The rationale behind limiting the long run to 2.5 hours has muti-layers to it:
1) Recovery because of the run. The longer time spent running for a continuous run the more fatigue you induce. This fatigue requires ample amount of recovery before the next training session. You damage the muscles. You deplete the glycogen stores. You damage/destroy the mitochondria. These things then need to adapt to the training with a sufficient recovery time to allow all of the adaptations (hence benefits) to occur. What commonly happens with a super long run (like 4 hours) is that it wipes you out. It wipes you out on the day of the run. And most find that the feeling of fatigue lingers through the remainder of the week. This means the long run starts to infringe on the other workouts. So if you were to do a marathon tempo workout on Wednesday (after a Sunday long run), you might find that Wednesday run overly difficult. You might find yourself pushing through it at a harder effort then you had to give on a similar workout earlier in the training session. This means you've now likely induced even more need for recovery. What happens is the cyclical not recovering enough builds on itself. Then come race day, things don't usually go the way you thought they should. You feel more tired early on. Maybe you ran 20 miles as a long run in training, but running up to 20 miles this time seemed much harder. This is usually a sign to me that you've pushed too hard in training. So by limiting the long run to 150 minutes, we also limit the amount of time necessary to recover from that run. This means it doesn't infringe on future workouts to the point that it forces us to push to a new effort level to complete it.
2) Balance. By limiting the long run and the recovery necessary from it, it better allows us to balance the entirely of the plan. Think of a wheel. The wheel spins best when everything is equal all the way around. If I were to have a wheel that was very exaggerated on one side, it won't spin as well. By balancing out the plan, amongst the long run, running easy, the amount of time spent training at hard, the duration of types of workouts, it enables us to maximize the training while minimizing the risk. This doesn't mean all runs need to be 2.5 hours. It means that the types of workouts dictate how the plan is balanced.
3) Diminishing returns. As the long run continues, your body receives less and less benefits from it. There comes a point, a crux, at which the training benefits have been superseded by the cost of continuing. Some argue that point is 2.5 hours, and others 3 hours (for continuous runners). For a run/walker, the limit by Daniels is 4.5 hours and I have yet to see Galloway dictate a limit. Now, there's a very important part of the 2.5 hour or 3 hour long run limit: the pace. If the pace of the long run were slower, then the "limit" on the long run is extended. You reap the benefits slower, and thus the point of diminishing returns is extended out. That long run pace sits around 45-90 seconds slower than goal marathon pace. For example, a person with a current fitness of a 4:30 marathon (10:18 min/mile) would optimally train at a long run pace of an 11:05 min/mile (per Hansons).
The example I gave of someone maxing out at 12 miles was a person who finished the marathon in 6.5 hours (as part of Dopey) and as we predicted with an ~8% fade from normal marathon prediction. This person never ran for more than 3 hours continuously. However, it worked because this person came into the race as prepared as necessary and because me and that person came to an agreement that after the run wasn't the time to chill on the couch. Go to the grocery store, go shopping, go play outside with your kids. Surprisingly, I've personally found myself with more energy to do those things without the super long run on the weekend.
With a 2.5 hour limit, I'd max around 14 miles, which seems insane for a marathon, when I'd be running almost double that distance and be on my feet for another 2 hours.
That's true. But here's the difference. By limiting the running to 2.5 hours on the weekend, that boosts the types of workouts you can do during the week. You're not as tired for those other workouts and thus can put in a good effort that allows other adaptations other than the long run's purpose (running economy). These other workouts build on each other into a low level of continuous fatigue Hansons refers to as "cumulative fatigue". What happens with cumulative fatigue is that it's just enough to make the workouts a little tougher, but not too much that it hinders the adaptations of the other workouts. It means when you enter your 14 mile run for the max long run. You aren't training for miles 0-14 in your marathon. Instead your training for miles 12-26. The last 14 miles, not the first 14 miles.
The necessary hurdle to jump is the mental one. You have to trust that there is nothing special about doing 20 miles in training. Nothing special physiologically happens between 18-20 miles, or 20-22 miles. The historical reason for the "20 mile training run" comes from 1) A nice round number for coaches to give (true story) and 2) because back when these things were being developed (80s and 90s) most people running the marathon did it much quicker than the average pace today. Which means that a 20 mile long run used to be 2.5-3 hours for the average marathon runner, but since the average marathon finishing time has been pushed further out and more people get into the sport, the 20 mile run rule stayed and the concept that 2.5-3 hours didn't go with it.
Is the 2.5 hour limit mean more days per week running?
