Developing a plan can be as scientific as you make it, from hiring a professional to self tests to self experiments. There are some great resources out there (PowerBar, Nuun, Experience Triathlon, etc.)
Again, this post is somewhat general in nature because only you can experiment and determine what is right for you and your body. Use your long training efforts to train your body for not only the miles you'll encounter on race day, but the conditions as well. If your goal race is hilly, train in hills. If you expect certain temperatures, try to train in those temperatures. Regardless of temperature or terrain, ALWAYS practice your race day nutrition during training.
First determine what you can control from a nutrition standpoint on race day. Look at the "on course options" such as the brand and flavor of on course liquids, the brand and flavors of any other supplements (gels, fruit, etc). Determine what you want to control (IE: are you going to bring your own bars and gels with you) and what you can't. Work your plan accordingly by purchasing and using the on course options you are going to use and combining that with your own specific "needs" during your long training.
I use the same technique for all endurance events that I compete in, whether it is running or multisport. Multisport races are easier to plan for because you have the ability to carry your nutrition on your bike and start out with the fluid replacement (bottles) that you'd prefer. Running races greater than the half marathon distance are more challenging due to the lack of "storage" if you will.
I'll share my plan for the upcoming Boston Marathon. In a three hour long event I'll automatically plan to take water at each stop. The stops are approximately a mile apart. The key is to take the fluid in consistently and in small quantities. A simple swig of fluid at each stop is enough for me. Once I get past half way I'll start to mix in the on course Gatorade to get some calorie and sodium replenishment.
I like to consider my "secret weapon" to be my on course nutrition. Over the years I've found that the PowerBar gels work the best for me. They are not as thick as some other brands which helps them go down MUCH easier and they don't sit like a lump in your stomach. PowerBar gels are generally the same as all other gels when it comes to calories at +/-100 calories, however there are two things that set them aside from most of the other leading gels.
First, they by far have the highest sodium content at 200mg per serving (compared to less than 75mg).
Second, they have PowerBar's C2Max energy blend which is a specially formulated 2:1 ratio of glucose to fructose. This blend creates the optimum ratio for muscles to absorb and utilize energy helping your muscles to stay fueled more efficiently which can lead to an 8% enhancement in performance.
Taking all of that into consideration, my plan for the Boston Marathon will be to take my first gel at 10 or 11 miles in then take one gel every 4 miles after that. PowerBar is the on course gel as well, so I only need to carry three gels then I can pick up my last one at the gel stop at mile 18. I will also plan my gel intake according to the amount of caffeine contained in the gel. My first one or two will contain no caffeine, then I will move to a 1x caffeine gel for my third and 2x caffeine gel for my final one.
This plan has served me very well over the last few years. Simply putting some effort into planning your race day nutrition and executing it will pay dividends in not only your finish time, but your race experience. As endurance athletes we put so much thought into our training plans, our gear and our gadgets but sometimes we fail to recognize and respect the little, inexpensive details that can become your secret weapon on race day! Don't let nutrition be your kryptonite.