Man in his 50s doing a farmer's carry with dumbbells in a gym

Most men over 40 notice it at some point. The stairs feel steeper than they used to. Getting up off the floor takes a grunt and a hand on the couch. You used to carry all the groceries in from the car in one trip. Now you make two, and you’re breathing hard by the top of the stairs.

Most of us shrug and blame age. Or our heart. Or “being out of shape.” Then we leave it there.

Dr. Andy Galpin has a better answer, and it’s good news. Galpin is a scientist who studies how muscles work and how they change. He has a PhD in exercise science. He started a muscle research lab at Cal State Fullerton. He also used to compete in weightlifting, so he isn’t just a lab guy. In this interview with Tom Bilyeu on Health Theory, he explains why we get weaker as we age, which part of our muscle goes first, and what kind of exercise keeps it.

Below are the most useful ideas from that talk for men 40 and up. We also added a few real studies that back them up. The quotes are his words. The simple explanations around them are ours.

It’s Not Your Heart. You Got Weak.

Why you get winded on the stairs as you age

Galpin asks a simple question. Why does someone get out of breath walking up the stairs as they get older?

Most people would guess it’s the heart or the lungs. Or they’d say they just have “low energy.” Galpin says no:

“It’s not because their mitochondria suck. It’s not because they can’t produce energy, ’cause that’s not an energy-demanding activity. It’s because they got weak.”

(Mitochondria are the tiny “engines” inside your cells that turn food and oxygen into energy.)

Here’s what he means. Walking up one flight of stairs doesn’t burn much fuel. But it does take legs strong enough to push your whole body up, one step at a time. Picture two men who both weigh 200 pounds. One has strong legs. For him, each step is easy, like lifting a light box. The other has weak legs. For him, each step is like lifting a heavy box. Same stairs, but the weaker man is working close to his limit. So his heart pounds and he gets winded.

The pounding heart and the heavy breathing are the signs. Weak legs are the cause. Galpin says if you only look at the signs, “you’re looking at the wrong thing.” Of course, if you get chest pain, dizziness, or you’re short of breath when you’re resting, that’s not a strength problem. See a doctor.

What actually changes in your muscles after 40

Your muscles aren’t all one thing. They’re made of millions of thin strands called fibers. There are different kinds of fibers, and they don’t all age the same way.

This is the key to the whole talk. It’s also why “just staying active” isn’t enough by itself. Walking the dog, mowing the lawn and easy bike rides are all good for you. Keep doing them. But they don’t really work the part of your muscle that disappears fastest as you get older. That part is explained next.

The Muscle Fibers You Lose With Age

Fast-twitch vs. slow-twitch in plain words

Galpin keeps it simple. There are “fast-twitch muscle fibers that produce force and strength.” And there are “slow-twitch muscle fibers that help you resist fatigue.”

Slow-twitch fibers are your “all day” fibers. They help you walk for an hour or stand at a barbecue all afternoon. They’re small. They don’t get tired easily. But they aren’t very strong.
Fast-twitch fibers are your “strong and quick” fibers. They’re what you use to stand up from a low couch, catch yourself when you trip on a curb, lift your grandkid up onto your shoulders, or carry a heavy cooler. They’re bigger and stronger. But they tire out fast.

Why heavy, hard work is the only way to keep them

This is the most important line in the interview:

“The fast-twitch muscle fibers are the ones that you lose with aging. And the only way to keep those things alive are to do high-force contractions. You can’t keep those alive any other way.”

A “high-force contraction” just means making a muscle work really hard. Think of pushing a stalled car, lifting something heavy, or climbing a steep hill fast.

Your body is smart, and it’s also lazy. It only uses fast-twitch fibers when a job is hard. Walking? Slow-twitch fibers can handle that. So if your days never ask for hard effort, your body figures it doesn’t need those big fibers. Little by little, they shrink. Galpin puts it bluntly. You can build all the endurance you want, but “you’re going to be weak.” And “that’s going to be a problem ’cause you can’t move yourself.”

Science backs this up. A 2013 study by Nilwik and others compared young men (about 23 years old) with older men (about 71). The older men had smaller thigh muscles. Almost all of that difference came from one thing. Their fast-twitch fibers were about 29% smaller. Then the older men lifted weights for six months. Their fast-twitch fibers grew by about 24%. That growth explained nearly all the new muscle in their thighs (Nilwik et al., 2013).

Read that again. These men were in their 70s. The fibers that shrink with age are the same ones that grow back when you lift. If you’re 60 and have never touched a weight, this is good news for you.

Muscle Is a Longevity Organ

Strength and how long you stay healthy

Galpin says his big goal is to live a long time. But not just to be alive. He wants healthy years where he can still do what he loves. He doesn’t want to be “just like alive but hating my life.” He calls this your “wellness span.” It’s the part of your life where you can still take a trip, get down on the floor with the grandkids, and carry your own bags.

