Why You Get Slower With Age and What to Do About It

Struggling to hit your usual paces in biking, running or another cardio activity as you age? This is a common occurrence as we get older, but that doesn't mean there's nothing you can do about it.

A January 2018 statistical analysis in the ‌Review of Economics and Statistics‌ found that runners can maintain peak speed through age 40, and that even after age 40, they only slow at a rate of about one percent each year through their 70s. After reaching age 70, the decline increases to 2 to 3 percent.

So it's unlikely you'll wake up one day and have drastically lost your physical fitness as a result of aging. Still, there are a variety of ways to recognize this slowdown and take steps to delay it and stay healthy.

Tori Dippold an exercise physiologist in Colorado, notes that there are many factors that can contribute to a slowing in aerobic performance as we go gray.

"One of the biggest contributors [to slowing down as we age] is a decrease in VO2 max, or the body's maximal ability to utilize oxygen," Dippold tells LIVESTRONG.com. "VO2 max is one of the greatest predictors of endurance performance no matter your age."

VO2 max — an abbreviation for volume (V) of maximum (max) oxygen (O2) — tells us how well a person utilizes the oxygen they intake with each breath. When VO2 max decreases, your body is able to utilize less of the oxygen that is breathed in, thus limiting muscle output and cardiovascular function.

According to a small August 2016 study published in ‌PLOS One‌, VO2 max declines as we age, which makes it difficult to maintain the same level of fitness, speed and strength we once had in our younger years.

The older we get, the lower our maximum heart rate may be, which can decrease how intensely we are able to exercise, Dippold says. A max heart rate is the upper limit of heartbeats per minute that your body can safely sustain.

You can calculate a rough estimate of your max heart rate with this formula from the American Heart Association: 220 - [your age] = estimated max heart rate.

For example, a healthy 30-year-old would have a max heart rate of 190. Roughly, the maximum rate their heart is going to beat is 190 beats per minute (bpm). Be sure to check with your doctor to account for unique factors — like heart disease or past illness — that may impact your specific max heart rate calculation.

Each time your heart pumps, it sends a specific volume of oxygenated blood away from your heart to be used by your body. This is called heart stroke volume. With time, your heart's stroke volume decreases as your heart naturally becomes weaker and less efficient with age.

"Essentially, as we age, our heart is beating at a lower rate per minute, and with each beat, less oxygenated blood is being pumped out to our muscles," Dippold says. "These factors cause a steady decrease in your body's ability to use oxygen efficiently with each passing decade."

Less oxygenated blood in your muscles means muscles fatigue faster and more easily, leading to decreased speed and responsiveness in athletic activity, according to a small September 2015 study in the ‌American Journal of Physiology: Regulatory, Integrative, and Comparative Physiology‌.

Hormones also play a role in seeing our paces slow as we get older. Dippold explains that decreasing testosterone and estrogen levels can affect lean muscle mass and the speed of your metabolism.

The onset of menopause can lead to difficulties in maintaining muscle mass. During menopause, there is a decline in estrogen and progesterone production. This lessening of those two key hormones can lead to decreased muscle protein synthesis, according a June 2019 review in ‌Bone‌, which may result in a person going through menopause struggling to maintain lean muscle mass.

Regardless of gender, it's common for older adults to see a reduction in muscle mass as their testosterone or estrogen production drops off. This can result in a reduction in not just lean muscle mass, but in muscle explosivity (the force with which you might push off with each run stride, for instance) and strength, according to Dippold.

Not all pace slowdowns are related to physiological changes. Some come from the daily stressors of life. Nagging injuries from the past, decreased motivation to train for any number of reasons and life responsibilities, such as family and a job, can lead to less time to maintain aerobic fitness.

Life stress can also result in increased cortisol levels. Cortisol is the body's stress hormone and increases when stress levels are high. According to the Mayo Clinic, cortisol can lead to excessive muscle tightness, sleep problems, weight gain and heart disease when left unchecked. All of this may be related to physical slowdowns, too.

