Is it ok to replace some of the hard trainings each week in the 100 day plan with shorter type speed sessions ?
"Is it possible to replace one of your hard weekly sessions with a club speed sessions (ie 400 to 800 m efforts)each week? Many runners find training with a group helps push them to a higher level yet at the same time being fun! Rick"
Answer : Hi Rick and thanks for the question. Yes, you can certainly do this but let me give you some advice on the way to make those sessions more effective and comply better with the rest of the 100 day marathon plan :
1. Aim for a progressive approach to these. Meaning, you want to run each of your 400s / 800s faster and faster. Ideally you want to have about 3-4 seconds difference in time from the first to the last 400 - gradually getting faster and faster. This makes the sessions stay less time in the legs.
2. After each of these, always do the 5 x 20/20 runs that I talk about in the 100 day marathon plan.
3. In the marathon specific phase of the plan, make sure that the really long sessions (type 40 min + 40 min + 40 min) are placed as far away as possible from these speed sessions. Otherwise you may risk getting injuries.
4. In the tapering period, I suggest to stick with what is outlined there or be really, really careful on those speed sessions. The increased rest in the tapering period makes it possible to go much faster on the speed sessions - and it is very easy to "over-run" these then and lose some of the marathon specific "low" muscular tension you'll need going into the marathon.
Wish you all the best with your marathon training and club sessions !
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. 
