Runners love numbers. Whether it's pace, finishing times or resting heart rate, we view figures as a sign of our progress, accomplishments and dedication to the sport. So it's no surprise that many of us struggle with one number that increases each year, regardless of how hard we train: our age.
But thanks to all the health benefits that running brings, you don't need to sweat each time a candle is added to your cake. "There's a big difference between biological age, or how old your body thinks you are, and chronological age - how old the calendar says you are," says Steven Hawkins, professor of exercise science at California Lutheran University in the US. "The biological ages of runners are at least 10 years younger than their chronological ones, and this gap widens with time."
To help you keep that biological clock fooled, Runner's World takes a look at the life span of a runner, decade by decade, with advice from medical experts, trainers, nutritionists and amazing runners who define peak performance.
Teens: Decade of innocence
Runners in the throes of puberty have superpowers. A British study compared 12 boys and 13 men doing 10 sets of 10-second sprints. The boys sustained their power output better than the men, partly because teens regenerate creatine (a compound that supplies muscles with energy) quicker than older runners. Also, levels of lactate, the by-product of intense efforts, are naturally lower at this age.
Girls share the same ability to crank up the power - and can sustain it even better than boys. Japanese researchers found that in a series of sprints, teenage girls lost 10 per cent less power than boys the same age did. That said, as muscle mass piles on, boys have the distinct upper hand - or in this case, leg. "Proportionately, boys develop more muscles than girls do and have a natural power advantage," says Professor Cameron Blimkie of McMaster University in Canada.
Bones are still developing, too, and running helps make them as dense as possible. Blimkie's study on the bone density of female runners, triathletes, cyclists and swimmers found that runners had the highest bone-mineral density and strength.
You may be fit, but your growing body still needs to be handled with care. Bones develop faster than their supporting ligaments and tendons. As a result, joints and muscles can be prone to injury. "Some teenage female athletes get a condition called amenorrhea, which is when their regular periods stop. This can have significant implications," says Dr Jo Wallace, a lecturer in exercise physiology at Aberystwyth University. "It happens when they're training hard but aren't consuming enough calories. This causes their oestrogen levels to drop, leading their periods to stop. This can be serious, as oestrogen is needed to build healthy bones. But once girls with amenorrhea start to have a sufficient food intake, the periods will return as normal."
Wallace advises both girls and boys to not take on too much mileage, and points out that if they do get an injury, should give themselves enough recovery time: "When bones are still growing at this age, the tiny microfractures that occur naturally are increased through exercise. For most people, this is a good thing as it increases bone density in preparation for later life, when they start to deteriorate. But at this young age, there's the risk that microfractures can develop into hairline fractures, which can then turn into more serious injuries."
Work on building your form and endurance so you can become a balanced, injury-free runner further down the road. Practise sprint-specific drills such as high knees and skips to build a strong foundation, ideally under a coach's supervision. "If an athlete has good form during the early years, that helps so much with performance and injury prevention later," says coach Greg McMillan (mcmillanrunning.com). Boost aerobic capacity by upping long runs by five minutes weekly. Go by minutes, not miles - and when in doubt, take it slowly. "Not every training run should end with your hands on your knees," McMillan says.
"For healthy bone development, calcium-rich foods such as milk, yoghurt and cheese, together with exercise such as running, will build up the peak bone density for later in life," says Wallace. "But you also need to maintain sufficient energy levels for the activity you are doing by eating your protein and carbs too. Remember that your metabolism will increase as you do more exercise.
"Calories are important for maintaining fat levels, and fats help release the fat-soluble vitamins A, D, E and K, which are essential for the repair of body cells."
18, from Coventry
"I've been running since I was seven years old. When I was 11 I joined Coventry Godiva Harriers, where coaching made me faster. I went on to win the English Schools' intermediate 800m title twice, and in 2008 I was invited to join the Aviva-sponsored On Camp With Kelly mentoring and education initiative, led by Kelly Holmes.
"In my GB vest at last year's IAAF World Youth Championships I won a bronze medal and set my 800m PB (2:03.83).
"I had a setback this season when I damaged my ankle by twisting it badly while training - but it's been my first injury, and I'm getting back into it now.
"I normally train six times a week with more mileage work in the winter and more quality speed sessions in the summer. Even after a tough session, I feel fine the next day - as long as I've had a good night's sleep."
