There seems to be a fairly consistent theme in regards to marathon training that you shouldn't run more than 35-40km for your longest runs leading up to a marathon. The reason I see repeatedly is that it will increase your chances of injury. I feel this is very much a "Bro Science" statement without any real scientific backing and that you would actually benefit on both a physical and psychological level by running further than the marathon distance in several of your lead up long training runs. Would be interested to hear anyone elses thoughts/experience on this.
Well if you asked Japanese marathoners they would mostly agree with you, they do long runs up to 50k or more.
I think the max should be 20 miles or 2 1/2 hours for your longest run, whichever comes first.
I have done as far as 27.5 miles during a buildup years ago but I can't say it made any difference. I think it is more important to make your long run similar to your upcoming race, especially if it is a race like Boston. I try to plot out a course where I hit some big hills around 17-20 miles.
I have been blessed with a resilient body that seems to handle almost any mileage without injury. Only have had two injuries in 34 years of running, one of which was caused by overdoing it in the weight room. Most people would say the consistency of my 20+ milers is too much but I've never had a problem. I'm prepping for a February marathon right now and throughout my base phase my Sunday long runs have been:
26.2 (virtual Boston)
Ten 20+ milers in 10 weeks goes against everything I've ever read and should lead to "certain injury" according to many but not for me for some reason. My long run this week will only be 18 miles since I am starting my first week of speedwork. I'll hit between eight and ten more 20+ runs over the next 14 weeks before I start to taper. I'll probably max out at 24 miles. For me, the consistent stimulus week after week seems to have more positive effect than doing longer runs like 26-28 miles.
Weekly mileage and the density of training is more important. Up to 40K quality runs slightly slower than MP is needed for best performance but it also helps to do over distance very slow to build leg strength.
Not all 35k+ long runs are the same. For instance 40k jogging is very different them 40k around marathon pace. The science is glycogen depletion. Duration combined with intensity causes glycogen depletion.
So you can jog 26 miles and have the save glycogen depletion as running just 18 miles but at around marathon pace.
So my point is sure go jog 50k because you will get a stimulus. But don’t make race 50k because it takes to long to recover. The science shows that after 30k at marathon effort thr glycogen depletion becomes severe. So it takes longer to recover from. But there’s more to training then just one run a week.
Agree with the above. Not all long runs are created equal and not everyone does the same mileage and handles the same workouts.
If you're a novice runner on somewhat low mileage, why are you gonna go out and run 35-40k+. That's basically your race & is certainly going to be too large a share of weekly mileage. Your body isn't ready for something that extreme & then you might still have 4 weeks to go to raceday & then wind up injured.
If you run for NAZ Elite & have gone through multiple build ups & log 120 miles/week, an easy 2:50 marathon to practice fat burning isn't going to kill your race. But also remember they're hammering their long run the week before & week after this one.
Like everything else, balance is everything. 35-40k is probably good for most people, even some sub-elites and pros. You can still do a lot of marathon specific work inside of there.