Training & Nutrition - Why isn't biking considered a "load bearing" activity?

I have read that in order to ward off osteoperosis (sp?), deterioration of the bones as age progresses, one needs to be involved in a "load bearing" activity such as power walking or running. I have also read that cycling is not considered a load bearing activity, and I don't understand why. When you're cranking along, you're putting a load on your feet, ankles, knees and hips, expecially when you're up on the pegs on hills. Anybody know about this? I used to be a long distance runner, but my knees went out. This is why I took up biking, which is now my only sport.

I'd also like to ask whether the type of riding being done has any effect on the "load bearing status" of cycling. Is a flat coastal cruise considered different to a 1,000 metre mountain climb?

I think the reason cycling wouldn't be considered loadbearing is because your weight ie the load is supported on the bike .I would think loading the bike or going uphill would make it loadbearing to some extent.With running as you noted you have to watch for repetitive stress to the joints.Weighttraining is loadbearing and can be adapted to a fullbody routine but but you have to watch going to heavy or using improper form or you can damage the joints as well.

hm... usually when i hear this discussed it is in the positive: that cycling is good b/c it is NOT a load-bearing excercise like running.

in reference to osteoporosis, i don't know really... i think cycling does a great job of keeping the joints and legs and all fit and strong as well as general fitness. but opsteoperosis is pretty much in the back and spine i think and since your spine is only half-active keeping you sitting on the bike (beacuse the seat supports much of your weight), i could see that it might not provide a lot of work for the spine and back. although there is some work involved in the lower back depending on the position on the bike (on an agressive road bike with forward stance either your lower back provides the support or else you put all your weight on your hands and they go numb). and i'm pretty sure that standing out of the saddle and climbing IS load-bearing, but then most people don't spend a great deal of time out of the saddle.

in my case i also do lots of other sports and training - hiking, skiing, running, rock climbing, weight lifting, but cycling is my primary sport.

ok, here i'm only speculating, but my guess is that the amount of "load-bearing" exercise needed to ward off osteoporsis is not so great - maybe an hour or so a week - so with the little you get from out-of-the-saddle plus maybe one day a week running or walking i would think you should be covered... (i.e. as long as you're not a couch potato sitting at desk, behind the wheel, lying in bed...) but i guess a sports or health professional would know better than i

so why are you asking?

i think it IS a good idea to do more than one sport - cycling is great but there are some muscles and stuff it doesn't work out - supplement with some swimming, running, hiking, plus some weight lifting...

i.e. Cross-Train ever so often for maximum health benefits!

Unless you are standing for all of your riding, the primary load is on your butt. Some on your hands and some on your feet, but mostly on your butt. Not too much different than sitting on a couch. So isn't load bearing, such as walking.

but opsteoperosis is pretty much in the back and spine

Nope. Osteoporosis can be and is a general lack of density in bones in the body. If it affects one bone it is affecting them all.

In fact, they test for osteo by using a special x-ray of the wrist/arm.

Certain drugs such as Fosamax are very effective in treating and reversing osteoporosis.

I lift fairly heavy weights (at least for me) and walk as osteo prevention. Over the years, weight lifting will strengthen joints, tendons and other supporting structures.

Do some internet research, and you will find that bicycling does help just a little with osteoporosis, but not much.

I've heard jogging/running recommended to stave off osteoporosis. The reason given is that the "pounding" from footfalls introduces the bone stress that causes the rebuilding response. The same reason you might have given up running and started cycling! ;)

Where did you hear this from or read this at? As far as cycling not being a impact sport, such as running, no it is not, (until you crash anyway). But there is little or no impact on your body.

But it is load bearing in the sense that you are stressing and putting a load on a lot of your muscles and bones when you ride. Especially when you ride up hill. Most of the load bearing is in your legs and lower back from pedaling. As well as your arms and shoulders from supporting your upper body and conrtolling your bike.

The more you weigh the more you put a load on your bonse and muscles when you ride up hill.

So I'd say no it is not high impact but yes it is load bearing.

I'd like to know where you heard or read this at.

I've heard it is not load bearing either, in the sense of helping to maintain/increase bone density. The same goes for swimming. In both exercises the body weight is being supported by something other than your bones, (except your sit bones!).

I've also heard that in events such as the TDF, where the cyclists are in the saddle for prolonged periods of time over a long chronological period, they actually lose bone density, similar to the astronauts after a period of wieghtlessness. I don't remember where I read that though, so I can't substantiate it.