20s: Decade of invincibility
"From a physiological viewpoint, you really are at your peak in your 20s," says David Jones, professor of sport and exercise sciences at Birmingham University. "Although women reach their natural shape and size in their mid teens, men are still growing and building muscle mass in their early 20s, and will reach their optimum before they're 30.
"As muscles bulk up, the tendons enlarge to cope with the extra load. If you're training hard, your muscles will be slightly stronger than the average person's, and you will certainly have a better blood supply to the muscles. Your VO2 max - the amount of oxygen your body can consume while exercising - will be at its full potential too.
"Bone density also reaches its peak in the early 20s for men - a few years after it has peaked in women - and it remains constant during this decade."
You may start to feel twinges in your knees towards the end of your 20s. Cartilage, the gel-like, shock-absorbing substance that lines the ends of your bones, can become frayed as your 30th birthday looms.
Also, "young, unsupervised athletes usually don't get enough sleep, hydration or adequate nutrition," says Bradley Young, a sports psychologist at the University of Ottawa, Canada. "At some point, often seven or eight years after leaving school, you realise that you can't stay up until two o'clock in the morning and belt out an eight-mile tempo run the next day. You eventually learn to self-regulate to save yourself from becoming a post-education running casualty."
Your most important training tool this decade? Self-control. Cardiovascularly, you're a rock star, but your musculoskeletal system can't always keep up with your heart and your lungs. "The demands and impact of running are too intense on your joints and muscles to complete tough workout after tough workout without getting injured," says McMillan. He recommends taking at least one easy day between hard runs and incorporating impact-free cross-training activities into your routine.
"Runners in their 20s tend to either eat poorly or eat just to get by; they don't make the connection between food and performance," says running nutritionist Lisa Dorfman, author of The Vegetarian Sports Nutrition Guide (£12.99, John Wiley & Sons).
When you're running, you want your body to tap into easily accessible carbs for fuel, not drain your protein stores. "Protein aids muscle repair, boosts your immune system, maintains healthy hair and skin, and manages hormones and water balance," says Dorfman.
Before any run that exceeds an hour, eat about 40g of carbs (240ml of sports drink and half a banana). If you're going longer than 90 minutes, restock your carbs every hour with 470ml of sports drink or with a gel and some water. Within an hour of finishing your run, jump-start your recovery with a carb and protein snack (chocolate milkshake and toast, or a smoothie).
28, from Leeds
"I ran cross-country and middle distance at school, but in my late teens I stepped up to 5K and 10K. I’m sure all the running helped change my body shape from skinny to more bulky. In 2003, I did the Great North Run in 1:06:28, which was a real breakthrough for me, and I’ve now won the Midlands Cross Country title four times.
“I run about 90 miles a week and my training is very structured, but I’ve suffered with stress fractures to my foot, which has been frustrating. I eat loads of carbs, but quickly burn them off – and although I don’t have the perfect diet, I eat more good food than bad. I want to improve my PB at 5K (13:56) and 10K (29:04) while youth’s on my side.”
30s: Decade of the balancing act
Natural strength peaks during this decade. "Over time, runners' bodies learn how to build and efficiently recruit the key running muscles," says Tim Noakes, author of Lore of Running (£19.99, Human Kinetics Europe). That means that over distances of 10K and longer, you can clock consistent times until you're 35, regardless of how you train.
"After that, you can't rely on your age to predict your speed," says Hirofumi Tanaka, associate professor of kinesiology and health education at the University of Texas, US. "The amount and intensity of your training becomes crucial."
If you run marathons, you've found your tribe at the races: the average age of UK marathoners is 38. There's no doubt that a set training schedule adds structure to your otherwise chaotic life, but there's another good reason 30-somethings gather to run 26.2 miles: fast-twitch muscle fibres, used for sprinting, are lost before slow-twitch fibres, making it easier for you to go for distance rather than speed as you age.
That roll that's hanging over your running shorts? Sorry, but you can't blame it on your slowing metabolism. It's more likely to have been caused by too many trips to the takeaway and not enough to the track. Yes, metabolism slows a bit naturally; daily, you need on average 120 fewer calories aged 35 than you did at 25.
But what really causes metabolism to slam on the brakes is less lean body mass (because you're not strength-training) and less activity (because you've cut your mileage). Adding a tempo run and some resistance training on top of your regular runs would be ideal. You could also gradually up your mileage to maintain your weight. Researchers the University of California at Berkeley, US followed 5,000 male runners under the age of 50. The average six-foot-tall runner gained 3.3 pounds per decade. To offset the gain, the researchers recommend running an extra 1.4 miles per week. If increasing your mileage isn't an option, do more cross-training and eat less.
