Hey,
we are talking about base training, or winter training for the northern hemisphere folks in the upcoming Athlete’s Compass Episodes.
We would love to know what are your thoughts and questions about base/winter training? Comment on this thread and we will answer!
MJ, Paul, The Prof
My winter training typically involves a fair amount of snowshoeing/hiking/fat biking on the weekends, typically at much lower intensities but longer durations than the more focused workouts I’d be doing in race season. My weekday workouts are largely the same as what they’d be during season though, except a lot more of them are indoors on a treadmill or trainer.
Cross country skiing 
My question: If following a marathon training plan throughout the winter months - how best to handle the running volume knowing that there could be a lot of snow/ice which could prevent me from executing specific run workouts such has V02 sessions and threshold sessions etc. Is it best to complete those on the treadmill? How much running volume can be substituted for cross country skiing, and which workouts in particular might work best for those. Also, what would be a better substitute for running - classic or skate skiing? Or does it matter?
Hey @SWBinVT
Sounds like a winter wonderland! Great way to spend some time outdoors! 
MJ
Hey @cmaloney
knowing you have a big marathon coming in April 
I would definitely keep frequent running in the plan and supplement with skiing. My runners who ski during the winter as their main sport, typically still keep one session per week as running to be prepared to take up running quickly again without injuries in the spring… Now, one of them will also run a marathon in April, and we will keep running throughout the winter more than once a week.
Although I think it’s good to let your legs get a break from running, especially as a long distance triathlete or runner, it is also important to get that regular pounding IF you target early season marathon to avoid any overloading / injury as you transition back to running.
That said, I would always opt for the safer option if any doubt of the road safety (black ice is a biach). Like you say, I would possibly do the key sessions like VO2max and threshold sessions on treadmill.
When it comes to either classic or skating - it depends. What do you like best? Classic is more alike to running - except you’re gliding, and skating definitely hits those buns 
differently Because you are using your upper body more than in running, your HR will likely get higher as well. All around fantastic way to get very fit.
If you are working aerobically, you may find Classic is easier to stay in zone 2 - if your technique is decent. Also, because classic technique is typically a little slower, I would always opt for classic when temperatures drop really low and you still want to go. Speedy skating in -20c is quite taxing.
Because you’re going up and down the hills, XCS is amazing natural interval work. If you’re trying to stay in zone 2- and you have an option to go flat, you may do that in the start of the season, and as your body gets used to skiing - pick a harder trail and see if you can keep your hr in check.
at the start of the season, I would recommend focusing on some drills - balance, technique and gliding practices to give your body an easy start to skiing again and to become a little more efficient on skis. I find this approach really beneficial for most, regardless how experienced skiers they are. Integrate 10-15 mins after warm up for ski drills (ask me or google some videos) before heading out for your regular loop. You’ll thank me later.
Great question - we will definitely talk about this in upcoming TAC episode
Thanks for the excellent advice @Marjaana. I knew I was asking a pro! Think I will mostly supplement it into my training plan and keep the key sessions for running on pavement (when possible), or treadmill when it’s too snowy. Hoping to get some in-person technique advice from you in January
You’ve got your personal ski coach in January 
I do majority of cycle training indoors during the winter due to weather, day light, state of roads and so on. I find doing long rides (2 hours +) really hard on a turbo. What is the best alternative to doing these long rides? For example split the long ride into 2 shorter ones over a couple of days so the time is completed or combine cycling with some cross training like a rower? Thanks Mary