If out of the saddle, up on the pegs riding is considered somewhat load bearing, maybe we should all be like the guy mentioned several years ago in Bicycling Magazine. Can't remember his name, but he was a road racer and did much of his training with the seat removed from the bike. This could be a great training technique until you forget about the missing seat and try to sit down. Ouch! :cool:

but he was a road racer and did much of his training with the seat removed from the bike. This could be a great training technique until you forget about the missing seat and try to sit down. Ouch!

i had a knee injury about 4 years ago and figured out that cycling while standing was less bad for it (it was the acute bend that was bad) so i rode a lot for about 2 months standing about 90% of the time. i tell you, doing fast group rides (mostly off-road) without sitting is a WORKOUT!

There is some evidence to show that vibration can help slow down bone loss, and bikes provide plenty of vibration (if you avoid sus bikes).

You can do load-bearing exercise on a bike - if you use a high gear - but then you'll destroy your knees.

Weight-lifting is the most appropriate load-bearing activity - using heavy weights and low repetition will do more work and is less likely to cause damage than running.

When you get a flat tyre you'll get plenty of walking in.

From what I remember from my aerobics certification, load bearing exercise is exercise that places the most load (or weight, or pressure- whatever word works for you) on the bones. It's the impact the feet make on the ground when the body works against gravity, which creates muscle stress. This muscle stress in turn builds up the bone (or bone density). As we all know, lack of bone density leads to osteoperosis problems later in life. So a solution to prevent osteoperosis is to work with exercises that place a greater stress on the bones. So, although cycling places some stress on the bones, it is not as much stress as jogging, where you have the full body weight working against gravity and placing pressure on the bones- a result of the impact of the feet hitting the ground. It would also follow that there will be some exercises that are more beneficial to preventing bone loss than others- ie weight training and jogging or walking over cycling and rowing. Not to say there's absolutely no load bearing in cycling- there is some when you come out of the saddle for some breakaways or surges, and pedaling does place some minimal stress on the bones, but you get far more load with running. This has less to do with anaerobic or aerobic cardiovascular exercise and mostly to do with stress and load on the bones.

If you're concerned about osteoperosis, you may want to consider adding weight lifting to your fitness routine, and also consider taking a calcium supplement. Plus, you'll want to see your doctor, of course and have a bone density test.

I had a bone density test done on accident- I was participating in a research study at my university about bodyfat percentage, and part of the study had to do with bone density, so I got to find out that I had lots of bone density.... so I guess I can tell everyone I'm not fat- I'm big-boned! :D

Koffee

It should be in a relative term : Cycling ain't as 'load bearing' as running to produce high bone density.

However, squash and weight-lifting is more recommended to build bone mass. Not sure why? Check this out : http://www.pponline.co.uk/encyc/0399.htm

Good site oxologic, thanks!

Right, it is. It does reinforce the statements I made about gravity, stress on the bones, and impact. I could never do squash myself... for all that jumping around and ducking and bobbing, I would be dead before an hour passed on the court!

Koffee

to adequately understand "load-bearing activity" you need to consider the ultimate: heavy weightlifting. nothing staves off the ravages of age-related bone loss better than heavy weightlifting. that means lifting enough weight that you can only do 12 repetitions (reps) before exhaustion.

a typical weightlifter, such as myself, can do 12 reps in about 20 seconds. compare that to a typical bicycle ride, which ranges from 30 minutes to three hours. however hard you hammer up a hill, you're not going to exhaust yourself in 20 seconds.

for optimal fitness, i personally think you need both highly aerobic (cycling, swimming, running, etc.) and load-bearing (weight lifting) activities. i have found that the combination of the two can be excellent for your health:

1) the cycling will give you unlimited cariovascular capacity. (by the way, if you think that weightlifting is not a cardiovascular sport, you haven't tried doing it seriously!)

2) weightlifting will give you massive strength for short burst up hills or sprinting for the finish line.

3) i have found that regular heavy weightlifting has virtually eliminated all the little aches and pains that most people endure when cycling.

Interesting.

Years ago, a 72 year old woman runner challenged the current Mr. America (weightlifter) to engage her in a treadmill competition. She ran him into the ground at Dr. Ken Cooper's Aerobics Clinic in Texas.

"Load Bearing" is defined as you having to support your body weight. During running, your energy is going towards moving a certain mass (your entire body) along a path. During this time, you are overcoming gravity and friction forces that are opposing forward movement.

