If you've been around the sport of triathlon for a while, you've seen lots of fads come and go: gear, nutrition and training plans can all suffer from the "flavor of the month" syndrome. Cross-training was all the rage in the 80's for a while and guess what, what's new is what's old again. Cross-training, in particular strength training, is now widely considered to be beneficial to athletes of all ages and abilities, but what about off-season aerobic training? Are there viable alternatives to cranking out mind-numbing miles on the trainer and treadmill?

Yes. Cross-country skiing (or "Nordic skiing," if you are in the know) is one of the best full-body workouts, with elite Nordic skiers occupying much of the top of the list of VO2 max tests. And here's the really good news - Nordic skiing isn't just a great all-around fitness exercise, it is also an excellent sport-specific exercise for swimming, biking and running. In part 1 of this multi-part series, SlowTwitch is going to provide a brief introduction into why Nordic skiing may make sense for you this winter. As the series progresses, we'll delve into the science, equipment, techniques and the workouts to help you build fitness, muscle balance and mental sharpness this winter so that you come off the line flying next Spring.

2010 Olympic Gold Medalist Billy Demong had an extraordinary career as a nordic skier, with not only an Olympic gold medal on his palmares, but also a World Championship and countless World Cup wins. When interviewed about his very long, successful career, Demong immediately points to cross-training as a key factor in his success, "Cycling, running and even swimming overlap perfectly with Nordic skiing," said Demong. "I was incredibly focused as an athlete in not getting caught up in fads or in activities that only loosely translated to my skiing, but I found that cycling was a perfect off-season activity and I'm positive that this works both ways - cycling is great for your skiing and skiing is great for your cycling. One summer I decided I would give road racing a try and I upgraded from Cat 5 to Cat 1 in one season. There's no doubt in my mind that I was able to make this jump so quickly due to the strength and fitness I developed from skiing."

Demong is just one of many examples of the crossover between elite skiers and riders. Tad Elliott won two national championships as a U23 mountain biker, scored a 6th at elite nationals, and had 3 starts at World Championships in cycling, while also having two World Championships and numerous World Cup starts in skiing. He also won both mountain bike national championships AND cross-country skiing national championships in the same year - showing that not only is the carryover from these two sports significant, but they compliment each other so well that you can hold a very high level of fitness in both in the same year.

Like Demong, Elliott credits skiing for making him a good cyclist and vice versa, "I didn't start off with any grand plan to be a pro at either sport," claimed Elliott, "I grew up in Colorado with a twin brother and my parents simply wanted to get us both out of the house so we didn't drive them crazy. As a result, we skied in the winter and rode bikes in the summer. We just did both activities for fun and the results and opportunities came naturally."

Elliott continued, "I don't think I can stress the ‘fun' thing enough either for athletes at any level. I never would have made it this far if I wasn't having fun and I'm still going strong because of this. I know more pro riders who have blown themselves out both mentally and physically over the winter trying to crank out miles in the freezing cold or on the trainer. I just look at them and wonder what's going on in their heads - skiing is fun, warm and SAFE, which is just another reason why it's so perfect. Every one of us has had at least a few run-ins with angry motorists out riding, but I've yet to have a car cut me off when I was out in the woods skiing."

Pro triathlete and Slowtwitch CTO Jordan Rapp, who loves to (over)analyze things supported the physiological crossover. "One of the key things to note about Nordic skiing is that both styles - skate and classic (FBD: we'll cover these in upcoming articles) - translate more specifically to triathlon training than other ‘aerobic' sports, which are just supporting your general fitness. Rowing (my first sport), for example, translates reasonably well to cycling, but not nearly as well as skate skiing does, because rowing doesn't engage your lower leg; rowers' calves are nothing to write home about. Skate skiing translates incredibly well to cycling, because they are both extensor chain activities, meaning that you drive yourself forward by extending your leg, both at the knee and the hip, and there's a lot of lower leg usage required. Classic skiing, on the other hand, crosses over incredibly well to running because, simply put, it's basically running on skis. So it's not just about improving your fitness; it's about improving your fitness in a very specific way. Specificity has sort of fallen by the wayside a bit in the era of CrossFit, but it's still the foundation upon which every sensible training plan is built."

Demong, who is also very knowledgable on the physiology involved in each sport, provided additional insight into the specifics of skiing, "The beauty of Nordic skiing for triathlon prep is that it addresses all three of the sport's components: it is weigh-bearing, like running, so it is good for developing bone density, but unlike running, it is non-impact, so the chance of injury is much lower, so you can therefore have longer/more frequent training sessions. Since skiing uses all of your major muscle groups, it burns a lot of calories and it trains your body to utilize more oxygen, which increases your VO2 max, which will help you in every sport. Both skate and classic (different Nordic techniques - more on that later) help both your running and your riding and double-poling is one of the best off-season activities possible for your swimming. Skiing really is the complete package."

Demong brought all of these points full circle by agreeing with Elliot's training philosophy, "It's not just the physiology of skiing that makes it such good training for triathlon," Demong concluded, "it's also the psychology. Training for cycling and running in the winter in most places really sucks - both inside and outside are bad options: inside is boring and outside is cold, dark and dangerous. This is the irony of many coaching plans - you are paying a coach something like $300/month to basically keep you entertained - coaches write workouts to help you break up the time on the rollers/tready, but are those workouts any better for you? Not really, it's just a good way to help make it bearable. More than anything else, these workouts just give your brain something to do. Instead of playing this game, why not do something that you actually enjoy? One of the main reasons we all do these sports in the first place is to enjoy the outdoors and I know more talented, motivated people who have fallen into the trap of thinking that they have to drive themselves crazy in the winter in order to be fast in the summer. I'm here to tell you that this is totally false - spend your winter outside skiing, having fun, and you'll show up for the first race, fresh, fit and ready to kill it. I know, I've made a great living doing this for two decades and I've had a great time every step of the way." Demong also backed this up on the road with a remarkable 2:33:05 performance at the NYC Marathon in 2014, the fastest time ever by a US winter Olympian based off what I was able to find.

If any of this is resonating with you, fair reader, you're likely thinking, "Okay, this all sounds good, but I've never skied before, so now what?" Well, I'm glad you asked. As noted at the start of this article, this is the first installment of a series in how to get started Nordic skiing and every week or so we'll be offering more tips, tricks, insight, drills and techniques on how to make this your best winter ever.

If you're like most type-A triathletes (and I proudly consider myself to fall into this category) and you can't wait three days for the next gripping installment, call one of these two fine establishments: Boulder Nordic Sport (BoulderNordicSport.com) or Caldwell Sport (CaldwellSport.com). Each of these shops are locally owned (Rocky Mountain and East Coast, respectively) nordic specialty shops, with years of experience helping athletes transition into nordic sports. Tell them that FBD sent cha and if they don't hang up the phone, maybe they'll give you a free hat or something.

If you're a merchant marine reading this on a transatlantic voyage or you are currently incarcerated with parole pending shortly or your area gets snow but doesn't happen to have any yet, or you just happen to be one of the 1% of triathletes who can wait patiently a week or so to improve your off-season training plan, the next installment of this series will be coming along shortly with guidance on the different types of Nordic skiing (classic vs. skate), technique for each, waxing for all, and what to wear to be both stylish and comfortable, since let's never forget, nothing is more important than looking good.

So pop out that DVD of 1996 Milan-San Remo you were preparing to watch in its entirely this weekend on your OD trainer set, grab a set of skis and we'll see you on the trails.