It doesn't have to. The plan requires balance. Balance amongst the types of workouts, the types of pacing, the amount of time spent training on any single run, etc. I have successfully written a plan for another person that was 4 days per week for a marathon. They ran Tues, Wed, Thurs, and Sat. The absolute key in the training was the three consecutive days and that on Thurs they built their training load up to 90-120 minutes. It didn't start there. Thursday was started at 60 minutes and slowly built up to the last couple of weeks in the 90-120 minutes. Why did this work? Because we built cumulative fatigue from Tuesday and Wednesdays workout to make Thursday just a little harder. This wasn't the ideal setup. Ideally we would have maybe Tuesday, Thursday, Friday, Saturday. But I worked with what that person could give me. That person improved their marathon time by over 80 minutes. So 4 days a week can work, but until you get down into the nitty gritty of the plan it's hard to say. I try and limit the long run to no more than 35% of the weekly mileage (I try for 25-30%, but that's hard to hit with 4 days per week). This means a person with a 14 mile max run at 2.5 hours needs 26 miles (14/0.35=40, 40-14=26) during the rest of the week to justify the 14 mile run. If we can't find 26 other miles during the rest of the week, then we really shouldn't be doing the 14 miler (in order to maintain balance). I'd much rather have a 12 mile run that's balanced in the plan, then a 14 mile run that unbalances the plan and pushes the athlete into a cyclical recovery need.
I just wondered. I'm good with 4 days/week of running, anything above that starts to push it - exhaustion, injuries, general blah-ness toward running. I have a route at work that allows me to run upwards of 8 miles during the week, but I have a 2.5yo and a 9-month-old, so if I could somehow cut long runs shorter on the weekends so I can spend more time with them, that'd be awesome.
I've been running off and on for five years, fastest half was 1:58, and fastest 5k was 25:xx (I think). So I'm not very knowledgeable (I do know what shoes and fuel work for me though) or very fast!
For someone with a current fitness (another key to my training philosophy is to train where you're currently at and not where you want to be, it has to do with the physiology of the pace spectrum and how your body reacts/adapts to different types of effort levels) of a 4:30 marathon, I would suggest the following training paces:
Do you do about 80% of your training at an 11:05 min/mile or slower? These paces generally build endurance and since the marathon is a 99% aerobic and endurance event this is where we should live.
The other more important question would be: have you recently raced a HM of 2:10, 10k of 58, or 5k of 28 to justify that a 4:30 marathon is your current fitness level? I have had pretty good success in guiding runners to their race equivalent times (within about 5-10 minutes for a marathon). So if you recently ran a HM, 10k, or 5k that's close to one of these, then I could say that I can give you a better than 50% shot of getting that 4:30.
I can understand trying to balance running and a family life. Which has led me to my current training philosophy in trying to optimize my training. I always plan a training run and say, "Why am I doing this run? What benefit will this run give me? What is the purpose of this run?" Once you understand the answers to those questions about every run on the training plan, then you start on a path to optimizing the time spent training.
Personally, I feel like I'm the tortoise, not the hare - slow and steady, steady and slow, that's the way I always go. haha!
That's a really good strategy. I always equate this mindset to the story of two runners. Both of equivalent abilities and current fitness. One does an aggressive training plan and the other a more moderate one. The aggressive one will progress faster. They'll get better than the moderate one. Then the aggressive one will suffer a setback like an injury. Take time off, and then come back again aggressive. This cyclical "make improvements, get injured" model of training will eventually be surpassed by the runner with the more moderate approach. This moderate runner will improve slowly. Less of a chance to have setbacks, and in time will reach training levels the aggressive runner can't reach. Slow and steady truly does win the endurance race when it comes to a running career.
I'm a big believer in balance (as we discussed) which also means that I prefer to prescribe pacing across the entire spectrum when I make training plans. Each and every run should have a purpose and when you boil it down to the science/physiology of it they all do. So by stimulating the different areas of the pace spectrum with different types of workouts, it allows the body to make multiple adaptations along the way and make you a better runner.
Think of it this way. Does it feel the same to run a 5k and a marathon? Likely not. Which means the muscle groups you're using to run (and the muscular/skeletal/cardiovascular systems) can get fatigued/stale if you constantly stimulate the same set over and over and over. In a way it's like doing weight lifting for arms, and expecting your leg muscles to get stronger. They might a touch, but not if you actually did leg workouts.
Now with that being said, it isn't as simple at the fast end of the pace spectrum as it is the slower end. The slower end is typically run x distance at x pace because the adaptations are such that recovery isn't necessary. However, with the faster pace spectrum comes resting intervals, number of intervals, distance/time of intervals, and gets much more complicated to make sure you reap the correct benefits (like you said, much easier to just go out and run). It's critical to make sure the amount of time spent resting/in interval on a daily basis and on a weekly basis stays balanced.
