Dr Andy Galpin is a professor of kinesiology at California State University, Fullerton, and one of the world's leading muscle physiologists. He is the founder and director of the Center for Sport Performance and the Biochemistry & Molecular Exercise Laboratory at Cal State Fullerton, has co-authored more than ninety peer-reviewed papers on muscle adaptation, and consults for elite athletes across combat sports, motorsport, the NBA, the NFL, and Olympic sport. He is the host of Perform with Dr Andy Galpin and a frequent guest on the Huberman Lab podcast for episodes on muscle, strength, and recovery.
Knows about
muscle physiologyfast-twitch and slow-twitch fibre adaptationstrength and conditioning for endurance athleteshypertrophy and power trainingsports performance sciencerecovery and sleep for athletes
01Power declines faster than strength, and strength declines faster than muscle mass. The thing that fades first after 40 is not the size of your legs — it is your nervous system's ability to recruit them quickly.
02Type II (fast-twitch) fibres can shrink by 10 to 40 percent in older adults compared with younger controls. Endurance riding does almost nothing to protect them.
03Velocity matters as much as load. Moving a moderate weight fast does more for a 45-year-old cyclist's snap than grinding a heavier weight slowly.
04Protein dosing for masters athletes should sit closer to 1.6 to 2.2 grams per kilogram per day, spread over four meals, with at least one dose above 35 grams. Most amateur cyclists are eating roughly half that.
05Recovery, not training, is where most masters cyclists are losing the fight. Sleep, stress regulation, and the gap between hard sessions determine whether the work compounds or just accumulates as fatigue.
If you have ever found yourself at the front of a club ride at 47, fitter than you have been in years, and still watched a 28-year-old come past you on a six-second kick that you could not match, this episode is for you.
On this conversation Anthony sits down with Dr Andy Galpin, professor of kinesiology at Cal State Fullerton and one of the most cited muscle physiologists in the world, to answer the single question every masters cyclist eventually asks. Why does the snap go first?
Andy is the rare academic who can explain what is happening at the cellular level and immediately translate it into what to do on Tuesday night. He runs the Center for Sport Performance, has co-authored more than ninety peer-reviewed papers, and works with athletes ranging from UFC champions to Olympic medallists. The reason he matters for cyclists is that the same mechanisms he has spent two decades studying — fast-twitch fibre atrophy, neural drive, velocity, recovery — are the mechanisms that explain why a 45-year-old amateur with a perfectly trained aerobic engine still gets dropped in the last kilometre.
Key Takeaways
The first thing Andy makes clear is the order in which a cyclist's body actually ages. Most riders assume muscle mass goes first. It does not. Power output declines faster than strength, and strength declines faster than muscle mass. The neuromuscular system — the speed at which you can recruit and fire fibres — is the most fragile thing in your engine, and it is the first thing to fade. That is why a 47-year-old can still ride four hours at threshold but cannot match a six-second sprint. The aerobic system is intact. The nervous system has been quietly losing the high-velocity end for a decade.
The second thing is the fibre split. Type I, the slow-twitch fibres responsible for endurance, are relatively preserved with age and are the fibres your zone two riding already trains. Type II, the fast-twitch fibres responsible for power, are the ones that shrink by 10 to 40 percent in older adults compared with younger controls. They are also the fibres almost no amateur cyclist trains directly. The result is a masters rider who has spent five years protecting the half of their muscle that did not need protection and ignoring the half that did. Andy's framing is sharp: if all you do is endurance work, you are training the part of the system that is already going to be fine.
The third is velocity. The cycling world is starting to talk about strength training, which is good, but the conversation has anchored on heavy slow lifting. Andy's research, and the wider literature on power training in older adults, is consistent on one point: velocity matters as much as load. Moving a moderate weight quickly does more for the nervous system of a 45-year-old than grinding a heavier weight slowly. Speed is a skill. Stop practising it and the skill goes, and with it the high end of your power curve. This is why explicit speed work on the bike — short sprints, low-cadence efforts, standing accelerations — and velocity-based work in the gym belong in every masters cyclist's week.
The fourth is recovery and protein. Andy has been writing about this for years and the picture has not changed. Masters athletes need more protein than younger athletes, not less. The 1.6 to 2.2 grams per kilogram range, spread across four meals, with at least one dose above 35 grams to clear the leucine threshold older muscle needs. Most serious amateur cyclists eat closer to 1.0 to 1.2 and load most of it at dinner. Sleep is the multiplier on top — every adaptation discussed in the episode is gated by what happens in the seven to nine hours after the work is done. Cut the sleep, and the work does not bank.
The fifth is the most important. The window does not close. Andy is unequivocal. The vast majority of cyclists over 40 are nowhere near their genuine ceiling. They have a training history weighted heavily toward endurance volume, light on power, light on strength, light on recovery structure. When the missing pieces are added, performance moves forward — not less slowly, forward. The "Not Done Yet" framing this audience already knows is not a slogan. It is the actual physiology.