You may be changing a nappy with one hand and firing off emails with the other, but unless you also want to add nursing an injury to your to-do list, don't neglect strength-training. Not only does it prevent sprains and strains by building up connective tissues around your joints, but resistance training also increases your running economy by lowering the amount of oxygen you need to reach a certain speed. Don't worry - you don't need to join a gym. Just do two sets of 12 lunges, squats, calf raises, hamstring curls (with a stability ball), core work (plank position and sit-ups on a stability ball) and press-ups two or three times a week. On your runs, make the most of your limited time by periodically pushing the pace: do strides or tempo work.
To prevent the need to upsize your shorts, re-evaluate your calorie needs. Do this by first working out your basal metabolic rate (BMR) - the amount of energy your body needs to function:
men = 66 + (6.23 x weight in lb) +
(12.7 x height in inches) - (6.76 x age)
WOMen = 655 + (4.35 x weight in lb) +
(4.7 x height in inches) - (4.7 x age)
Then, to incorporate activity into your daily caloric needs, do the following calculation:
Little or no exercise: BMR x 1.2
Exercise 1-3 days per week = BMR x 1.375
Exercise 3-5 days per week = BMR x 1.55
Exercise 6-7 days per week = BMR x 1.725
Heavy exercise (twice per day) = BMR x 1.9
The figure shows how many calories you need a day to stay at the same weight. To lose weight, you need to take in fewer calories than this.
39, from Exeter
"I've been running since I was 13, but more as a way of keeping fit for my other sports: gymnastics and hockey.
"I started running competitively three years ago and realised I could usually get placed in local races with decent times. Last year I ran the Plymouth Half Marathon in 1:28, which gained me a championship entry at the London Marathon. I always had the base level of fitness, but doing more running has built up my endurance and I'm now much leaner.
"Although I've done an Ironman and some other triathlons in the past, I don't miss the cycling or the swimming training - but I couldn't live without running.
"I don't know if I can run much faster, but I really want to see how far I can go in the years ahead."
40s: Decade of new beginnings
You can continue to take pride in your resting heart rate, which barely changes as you age: though it declines by around 0.7 to one beat a year, its influence on your performance is minimal.
As with every decade, VO2 max continues to dictate how effectively you can push the pace. At least one element that determines VO2 max is out of your control: your heart's pumping ability naturally slows. However, you do have influence over three other factors: your muscle mass (the more muscle, the higher your max), body fat composition (the less fat, the lower it is), and training frequency and intensity (the less you push, the more it falls). This means you can offset the drop of your VO2 max with strength training and speedwork. The payoff? Not only can you reign over your local masters division, but you'll also surpass runners half your age. You also have a secret weapon: your hard-earned savvy. "People underestimate the cognitive part of running, but mental toughness isn't genetic, it's honed through experience," says Young.
Starting at 40, your kidneys are less likely to conserve water as you dehydrate, and the nerves in your mouth and throat that tell you you're thirsty don't function as well. So remember to hit the water stops in races and carry a bottle while training.
Bones start to deteriorate faster than they're forming, too. The loss hits women harder (from 30 until menopause, women lose one per cent density a year), but men aren't immune. Researchers studied the bone density of runners' spines and found that males had similar density losses to females. Take note: those who strength-trained had the best density scores.
"Your muscles still respond to training when you are much older, so 40 certainly isn't too old to start running," says Jones.
"But if you suddenly put your body under the enormous strain of training for a marathon, you're likely to suffer muscle and bone injuries, so build up gradually.
"If you've been running for years, don't always stick to the same training - you will get bored and your muscles won't get stretched."
"As you age, every calorie should be as nutrient-dense as possible," says Dorfman. Replace white carbs - bread, pasta and rice - with wholemeal versions. If you're starting to ache, especially in your knees, consider taking glucosamine and chondroitin supplements. Studies have shown that consuming 1,500mg of glucosamine and 1,200mg of chondroitin daily can ease joint pain.
49, from Cheshire
"I did my first marathon in London when I was 28, in two hours and 59 minutes. My marathon PB is 2:47, which I achieved aged 30.
"Throughout my 30s, I could run hard with relative ease and recover quickly too, but when I reached 40, I thought I should slow down and take more days off running. Consequently, my race times suffered.
"In my mid 40s I saw older runners racing well and realised I should have more in me yet. Over the last few years, despite injuries (torn calves and meniscus, which is in the knee) my training has become more structured and my performances have improved.