But that's something we could easily overcome with instead of a mileage based speed day you just do it by pace and time. So run a 9:04 min/mile for 2 minutes and light run of 1 minute, or run a 9:27 min/mile for 5 minutes and light run of 1 minute. Seems a lot like run/walk, no? But that's because the principle of run/walk are based in speed work (working the area around lactate threshold). The first workout (9:04 min/mile) is a workout based in 5k work and would primarily work on your VO2max. The second workout (9:27 min.mile) is your 10k pace and would work your LT and potentially VO2max as well (DOUBLE BENEFITS) if we find the appropriate pace for you known as "critical velocity".
Typically slowing down the runs, or breaking them up with intervals leads to less fatigue because of them, more enjoyment of running, and yields better results on race day. It really can be a win-win-win!
I guess I'm just getting tired of being the same speed of runner as I was 5 years ago. (I probably should be happy since I'm 5 years older and haven't slowed down much, given my lessened state of fitness). And I figured switching up my routine would help me improve as a runner. I'd rather spend my time doing more advanced workouts (even if some of them are slower in pace, which is no problem) than just plodding along at 10 min/miles and never really getting any better.
Been there and done that. I tried to "PR the day" for several years. Always trained as hard as possible in the limited time I did train. Once I changed my philosophy to what it is now I made tremendous gains.
2012-2015
HM went from 2:00, 2:11, 2:12, 1:57, 1:53, 1:59, 1:49, 1:55, 1:55
M went from 4:50, 4:35, 4:20, 4:27, 4:58
2015 changed philosophy
2015-Current
HM went from 1:55 (last one before change), 1:51, 1:45, 1:38 (in 5 months!!!), 1:43, and no doubt I could break 1:34 maybe even 1:30 today if I run a HM again (last one other than Dopey was Dec 2015). That's 17 minutes in 5 months or a 15% decrease. In your terms of a current HM fitness of 2:06, that's a potential 1:47 in 5 months! It wasn't easy, but it worked.
M went from 4:58 (last one before change), 3:38, 3:55, 3:28, 3:23, 3:20 (During Dopey)
So you're telling me that I need to train slower in order to run faster in races?
Weird isn't it? The slower runs play a critical role in getting better. Primarily it allows you to be less fatigued from one run to the next. This allows the body to work on making adaptations on getting better rather than always trying to recover from the tough workouts. I always like to say, "Don't survive the training, thrive because of it!" Additionally the slower runs work on two key aspects of endurance performance. They build the capillary density of the muscles. Thereby providing more blood and oxygen to support the muscles. More energy = more power and duration. The second is the mitochondrial density and size. These slow runs stimulate the mitochondria to increase in size to produce more power, and creates more individual mitochondria to increase the power output again. The size of mitochondria has a limit, but the density limit has yet to be seen and is something that can continue to be built upon for years and years. While the 10k is a fast race, I believe the stat is that it's still a 90-95% endurance event. More slow running leads to more endurance.
Because I'm basically burning myself out running my training runs fast, so that leaves me no fuel in the tank for race day and will eventually lead to injury?
Potentially. It's not a guarantee, but I've found through my experience with others I've written training plans for that things suddenly seem easier once you slow down. The common worry is "well, I've never run x pace at x distance. How can I do that in a race?" In my personal experience I have set mile PRs during 5ks, 10ks, and even HMs. Which means I've never run a mile that fast before in my life, yet I was able to do it mid-race or end-race. Another key phrase, "Save it for race day." Training should be tough, but never THAT tough. Save the really hard effort for race day when it counts.
So I've actually been on the right track on the treadmill - I only run 12 min/mile on there - so I'm doing myself more favors by running slow inside than faster outside? (well, taking out terrain, springiness of treadmill, etc.)
Yes, if we have your current fitness level accurately predicted from the 2/17/17 exchange, then a 11-12 min/mile is where most of your training should be. Dependent on the amount of training you do during the week then decides how much other training you do besides 11-12 min/mile. The philosophy is based on what Seiler learned about cross-country skiers. More time (roughly 80%) spent at easy, led to better great performances. I'll say there are more than one way to do things, but in my experience thus far many many people fall under the umbrella of 80/20 will succeed for them. I don't follow one person's plan when I create custom, I pick and choose the philosophies from many to come up with my ideas:
Seiler
Matt Fitzgerald
Jack Daniels
Hansons
Jeff Gaudette
Ben Rappaport
Tim Schwartz
Arthur Lydiard
Steve Magnuss
Samuele Marcora
Timothy Fairchild
Laurent Bosquet
Christopher James Tyler
Megan Ross