When he lists what predicts a long, healthy life, muscle is near the top:

“Having a ton of muscle mass and having a bunch of strength is really, really, really critical to longevity, especially wellness span.”

The research agrees. A UCLA study looked at 3,659 older adults from a big U.S. health survey. The people with the most muscle for their height were about 20% less likely to die during the study than the people with the least muscle (Srikanthan & Karlamangla, 2014).

Strength shows the same pattern. A huge study tested the grip strength of 139,691 adults in 17 countries. Grip strength is how hard you can squeeze. They used a special handle that measures it. People with a weaker grip had a higher risk of dying from any cause, and from heart disease, over about four years (Leong et al., 2015).

One honest note. Studies like these show a link. They don’t prove that muscle alone adds years. But they all point the same way Galpin does. Being strong matters a lot for how long you stay healthy.

Muscle and blood sugar

Galpin made one more point that surprised the host. He asked, “Do you know what actually regulates blood glucose the most?” (Blood glucose is just the sugar in your blood.) His answer: “The fast-twitch muscle fibers.”

Those big fibers are the ones that are best at burning sugar for fuel. So when someone has trouble with blood sugar, the cause isn’t always the liver or the gut. In his words: “It also could be the fact that you don’t strength train. Those fibers are dormant and/or gone.” Dormant means asleep.

The good news is that sleeping fibers can wake up. Galpin says muscle can change “really rapidly.” That’s true even if you haven’t lifted anything heavy in years. Or decades. If you have diabetes or take blood sugar medicine, tell your doctor before you start. Exercise can change how much medicine you need.

The Exercise Matters Less Than You Think

Deadlift, leg press or stairs

A lot of men never start lifting. They think they need to learn fancy barbell moves, buy a gym membership, or hire a coach. Galpin says the exercise is just a tool:

“An exercise is simply an external stress… If you want to turn on the fast-twitch muscle fibers in your hamstrings and your glutes and your quads, I don’t care if you want to do a hex bar deadlift, if you want to do some squat, if you want to do a leg press machine, it doesn’t matter.”

(Hamstrings are the backs of your thighs. Glutes are your butt muscles. Quads are the fronts of your thighs. A hex bar, also called a trap bar, is a six-sided bar you stand inside of. It’s easier on most people’s backs than a regular barbell.)

What counts is how hard the muscle works. As he says, “The point is you need to be challenging the muscle’s ability to contract really hard.”

So what counts as “hard”? A simple test: by the last two or three reps of a set, it should be a real struggle to finish. But your form should still look clean. If you could easily do 10 more, it’s too light. If your back rounds or you have to jerk the weight up, it’s too heavy.

Simple options for beginners or bad joints

Galpin says you don’t even need weights at first, depending on how strong you are. He mentions a “single leg squat perhaps, with no weight at all… or maybe some stairs.”

Let’s say you’re 58 and haven’t worked out in 20 years. Try this. Sit in a kitchen chair. Stand up without using your hands. Sit back down slowly. Do that 10 times. If the last few are tough, that’s real strength training for you right now. When it gets easy, hold a jug of water. Later, try it on a lower chair. Then try a step-up onto a sturdy stair.

Worried about your back or knees? That’s normal. Start lighter than you think you need. Move slowly and with control. Pick exercises that feel okay, like a trap bar deadlift, a leg press machine, or carrying a heavy dumbbell in each hand. Some muscle soreness a day or two later is normal. Sharp pain or pain in a joint is not. Stop and switch to something else. If you have an old injury, a physical therapist can show you safe ways to train around it.

Galpin also warns against doing the same three exercises forever. “You’re probably not challenging all the muscle in enough of a variety, and that’s not sustainable over time.” Over a week, try to work your legs, hips, back, chest, shoulders and grip.

Stop Choosing Between Cardio and Weights

Galpin doesn’t love the word “cardio.” His problem is that it splits people into two camps. As he puts it: “either I jog for an hour or I go lift weights. Like, that’s it?” Most men pick one and skip the other. Galpin wants you to do both, and a bit of other stuff too.

Why VO2 max predicts a long life

Besides muscle, Galpin names VO2 max as one of the biggest signs of a long life. VO2 max sounds technical. It just means how much oxygen your body can take in and use when you’re working as hard as you can. In his words, it’s “the most amount of oxygen you can bring in and utilize.” Think of it as the size of your engine.

He explains it as a chain. First your lungs pull in air. Then your heart and blood vessels carry the oxygen to your muscles. Then your muscles grab the oxygen and use it to make energy. If any link is weak, your engine is smaller. And one of those weak links can be weak muscles. That’s another reason strength and cardio go together.

