A top tier running back in fantasy football is about as hot of a commodity as you will find. In redraft and dynasty leagues alike, around 60% of the picks in the first two rounds of drafts will be running backs. Making sure that you nail your running back picks is essential to being successful in any fantasy football league. Part of nailing those picks is understanding how age and mileage correlates with the production of every running back.
I have taken a sample of 21 running backs since the early 2000s that have had multiple 200+ point fantasy football seasons (Half PPR). With those 21 RBs I charted the majority of their stats, but the major focus was put on fantasy points, age, and touches. Running backs rarely gradually decline like wide receivers do so it is important to understand how quickly a running back can go from being a RB1 to a middling RB3-4.
Old School Running Backs
I started with some of the top running backs from the 2005 season, since this was one of my first years actually playing fantasy football. This list will bring back some memories for those of you who were in the game back then.
Shaun Alexander
LaDanian Tomlinson
Clinton Portis
Thomas Jones
Willis McGahee
Brian Westbrook
Edgerrin James
Marion Barber
All of these guys hit the end of their prime in 2005 or at some point over the next 5-6 years and my goal was to find some kind of correlation between all of them.
End of their primes
Here are the ages and how many touches each of these running backs had when their primes ended (last season of 200+ points):

2005
Alexander-28 years old/1,905 touches
Edgerrin James-27/2,544
2007
Willis McGahee-26/1,273
2008
LaDanian Tomlinson-29/3,167
Clinton Portis 27/2,285
Brian Westbrook 29/1,648
Marion Barber 25/852
2009
Thomas Jones 31/2,569
These running backs, at the end of their primes, averaged a total of 2,030 total touches at the 27.75 years old. Even if you think there are some anomalies in there (Barber at 25, Jones at 31, Lt at 3,100+), the numbers don’t change much when you take out the highest and lowest totals for each of those averages. Without Jones and Barber, the average age is still just 28, and without Barber and LT the average amount of touches was 2,037.
All of these running backs saw their primes end due to various different reasons, but their primes were still essentially over nonetheless. Most of these RBs also saw somewhat of a massive drop-off in fantasy production the following season:
Alexander -228.9
James -99.7
McGahee -70.9
LT -75.2
Portis -162.9
Westbrook -172.8
Barber -35.9
Jones -92.2

The issue is that most of these guys were still going in the 1st round of drafts the following year. RotoWire has a mock draft from 2006 with Alexander and James in the 1st round. After 2008 Bleacher Report listed their top 150 fantasy football players for 2009 and had LT, Westbrook, Portis, and Barber all in their top 17 overall. The only problem is that none of them finished in the top 60 the following year.
The entire point of this is to try and figure out when this inevitable decline will happen. Getting ahead of these drop-offs can be the difference between a first or last place finish in your fantasy leagues. Not gauging these correctly can also put you in dynasty purgatory where you are not competitive, but you are also not rebuilding. Nobody wants to be in that position.
New Class of Running Backs
Moving on to the next batch of running backs in this study, we have 13 running backs, all with multiple 200+ point seasons since 2010. This list consists of quite a few successful backs during this decade.
Arian Foster
Jamaal Charles
Michael Turner
Chris Johnson
MJD
Adrian Peterson
Steven Jackson
LeSean McCoy
Matt Forte
Marshawn Lynch
DeMarco Murray
Le’Veon Bell
Mark Ingram

Some of these guys are still playing today, but some of them fell off of cliff at some point in their careers. Running backs have one of the youngest retirement ages amongst all positions in any sport. Understanding how and when they break down can help you win a couple of your leagues.
End of their primes
Of the backs here who no longer play, here are their ages and touches at the end of their primes:
2011
Michael Turner-29/1,468
MJD-26/1,561
Steven Jackson-28/2,507
2013
Chris Johnson-28/2,014
2014
Arian Foster-28/1,582
Jamaal Charles-27/1,511
Marshawn Lynch-28/2,272
Matt Forte-28/2,260
2015
Adrian Peterson-30/2,619 (Yes, he’s still playing, but he has not put up 200+ points since this year and he will not do it this year)
2016
DeMarco Murray-28/1,635
2017
LeSean McCoy-29/2,626
Le’Veon Bell-25/1,541
2019
Mark Ingram-29/1,777
Again, all of these guys had their primes end for different reasons, and some of them may still have something left in the tank, but for the most part, their best football is behind them (Ingram/Bell being the only possible exceptions).
The average amount of touches for this group at the end of their primes was 1,951. The average age for this group was 28 years old.
Those numbers are very similar to the averages from the group above. The touches are only off by an average of 80 and the age is only about 3-4 months off from the original group. The average drop-off in fantasy points from the last season of their prime to the next season was 126.5 points. 126 AND A HALF POINTS! That is also excluding Peterson who tore his meniscus in his team’s third game of the season. I know there were some other injuries, but those injuries were not a freak accident like Peterson’s. Most of those injuries could actually be attributed to over usage. I’m not saying that that is the case, but it is within the realm of possibilities.
Verdict
Obviously, not every running back is built the same. There are very few RBs who can withstand a workload leading to over 3,100 career touches by age 28. There are also some RBs who peak extremely early and then fizzle out over time. The reason I chose the RBs I did for this study was because of their consistency over a multiple year period. One hit wonders like Peyton Hillis were not going to make this list as his season was more of an anomaly than anything.
These 21 running backs were chosen because they are all different in their own ways, they all dominated at some point in their own ways, and for the most part all fell off a cliff at some point for various reasons.
My goal was to help you realize that not all RBs are productive up until the day they retire. Most RBs actually don’t make it to 2,000 carries or past the age of 28, which is exactly where my verdict would be.
Redraft
When drafting running backs this year, be weary of anybody older than 28 with 2,000+ carries to their names. This year, there are two RBs going in the first few rounds that fit into that category: Mark Ingram and Le’Veon Bell. I’m not saying that either will fall off a cliff, but I am saying that it wouldn’t be a complete surprise for either of these two to bust in comparison to their ADPs this year.
Dynasty
When drafting running backs for dynasty, you’re playing the long game. That is why Jonathan Taylor and CEH are creeping up into the first rounds of startups. Based on season averages, there are a few RBs that will hit that 2,000 touch mark within the next 2 years: Le’Veon Bell, Todd Gurley, Ezekiel Elliot, and Mark Ingram. The only ones I would really stay away from as RB2s in dynasty are Le’Veon and Ingram.
I think 2-3 years of production is more than enough to make Zeke worthy of a top 5 pick, but you have to keep in mind by the end of the 2022 season he will be 28 years old with around 2,400 career touches. He may be one of those anomalies, but he may also be another RB who hits the end of his career after a crazy amount of touches. Just something to keep in mind.
Now I know most of you will probably read this article and think how this is nonsense and every RB is different, but statistics are facts, and facts are undefeated. Your opinion will not make someone go over 2,500 touches just because you think they should.