"I'm now running fast again, and my marathon time last year was 2:56. I've lost speed but my endurance is better and the will to perform well is still there. I know I should be getting slower, but I'm training harder in the hope that it won't happen."
50s: Decade of freedom
Even though you'll see your intervals get a bit slower regardless of your training, you can still maintain a strong showing at distance events. Young tracked a group of Canadian masters runners and found that while age predicted time for 1500m races, annual mileage, not age, determined speed over 10K. "This paints an optimistic picture for those who are motivated to do the work," says Young. "Consistent training lets you retain your performance."
Muscular strength peaks at around 30 but is "relatively well maintained" for decades to come, according to sports medicine specialist Tim Noakes. In one study of masters runners, 40-somethings and 70-somethings had similar leg power. After 70, it did decline - but 20 years later than it did in sedentary people.
Emotionally, you're much better off, too. Studies have shown that masters athletes are less depressed, angry and fatigued than those who don't exercise, according to Walter Bortz, author of Living Longer For Dummies (£12.99, John Wiley & Sons). Even better, Bortz conducted a study that found sexual satisfaction correlates with fitness level in those aged 50 plus.
"The average age for the menopause - when the menstrual cycle ends permanently - is 51," says Wallace. "At this time, women's oestrogen levels drop sharply, which can cause bone mass to drop by two to five per cent annually for the five years following menopause. This increases the risk of osteoporosis, a condition brought on by ageing where the bones become more porous and brittle because of a loss of minerals, mass and density. "By exercising and eating a healthy diet in your 50s, you reduce that loss," says Wallace.
Your sense of balance fades with age. "Go to a tai chi or yoga class, or practise closing your eyes and standing on one foot for 30 seconds," Bortz says. These activities can also strengthen your trunk muscles and prevent back pain.
Keep the spring in your step by doing plyometrics - jumping moves that strengthen your legs, help programme your central nervous system to respond quickly and improve mobility in your joints. Plyometrics might initially be too jarring, especially for those with joint issues, so start by using a skipping rope. Do one set of 10 jumps three times a week, working up to three sets. Then switch to jumping on one foot, beginning with one set, before progressing to moves like step-ups and step-downs.
Staying regular so you're not a fixture in the portable toilet line gets harder this decade, as your gastrointestinal tract naturally slows. Eat at least 15g of fibre daily - ideally, a combination of fruit, vegetables, beans, and wholemeal bread and cereal. "Fibre also helps manage blood-sugar and cholesterol levels, which are linked to diabetes and heart disease, and seem to creep up during your 50s," says Dorfman.
53, from Cornwall
"Many women my age worry about their shape, but I've never felt fitter, healthier or more toned.
"I enjoyed running at school, but only realised I had a talent for it in my 40s when I started winning local 5Ks, 10Ks and half-marathons that I'd entered for fun. One day a woman came up and congratulated me after a victory, before explaining she was an international selector. I got picked for England and have won medals at various distances and cross-country.
"In 2008, I took gold at the World Masters Half Marathon Championships with a PB of 1:23.
"I'm big on training smarter as I get older, and I always watch what I eat. I've learnt to listen to my body, so I gave up full marathons in 2003 after suffering from shin splints. Now, I stick to shorter distances and focus on fulfilling my goals."
60s: Decade of hanging tough
Your generation as a whole is getting faster. A study of the top 50 finishers in each age group of the New York City Marathon between 1983 and 1999 revealed that runners over 50 are significantly faster than they used to be. Overall performances of 20-somethings slowed over the 17-year span, and those of the 30- and 40-somethings plateaued. But men in 1999's 60-69 division were, on average, one minute and 14 seconds faster than men in 1983's 60-69 division, and women bettered their average by three minutes and 47 seconds.
If you have a family history of cardiovascular disease, keeping up with your speedwork might minimise your risk. A study of nearly 9,000 10K runners found that those who ran the fastest had lower blood pressure, and triglyceride and cholesterol levels than those bringing up the rear. Bone density loss for women also reduces to one per cent a year for the rest of their lives.
Previous sports injuries - especially those that didn't heal properly - may haunt you this decade. Osteoarthritis, which affects six million people in the UK, isn't a direct result of running, but of abnormal joints or bad alignment, primarily in the hips and knees. A Swedish study concluded that female football players who had an anterior cruciate ligament (ACL) injury over the past 12 years had a higher risk of osteoarthritis. But running can help. "You shouldn't rest," says Bortz. Exercise helps keep the cartilage between joints healthy.
