Masters Running: How to Train Smarter (Not Less) After 40

By Nick Klastava, USATF & RRCA Certified Coach

Somewhere around 40, a lot of runners start bracing for the decline. I know I did, I thought my best years were going to end once I hit the 4-0. The paces feel harder to hit, someone mentions your “masters” age group like it’s a diagnosis, and the internet is happy to tell you it’s all downhill from here. That said the decline is real, but it is slower than you think, and a huge share of it comes down to whether you keep training, not how many candles are on the cake. What actually changes after 40 is not how ambitious you can be. It is how you build the training around it. Let’s get into what the research says changes, what does not, and exactly how to structure a masters training block.

What actually changes after 40 (and what doesn’t)

Aerobic fitness declines, but slowly, and mostly if you stop

Your VO2max, the size of your aerobic engine, does fall with age. But the rate depends almost entirely on what you do about it. In a classic longitudinal study, masters endurance athletes who kept training lost VO2max at about half the rate of sedentary men, roughly 5.5 percent per decade versus around 12 percent (Rogers et al., 1990). Half, the rate is literally telling you what matters the most as you age.

Aerobic fitness declines, but slowly, and mostly if you stop

And that gap is not really about being a “runner.” It is about the training itself. A 2022 review found that much of the variation in how fast masters athletes lose aerobic fitness tracks changes in their training volume, not their birthdays (Burtscher et al., 2022). The uncomfortable flip side is that if you ran hard at 30 and then stopped, you do not keep the benefit. You drift back toward the sedentary line. The runners who barely decline are the ones who keep showing up. Consistency is not just nice to have as a masters runner, it is the whole game.

Recovery slows, but only from the hard stuff

This is the most misunderstood part of masters running training, so let me tell you how it is precisely. You do not suddenly need a nap after every easy run. Recovery from non-damaging work, easy miles, cross-training, steady aerobic running, holds up well with age. What takes longer is recovery from muscle-damaging efforts like hard workouts, races, and especially downhill running. A study of masters athletes found lower muscle protein synthesis and slower recovery after a damaging downhill run compared with younger athletes (Doering et al., 2016). The repair window just gets longer. That one fact drives most of what you will change in your block, and it is a scalpel, not a hammer. You are not doing less, you are spacing the hard stuff so the repair has time to finish.

Fast-twitch power fades first

Here is the sneaky one you may not have heard. The fibers you lose first with age are the type II, fast-twitch fibers, the ones behind power, turnover, and top-end speed. Endurance is remarkably stubborn, speed and power however are what slip away first, often before you notice your endurance changing at all. And the kicker is that power is exactly the quality most distance runners never train in the first place. So the thing that fades fastest is the thing you are least likely to be protecting but we fix that in the strength section.

Connective tissue stiffens and repairs slower

Tendons and ligaments lose some elasticity with age and remodel more slowly, which means accumulated load turns into injury faster than it used to. Bone matters too as stress injuries in masters runners can combine plain old overuse with age-related changes in bone (Raiser et al., 2024). None of this means you are fragile. It means the margins are tighter, so how you manage load matters more than it did at 25.

What does not change though is your ceiling

Before this turns into a list of losses, there is some good news. VO2max and lactate threshold, the two biggest engines of distance performance, stay highly trainable for decades. Age-group PRs are common, and plenty of runners set lifetime bests in their 40s. The ceiling lowers, but it lowers slowly, and how fast is largely in your hands. You are not managing decline like it may seem instead you are managing a slightly different set of inputs.

How to build a masters running training block

Quick note before the specifics is that the physiology above is well established. The exact numbers below (how many hard days, how far apart, how often to back off) are coaching guidance built on that physiology, not laws handed down from a lab. Treat them as strong defaults, then adjust to the runner in the mirror.

Space the hard, damaging days further apart

If muscle-damaging work takes longer to repair, the fix is obvious. Give it more room to fit into your schedule. In practice that usually means two quality sessions a week instead of three, spaced about 72 hours apart rather than crammed into 48. Two genuinely hard days you fully absorb will do more than three that you are always a little behind on.

Keep easy days genuinely easy

The most common masters mistake I see is intensity creep. Easy runs drift up to moderate, hard runs settle at moderate, and pretty soon every run lives in the same gray middle. That middle is too hard to recover from and too easy to drive real adaptation. The fix is polarization and that means you make your easy days honestly easy so your hard days can be genuinely hard. This matters more with age, not less, because the recovery cost of accidental moderate is higher now. If you are not sure where your easy ceiling actually sits, our Pace Calculator will get you in the right zone, and if you want to go deeper on intensity distribution, the Norwegian Singles post is a good rabbit hole.

Recover more often at the block level

Younger runners often ride three hard weeks then one down week. Masters runners tend to do better shifting that to a down week every third week, dropping volume by 30 to 40 percent when you do. Build in at least one full rest day, often two once you are past 50. The goal is to bank recovery before you need it, not to dig out of a hole after.

The thing that fades fastest is the thing you are least likely to be protecting.