Why This Episode Matters
There is a reason this conversation lands so hard for the Roadman audience. Most masters cycling content is either resigned ("manage your decline") or motivational without substance ("you've got this"). Andy refuses both. He treats the masters cyclist as an athlete with a specific physiological problem and a specific list of interventions that solve it. The interventions are not exotic. They are velocity-aware resistance training, sport-specific neuromuscular work on the bike, real protein dosing, and a sleep and stress structure that lets the body bank what it earns.
For the rider in their forties or fifties who has been doing the same training for a decade and watching the numbers slide, this is the most actionable conversation we have run on the podcast this year. The work to do is not more. It is different.
If you want to actually test whether you have lost the high end yet, run your numbers through the Masters FTP Benchmark and Masters Recovery Score — they are the two tools we built specifically for the cyclist Andy is describing in this episode.
CLAIMS FROM THIS EPISODE
Each tagged with the strength of evidence behind it.
STUDY
Power output declines at a faster rate than maximal strength after age 40, and strength declines faster than muscle mass — the neuromuscular system ages first.
Source: Skelton et al. (1994), Reid & Fielding (2012), Mitchell et al. (2012) on age-related neuromuscular decline
STUDY
Type II (fast-twitch) muscle fibres shrink 10 to 40 percent in older adults compared to younger controls, while type I fibres are relatively preserved.
Source: Lexell et al. (1988), Nilwik et al. (2013), reviewed in Wilkinson et al. (2018)
STUDY
Velocity-based resistance training preserves type II fibre function and rate of force development more effectively than slow-tempo heavy lifting alone in masters athletes.
Source: Pareja-Blanco et al. (2017), Casas-Herrero et al. (2022) on power training in older adults
STUDY
Daily protein intakes of 1.6 to 2.2 grams per kilogram, distributed across four meals with a leucine-rich dose post-exercise, support muscle protein synthesis in adults over 40 more reliably than lower or front-loaded intakes.
Source: Moore et al. (2015), Morton et al. (2018) ISSN/JISSN protein position stands
STUDY
Masters athletes who add targeted resistance and power work to a polarised endurance base improve cycling efficiency and anaerobic power without negative effects on VO2max.
Source: 2025 European Journal of Applied Physiology meta-analysis (17 studies, 262 trained cyclists)
“Power is the canary in the coal mine for ageing. Long before muscle mass falls off a cliff, the speed at which you can produce force has already started to drop. If you only train slow, you are training the part of the system that is already going to be fine.”
“Type one fibres mostly take care of themselves in an endurance athlete. Type two fibres do not. They will quietly shrink for ten years while you keep telling yourself that the riding is enough.”
“Velocity is the variable most masters athletes ignore. Moving a moderate weight fast does more for the nervous system than moving a heavy weight slowly. Speed is a skill, and like any skill, you lose it if you stop practising it.”
“Recovery is not the absence of training. It is the active process that turns training into adaptation. Cut sleep, stack stress, and under-eat protein, and you are running a body that cannot bank what you are spending.”
FREQUENTLY ASKED QUESTIONS
What is happening to muscle after age 40 that affects cyclists most?+
Galpin describes a hierarchy of decline. Muscle mass falls roughly 8 percent per decade after 40, but strength falls faster than mass and power falls faster than strength. Type II (fast-twitch) fibres shrink first and shrink hardest, often 10 to 40 percent smaller than in younger controls. Type I (slow-twitch) fibres are relatively preserved. That is why most cyclists keep their endurance well into their fifties but lose the kick on a climb, the surge out of a corner, and the ability to respond to an attack. The fitness is intact. The fast-twitch machinery is not.
Why is endurance training alone not enough for cyclists over 40?+
Endurance riding largely recruits and trains the slow-twitch fibres that age well anyway. Without explicit high-velocity work — sprints, neuromuscular efforts, and resistance training that demands rapid force production — the type II fibres that drive power continue to atrophy. Galpin's argument is that the cyclist who only does steady miles is training the fibres that need it least and ignoring the ones that need it most.
What does Galpin recommend instead of just adding more bike volume?+
Two strands of work. First, sport-specific resistance training that includes single-leg movements, controlled eccentrics, and velocity- based loading where the bar moves fast under moderate load. Second, neuromuscular work on the bike — short sprints, low-cadence efforts, and standing accelerations that force fast-twitch recruitment. The combination protects the fibres and the neural drive that activates them.
How much protein do masters cyclists actually need?+
Galpin sits in the 1.6 to 2.2 grams per kilogram per day range for training masters athletes, with a clear preference for distributing it across four meals rather than loading at dinner. At least one dose should sit above 35 grams to clear the leucine threshold for older muscle. Most serious amateur cyclists eat closer to 1.0 to 1.2 grams per kilogram and front-load the lower end at lunch and breakfast.
Is it possible to get faster after 40, or just slow the decline?+
Galpin's position is that most cyclists over 40 are nowhere near their genuine ceiling. The training history of the average masters amateur is heavy on endurance volume and light on power, strength, and recovery work. Adding what has been missing — targeted resistance, velocity work, real protein dosing, and a recovery structure — produces forward progress in the data, not just slower decline. The window does not close. The training has to change.
NEVER MISS AN EPISODE
Weekly insights from the podcast. The stuff that actually makes you faster.