The research here is strong. Doctors at the Cleveland Clinic looked at more than 122,000 adults who did a treadmill test. They followed them for about 8 years. People with low fitness had a much higher risk of dying. The risk was as big as, or bigger than, the risk from smoking, diabetes or heart disease. The fittest group had about one-fifth the risk of the least fit group. And the researchers found no point where more fitness stopped helping (Mandsager et al., 2018). This was true for people over 70, too.

You don’t need a lab test to know where you stand. If climbing two flights of stairs or a short hill leaves you gasping, your engine has room to grow. The good news from that study is that fitness is something you can change.

Unpredictable movement like grappling

Galpin also wants people to add movement that isn’t just up-and-down and controlled, like most gym exercises. He gives an example: “Things like martial arts and grappling are a fantastic way to get this non-controlled, non-specific movement in, which is very, very important… on overall physical health.” (Grappling is wrestling-style fighting, like jiu-jitsu.)

No, you don’t have to start jiu-jitsu at 58. Although plenty of men your age do. The point is to do something each week where your body has to react, twist, catch and adjust. That could be a pickup basketball game, hiking a rocky trail, playing catch, or chasing your grandkids around the yard. Real life isn’t neat and controlled. A slip on ice or a stumble off a curb isn’t either. This kind of movement trains your body for those moments.

Galpin’s 3-Part “Bulletproof” Formula

The host asked what someone who wants a long, healthy life should do. Galpin laid out a simple mix of three things. He said that if you do them “in a progressive fashion, in a planned order,” then “you’d be about as bulletproof physically as you could possibly be.”

1. Steady cardio at about 80% heart rate

This is about how long you can keep working hard without stopping. Galpin is clear that it’s not a slow four-hour hike. It’s “an elevated heart rate at, say, 80%. How long can you go? 20 minutes? 25? 30? 40?”

What does 80% heart rate mean? It’s 80% of the fastest your heart can beat. A common rough guess for your top heart rate is 220 minus your age. That’s a rule of thumb, not Galpin’s number. So for a 55-year-old, it’s about 165 beats per minute. 80% of that is about 130. A cheap fitness watch or a chest strap will show you your heart rate. No watch? Use the talk test. At this pace, you can say a few words, but you couldn’t hold a normal conversation. Brisk uphill walking, rowing, or biking all work. If you take heart or blood pressure medicine, some of them slow your heart rate, so the math won’t fit. Ask your doctor what’s right for you.

2. Short, very hard intervals

Intervals mean short bursts of hard work with rest in between. Galpin describes this as “a shorter, extremely high physical challenge. So something like interval training. But really, really, really difficult.”

For example, pedal a bike as hard as you can for 20 to 30 seconds. Then pedal easy for a couple of minutes until your breathing settles. Repeat that four to six times. You could also walk fast up a steep hill, then walk back down slowly. Don’t start here if you’ve been inactive for years. Build a base first with a few weeks of steady cardio and strength work, and get your doctor’s okay.

3. Strength training

This is the part that keeps your fast-twitch fibers alive. It means hard work for your legs, hips, back and upper body. That could be weights, machines, kettlebells, or your own body weight.

A sample week for a man over 40

Galpin didn’t give a set schedule in the interview. In fact, he said he doesn’t believe in one routine that fits everyone. So here’s one simple way to put his three parts into a week. This is our example, not his.

The strength days are based on a big report from the National Strength and Conditioning Association (NSCA), a group of strength coaches and scientists. The report says lifting is “a powerful intervention” against losing strength, muscle and independence as we age. It recommends lifting 2–3 times per week. It also says programs can be adjusted for people who are frail or have health problems (Fragala et al., 2019).

Monday – Strength (whole body): trap bar deadlift or leg press, push-ups or a dumbbell press, rows, and farmer’s carries (walking while holding a heavy weight in each hand).
Tuesday – Steady cardio: 20–30 minutes of brisk uphill walking, biking or rowing at your 80% pace.
Wednesday – Easy day: a walk, some stretching, or something playful like catch with the grandkids.
Thursday – Strength (whole body): different moves from Monday, like goblet squats (holding one weight at your chest) or step-ups, an overhead press, pulldowns, and kettlebell swings.
Friday – Hard intervals: after a good warm-up, 4–6 hard bursts of 20–30 seconds, with full rest in between.
Saturday – Longer cardio or a sport: a hike, a bike ride, or a pickup game.
Sunday – Rest.

Does that look like too much? Then start small. Two short strength days and one walk a week is a great start. Each session can take 30 to 45 minutes. Add more once it feels normal. How long until you notice? Most people find the exercises feel easier within the first few weeks, partly because the body learns the moves. Bigger changes in muscle take months. In the Nilwik study above, the men trained for six months. Stick with it.

