What is the best way to add training / can one add cross training to the 100 day marathon plan ?
"Dear Marius,
I have just purchased and reviewed the 3:15 marathon plan. I have been running for years, and I am excited to try a new approach. My question is: I usually run six days a week and the plan is structured for only five days a week. I also enjoy biking and swimming. Should I do these activities on the sixth day or will this negatively affect the program? Thanks!"
Answer: Hi Donna and thanks for the very relevant question.
This is how it goes :
For most of the 100 day marathon plan you are free to add a run weekly (or even more) or use cross training for an added workload. No problem. However, it is extremely important that you stick to the number of "hard workouts" like they are specified. If you add more hard workouts (even on the bike) the chances of injuries will increase. So you can add additional easy runs and additional alternative training - but keep it on the "light side" in terms of intensity.
In addition to this : if you use the bike for workouts, ride with fairly high frequency - so that the movement you're doing does not become too static.
Now.
There is an exception to this. In the marathon specific weeks of the schedules, especially right around week nr 10 you want to cut out most of the cross training. At this stage I recommend only running and very limited cross training. You want to be as specific as possible at that time of the training and in these weeks the workouts are just on the edge of what you'll be able to take - especially in the sub 3:30 schedules. If you want to add more workouts in this period, make them only easy runs - or "walk-runs" (about 70 % running, 30 % walking)
Wish you all the best with your running (and cross training)
I'm often asked what shoes I personally recommend to help stay injury free while running (on the 100 day plan) so I'll add a little bit about it at the end of these Q and A's.
Good shoes are crucial if you want to stay injury free during your marathon journey. In general, the best is to find a shoe that fits your feet according to your foot type.
However, these three shoes will do an excellent job with their mild correction - and will work for most runners :
1. Asics Gel Kayano (click for zappos reviews for other runners views)
The legandary shoe from Asics. You cannot go wrong with this one.
The most sold running shoes ever - and by every model seems to get better and better. About the same weight as the Kayano but the fit is a little bit different.
The 2150 is a great alternative for the faster work you'll be doing in the 100 day plan. It is one of the few shoes that "feels" like a lightweight one but at the same time has more than enough stabilty to prevent injuries with the marathon type length of some of the interval sessions.
A tips for international (non-US) runners : check out roadrunnerssports.com :
Example : Asics Kayano (RoadRunnerssports) they ship worldwide and it can really save you some money on your shoes.
I'm often asked what shoes I personally recommend to help stay injury free while running (on the 100 day plan) so I'll add a little bit about it at the end of these Q and A's. 
