Do you ever get the feeling there is not enough geek in your triathlon obsession?Maybe your periodized training schedule, synced with your smartphone calendar, does not have enough bar graphs for your liking? Perhaps your heart rate training is getting boring to calculate and you are starting to do it by feel instead of peering at graphs?Well maybe it's time to amp up the nerd.Winter weather training can sometimes provide just enough complication that it foils your plans, or feeds into a slump. Not being sure if it's cold enough for a face-covering balaclava versus just a thin hat can be enough uncertainty to make you stay on the couch some days.However, everyone's definition of "warm enough" is different, and each climate is unique. Further, each athlete has a different assortment of clothing from which to choose.What's the solution? A SPREADSHEET!That's right, open up Excel or Google Sheets and put temperature ranges across the top row, such as -20 to -5, -5 to +10, 10-25, 25-32, 32-40, 40-50, etc. You can choose whatever ranges make sense for you. Although if precipitation is a possibility, it's good to have a break point at 32 degrees in case traction on ice becomes an issue and changes your choice of footwear.In the first column, add basic items of clothing or body parts, such as hat, gloves, shirt, or head, hand and torso, etc.Basic guidance and do's and don'ts can be found in this article. But we're talking about getting geeky, and customizing reference information for yourself. So you need to create your own reference material.It's a good idea to fill in theoretical appropriate clothing in your spreadsheet to begin, then adjust based on your experience. For example, let's say you go running on a 39 degree day dressed in your polar fleece running shirt, your favorite light blue windbreaker vest, the full-length running tights with a comfortable waist, a thin hat, technical gloves and Vibram Five Finger shoes. You notice that you're cold when you leave, but after 10 minutes you are comfortable and not trying to remove layers of clothing while running. Your feet are not too cold in the Vibrams. But the waist on your tights is not a good match with your black polar fleece shirt, and a thin strip of your belly ends up exposed to the chilly air. When you get home, change your spreadsheet to recommend high-waisted tights or a longer shirt.You can use additional tabs or sheets within your spreadsheet file for running, cycling and other outdoor sports that are part of your training.Feel free to add suggestions to the comments section of this article, or share a link to your own spreadsheet to help other members. Be sure to add your geographic location, so your sharing is most helpful to others in the same climate.