Your stride length is shorter now, too. Studying 78 men at the seven-mile mark of a marathon, researchers found stride length of runners over 60 was 17 per cent shorter, on average, than those of 40-49-year-olds.
To lengthen your stride, stretch after every run, concentrating on your hamstrings, calves and lower back. "In general, the muscles in the back of the leg stiffen more," says Hawkins. In addition, McMillan suggests throwing some 10-15-second speed pick-ups into your regular runs to stretch out your muscles.
Running on soft surfaces and using a stationary bike or elliptical trainer can help you maintain your activity level if your joints start to feel creaky. And don't forget the weights: a study carried out by the Mayo Clinic in Rochester, US found that the stronger your quads, the more stable your kneecaps. What's more, quad strength protects against additional loss of cartilage behind the kneecap - and a stable knee that tracks properly won't wear down cartilage like abnormal joint movement does.
As your calorific needs continue to plummet, your need for nutrients doesn't cease - but your avenues for processing them do. "The mucosa membrane that lines your intestinal tract wears with age, so it doesn't absorb as well as it used to," says Dorfman. Take a daily multivitamin and make sure it has 100 per cent of the recommended B vitamins, which assist in cell growth and immunity. Probiotics (live, healthy bacteria found in Activia yoghurt and miso) also build up the mucosa membrane.
63, from Reading
My husband David and I ran the first London Marathon in 1981, only three years after I got into running. I did it in 4:18. I've now done 57 marathons - my fastest being 3:28 when I was in my mid 30s. I ran London this year in 4:59:43 and I've also run every Reading Half Marathon, peaking at 1:33 in 1987.
"I still try to run 30 miles a week, and although I've got slower over the years and take longer to recover from injuries, my pace has always been steady. I've moved my targets accordingly. I've always been very competitive and thought I'd stop when I went over five hours for a marathon, but still want to carry on. I get such a sense of wellbeing from my running, it's central to my life."
70+: The age of going and going
You'll probably be around to see your great-grandchildren run their first race. Researchers have concluded that regular physical activity decreases risk of cancer, cardiovascular disease and all other age-related causes of death by 25 per cent, increasing life expectancy by up to two years.
Even though the speed you consider comfortable has decreased, you're likely to be still outpacing your friends. A study in the Journal of the American Geriatrics Society reported that a faster walking speed correlates to a longer life span. Even if your quads and calves aren't as defined as they used to be, the fact that they're still strong is invaluable. "The most important body parts for keeping old people independent are the legs," says Bortz.
As you come into the next decade, you're likely to become a one-pace wonder - if you haven't already. "World-class masters over 70 spend more than 80 per cent of their training time running at one speed," says Young. "The training journal of a 72-year-old who ran a world record sub-three marathon showed very little speed or power work. The message is that athletes at this age can do amazingly well, in spite of their training. But perhaps there is the opportunity for better performance if they train more optimally."
You might find that your running shorts hit you a bit further down your leg. Between ages 30 and 70, men, on average, lose 3cm of height, and women lose nearly 5cm. By 80, men are down by about 5cm and women lose more than 7.5cm. "You may also lose a little lung capacity as you shrink because there's reduced space in your chest cavity," says Hawkins.
If a past injury hasn't already forced you to try pool running, do it now. With no impact on your joints and with all of the aerobic benefits of running, striding through the water at least once a week will help stave off any injuries lurking down the road. Try an interval workout: after a warm-up, go hard for one minute, easy for one. Repeat 10 times, then cool down.
Eat 70-100g of protein a day. People in this stage of life don't tend to get enough calories, meaning that protein intake, which keeps muscles functioning optimally, suffers accordingly. "Lean meat and fish are good choices," says Dorfman. More importantly, be sure to eat a piece of chocolate cake once in a while, too, to celebrate how far you've come.
82, from West Sussex
"I'd always kept fit through playing football, walking, lifting weights and managing my barber's shop. But I started running at nearly 60 and straight away decided I'd do a marathon. My best time was 4:05 when I was 62. I did several marathons a year including New York, Berlin and London.
"I run for an hour every day and my wife Jill makes sure I eat sensibly. I love running - you'd be crazy to do it at my age if you didn't love it - and it has kept me a trim 8st 7lb and in good health.
"I've now done 51 marathons. I walk some of the course these days, getting round in about eight hours. The day after the race I'm fit for nothing, but I soon bounce back. I'm certainly not planning to stop any time soon."