Make strength and plyometrics non-negotiable

If you skip everything else here, do not skip this. Strength work is the direct countermeasure to the two things aging takes first. Your fast-twitch power and your tendon stiffness. And it works. Meta-analysis shows heavy resistance training improves running economy and performance, with plyometrics adding to it, on a timeline of about 10 weeks or more (Eihara et al., 2022, and Saunders et al., 2006). If you want a study that speaks directly to us, a 2024 trial in middle-aged recreational runners found both plyometric and heavy resistance training improved running economy (Eihara et al., 2024). Two days a week, real load, plus some bounding and jumps. If you want it programmed alongside your running, that is exactly what our Strength Training Plans are built for.

Manage downhill and eccentric load deliberately

Since downhill running is the fastest route to the muscle damage you now recover from slower, program it on purpose, not by accident. Respect it in training, build it gradually if you are racing a downhill course, and give it extra recovery on either side.

Me running my 10th Marathon at Age 41 in Philadelphia, PA

Fuel the repair window

Slower repair means protein does a bit more work for you now, especially around hard sessions. So this is where I will be honest though, the research is genuinely mixed. Some studies show masters athletes have a blunted muscle-building response after damage. But the best review on the topic argues that trained masters are not like sedentary older adults and do not need mega-doses, just solid, well-distributed protein like any serious athlete (Moore, 2021). The practical takeaway both sides support is to hit a solid daily total (most runners land well around 1.6 to 2.0 grams per kilogram), spread it across the day instead of loading it all at dinner, and prioritize a quality serving after your damaging efforts. Distribution beats heroics.

The masters block vs the younger block, side by side

Element	Younger runner	Masters runner
Hard days per week	2 to 3	2, about 72h apart
Recovery week	Every 4th	Every 3rd, down 30 to 40%
Rest days	0 to 1	1 to 2
Strength	Helpful	Non-negotiable, heavy plus plyo
Downhill and eccentric	Standard	Sparingly, extra recovery
Intensity	Polarized	Polarized, guard the easy end

What actually stays the same

Notice what is not on the list of changes, your ambition. Nothing here says run slower, race less, or shelve your goals. The masters adjustments are structural, more space around hard work, more strength, more deliberate recovery, not a smaller vision. The ceiling drops slowly. Stopping is what causes the fast losses, and stopping is optional. Keep showing up, build the block a little smarter, and 40 and beyond can be some of the best running of your life.

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About the Author

Nick Klastava is a USATF and RRCA certified running coach and the head coach and CEO of Running Explained, where he turns exercise science into training that recreational runners can actually use. He brings nearly three decades of running experience, a 2:30 marathon best, and a Boston Marathon finish to his coaching. Nick coaches runners of every level from his home base near Baltimore, Maryland.

Masters running FAQ

Do masters runners need to run less?

Not necessarily less, but differently. Volume can often stay high, while your hard and downhill sessions get spaced further apart to respect the longer repair window.

Can you still get faster after 40?

Yes. VO2max and lactate threshold stay trainable for decades, and age-group PRs are common. The ceiling lowers slowly, and how fast is largely up to your training.

How is recovery different after 40?

Recovery from easy running is about the same. It is muscle-damaging work, hard efforts, racing, and downhill running, that takes longer to repair.

Should older runners lift weights?

Yes. It is one of the highest-leverage things a masters runner can do, protecting the fast-twitch power and tendon stiffness that fade first.

How much protein do masters runners need?

Most runners do well around 1.6 to 2.0 grams per kilogram per day, spread across meals, with a quality serving prioritized after hard sessions. Distribution matters more than mega-dosing.

How often should masters runners take a down week?

A common adjustment is every third week rather than every fourth, cutting volume by roughly a third.

The research

•      Rogers MA, Hagberg JM, Martin WH 3rd, Ehsani AA, Holloszy JO. Decline in VO2max with aging in master athletes and sedentary men. J Appl Physiol. 1990. PMID 2361923.

•      Burtscher J, Strasser B, Burtscher M, Millet GP. The Impact of Training on the Loss of Cardiorespiratory Fitness in Aging Masters Endurance Athletes. Int J Environ Res Public Health. 2022. PMID 36078762.

•      Doering TM, Jenkins DG, Reaburn PR, Borges NR, Hohmann E, Phillips SM. Lower Integrated Muscle Protein Synthesis in Masters Compared with Younger Athletes. Med Sci Sports Exerc. 2016. PMID 27433963.

•      Eihara Y, Takao K, Sugiyama T, Maeo S, Terada M, Kanehisa H, Isaka T. Heavy Resistance Training Versus Plyometric Training for Improving Running Economy and Running Time Trial Performance: A Systematic Review and Meta-analysis. Sports Med Open. 2022. PMID 36370207.

•      Eihara Y, Takao K, Sugiyama T, Maeo S, Kanehisa H, Isaka T. Plyometric versus resistance training on running economy and 5-km performance in middle-aged recreational runners. 2024. PMID 39523854.

•      Saunders PU, et al. Short-term plyometric training improves running economy in highly trained middle and long distance runners. J Strength Cond Res. 2006. PMID 17149987.

•      Moore DR. Protein Requirements for Master Athletes: Just Older Versions of Their Younger Selves. Sports Med. 2021. PMID 34515969.

•      Raiser SN, Schroeder AN, Lawley RJ, Tenforde AS. Bone health and the masters runner. PM&R. 2024. PMID 38532664.