Why Adding 5 Pounds Every Week Stops Working

Muscles only keep getting stronger if you keep asking them for a little more over time. Coaches call this “progressive overload.” It’s a fancy name for “make it a bit harder as you get stronger.” Galpin says you have to do it. But he also points out the problem with the simplest version: “You can’t just simply say, ‘Okay, I’ll just add 5 lb to the same movement every time.’ How long does that last? Not very, right?”

He’s right. If you added 5 pounds a week to your deadlift, you’d be adding 260 pounds a year. Nobody keeps that up. Sooner or later you hit a wall. Pushing past it is how many men over 40 get hurt.

Variety with a plan

Galpin’s answer is variety, but planned variety. “There’s a difference between variation in our training and randomization… Randomization is not a good idea. There’s no plan, there’s no purpose.”

Random looks like this: you walk into the gym and use whatever machine is free. Galpin jokes about doing an exercise “’cause that machine is open.” Planned variety looks different. You change exercises on purpose, in a set order, so you keep getting stronger without wearing out the same joints. A simple way to do it: write down your workouts. Use the same plan for about four to six weeks. Then swap in a few new exercises for the same muscles.

Other ways to progress

Adding weight is only one way to make things harder. When the weight gets stuck, you can:

Do one or two more reps with the same weight.
Add one more set.
Lower the weight more slowly, taking three or four seconds on the way down.
Switch to a harder version of the move, like going from two legs to one leg, or from a leg press to a trap bar deadlift.
Rest a little less between sets.
Swap in a new exercise for the same muscles every few weeks.

Any of these counts as progress. You don’t need a bigger number on the bar every week to be getting stronger.

The Biggest Change Isn’t a Workout

Fragility and unplanned stress

Galpin says he doesn’t want people to be “fragile.” He explains what he means: “If you can’t handle an unplanned stress in any aspect of your life, and a little bit of stress causes a big problem, that to me is fragile.”

Think about what that looks like for a man over 50. Fragile is when you lift a bag of mulch the wrong way and you’re laid up for a week. Or you slip on the ice and can’t catch yourself. Or one long day helping your kid move leaves you wrecked for three days.

Galpin’s fix is to stress your body on purpose, in small, planned doses. Then the unplanned stuff doesn’t knock you over. That’s exactly what strength training does. When your body is used to hard work, a heavy box or a long day on your feet is no big deal.

Taking responsibility

At the end, the host asked Galpin for the one change that would help people’s health the most. His answer wasn’t an exercise at all:

“I would have to say accept responsibility… it may not be your fault, but you have options.”

He knows some people got bad luck. Bad genes, a bad back, a hard life. He talks about this too. “What are you going to do about it? You still have an option. You still can have some control. But you have to make that choice.”

That’s not blame. It’s the opposite. It means you aren’t stuck. Whatever shape you’re in today, at 45 or 65, the next step is still yours to take. For a lot of men, that may be the most important line in the whole interview.

FAQ

Is it too late to start at 50 or 60?

No. Galpin says muscle can change “really rapidly,” even after weeks or decades without hard training. In the Nilwik study, men around 71 years old grew their fast-twitch fibers by about 24% after six months of lifting (Nilwik et al., 2013). The NSCA report also says lifting can be adjusted for people who are frail or have health problems (Fragala et al., 2019). So if you’re 60 and have never lifted, this is for you. Start with your own body weight, like the chair stand above, and build up from there.

How heavy is heavy enough?

Galpin didn’t give a number. His test is whether you’re “challenging the muscle’s ability to contract really hard.” In real life, a weight is heavy enough when the last two or three reps of a set are a real struggle, but your form still looks good. For a beginner, that might be a chair stand. For someone who’s been lifting a while, it means real weight on the bar. The NSCA report says healthy older adults can work up to fairly heavy loads over time, about 70–85% of the most they can lift one time (Fragala et al., 2019). “Work up to” is the key part. Start light, learn the move, and add weight slowly over weeks.

How many days a week?

The NSCA report recommends lifting 2–3 times per week for older adults (Fragala et al., 2019). Add one or two steady cardio days. Once you have a base, add one short interval day. That covers all three parts of Galpin’s formula, and it fits in about three to four hours a week.

The Bottom Line

Getting weaker after 40 isn’t just “getting old.” A big part of it is losing your fast-twitch fibers. Those are the strong, quick muscle fibers that you only keep by doing hard work. The fix isn’t fancy. Lift something challenging two or three times a week. Push your heart with steady cardio and a few short, hard bursts. Add some playful, unpredictable movement. And take charge of the part you can control.

Do that, and carrying the groceries up the stairs, getting up off the floor, and keeping up with your grandkids can stay easy for a long time.

Ready to get started? These guides can help:

Talk to your doctor before you start a new exercise plan. This is extra important if you have heart problems, high blood pressure, diabetes, joint problems or an old injury, or if you haven’t exercised in a long time. This article is for general information only and isn’t medical advice.

Why Men Get Weak After 40, and the One Kind of Training That Stops It