Fortunately, a blood, urine or saliva test can determine your current cortisol levels, according to the Cleveland Clinic. Check with your doctor about being tested for elevated cortisol if stress is a chronic concern.

"The short answer is 'no,'" Dippold says. "This slowdown is inevitable with age. However, managing stress, training smart and taking care of oneself can help combat the slowdown."

Eventually, no matter how healthy and fit someone is, they'll see their aerobic paces, weightlifting abilities and top-end speed decrease. This is normal and to be expected — as is gaining wisdom along the way.

"Despite losing some speed and athletic ability, we gain experience over the years," Dippold says. "[Working out] for years can lead a person to be very in tune with their body [and able to tell] when they might be a little out of shape or abnormally fatigued."

Dippold recommends having regular annual physical doctor's appointments with a primary care physician or cardiologist. And there's "never a bad time" to get a baseline of your heart function and capacity, she says.

Fortunately, there are steps to take to manage (or even delay) an age-related slowdown when it comes to physical activity.

Dippold's top suggestion for those looking to combat slowing down as we age is to prioritize recovery after workouts.

"Building in rest and recovery days with your workout schedule will allow you to workout harder on the other days," Dippold says. "Recovery days not only give muscles time to repair themselves from natural workout-induced wear and tear, but they also prevent injury and prevent the immune system from becoming overworked."

The World Health Organization defines stress as "any type of change that causes physical, emotional or psychological strain. Stress is your body's response to anything that requires attention or action." If you've had a particularly stressful work day, consider stepping back from a run that day, too, and let your body's cortisol levels decrease. This can help with longevity in sport and with mental wellness.

As life gets busier and responsibilities mount, it is easy to forget to take care of ourselves on a basic level: eating well, hydrating enough and sleeping for at least seven hours a night.

Understandably, it can be difficult to achieve those three things all day, every day. Sometimes, life gets in the way.

On the whole, though, strive to eat a balanced diet, prioritizing lean protein, fruits, vegetables and healthy fats. Avoid overly salted and sugared foods along with processed foods. Eating well can help sustain lean muscle mass, joint health and prevent heart disease.

According to the Mayo Clinic, people should aim to consume about 12 cups to 15 cups of water a day, on average, which comes out to about 91 to 125 fluid ounces.

Lastly, aiming for at least seven hours of sleep each night is recommended by the Mayo Clinic. A March 2015 study published in ‌MEDtube Science‌ concluded that sleep is when your body "reorganizes and recharges itself," among other key activities, assisting with longevity and overall wellbeing.

Adding in strength and mobility moves to your workout regimen can be a great way to maintain muscle mass and keep tissue and joints limber.

Tracy Green, a certified Pilates instructor and running coach in Louisville, Kentucky, highly recommends making strength and balance work a regular part of any aging athlete's life. She frequently works with clients who are over the age of 50 and want to maintain — or gain — fitness as they age.

"Any sort of single leg–focused balance and strength work is [ideal for athletes as they age]," Green tells LIVESTRONG.com. "We tend to lose some of our balance abilities as we age, so working on exercises that reinforce good balance and proprioception is great for both exercising and daily life."

Green recommends three moves to help balance.

Green is a strong advocate of staying in the present in order to find joy in exercising.

"Avoid the comparison trap — not just with other people in your community or at a race, but with yourself," Green says. "Set realistic goals that align with where you're at now, not who you were in the past."

To further avoid comparison (which is the thief of joy) Green suggests choosing races, gyms or training venues that bring you excitement and happiness. It's more likely that you'll do your best and forget about arbitrary metrics when you're in a space that makes you smile.

Lastly, Green advises that while many goals center around time or pace, they don't have to.

"What other measures of success can you look to in your training?" Green says. "For example, did you work out with friends or make a new friend while working out? Or did you make it a point to commit to trying something new, like a new exercise at the gym or signing up for a new race? It's not always about how fast you go or in what place you finish at a race."

Take time to think about why leading an active lifestyle is important to you, then form goals from there. Although pace and speed may slow down with time, it doesn't mean that joy in leading a healthy life has to diminish.