In cycling, you still have to overcome those resistive forces, but the bike is supporting the mass (your body weight - even though mass and weight aren't the same thing, I'll use them together for simplicity). All you have to do on the bike, is produce enough energy to overcome those resistive forces.

The actual load bering part comes when your bones and muscles have to "bear the load" that is placed on them. While running, each step that you take exerts a force of about 5 times the force of gravity upward and into your body. This is what builds bone strength and increases bone mineralization to prevent osteoporosis. During cycling, you're not experiencing a stimulus to your skeletal system strong enough to elicit regeneration of bone since there is no breakdown taking place. In cycling, you're using your muscles of mostly the lower body to move yourself along, while in running, you are doing the same thing, except also putting a stress on your bones with each step. It's this stress that makes running a load bearing activity and cycling a non load bearing activity.

geehan ... too bad mr. america didn't also bicycle! that'll teach 'im, the big oaf.

Hey Bandit, I'm not sure what kind of cycling you're doing, but I can come up with multiple exercises that can exhaust you in 20 seconds.

I agree with your statement that weight lifting is an excellent way to increase your BMD, etc.

There is one area of your post that I don't agree with though. You said:

to adequately understand "load-bearing activity" you need to consider the ultimate: heavy weightlifting. nothing staves off the ravages of age-related bone loss better than heavy weightlifting. that means lifting enough weight that you can only do 12 repetitions (reps) before exhaustion[I][U]

You can still reap the benefits of increasing your BMD (bone mineral density) by doing any type of weight training, from something as simply as a wall squat to explosive strength training such as olympic lifting with multiple sets of 2 reps for example. It's not only doing reps until exhaustion that helps your body.[I][U]

point taken.

all i know is this: i was exclusively into aerobics (cycling, running, swimming, etc.) for many, many years (i'm 45). never saw the need for weights. it's only been in the last five years that i've taken up weight training seriously, and i have to tell you that, combining weights with cycling, i've never felt better in my life. my doc even asked me: "what have you been doing? whatever it is, keep it up!"

i wanted to share that discovery.

Definitely agree with you there, dude. It's a great way to get stronger and bring most people to the next level in their development.

More info on osteoporous. This comes from the AMA brochure "Understanding Osteoporous.

Peak bone mass is reached in a person's 20's and bone loss over the next 20 years should be slight unless the following occur: diet low in calcium and vitamin D, an inactive life style, low estrogen or testosterone levels or a disease or medication that causes bone loss.

Bone loss in women usually begins in their 40's but is most rapid during the first few years after menopause.

Most men do not begin to lose bone mass until their 50's and their rate of bone loss is not as rapid as women's. However, men can experience substantial bone loss beginning in their 70's with the number of fractures in men approaching that of women.

Calcium is the main building block of bone and is essential for bone health. However, it will not protect you if there is estrogen deficiency, physical inactivity, alcohol abuse, smoking, various medical disorders or medications known to cause bone loss.

Bones are similiar to muscles in that they respond to exercise by becoming stronger and denser. Just like muscle, bones loose density by not being used.

Weight bearing and resistance exercise are recommended best for bone health. Exercises that have your feet and legs bearing your weight are recommended. Weight lifting has been shown to benefit bone health at all ages. Cycling is not considered weight bearing.

Also, the National Osteoporosis Foundation recommends a Dexascan of the hip and spine as the most reliable test. Heel and wrist scans can be calibrated incorrectly.

Kathi

I took an exercise physiology course last summer from a guy that has done a lot of research on professional cyclists. He was saying that some of the 20 something guys he tested had BMDs that you would expect to see in a 40-50 year old women in the first stages of osetoperosis

I wonder if in looking at the bone mass of cyclists, and seeing that they have less than others, researches are ignoring some important factors.
People with less bone mass weight less, so are more effective riders in terms of power/weight.
People with less bone mass are more prone to injury in contact sports, so tend to avoid them, and are drawn to less injury-producing activities such as cycling.

In general, cycling is an activity which is attractive to people with slight bodies and lightly-built skeletons.

Originally posted by MichaelW
I wonder if in looking at the bone mass of cyclists, and seeing that they have less than others, researches are ignoring some important factors.
People with less bone mass weight less, so are more effective riders in terms of power/weight.
People with less bone mass are more prone to injury in contact sports, so tend to avoid them, and are drawn to less injury-producing activities such as cycling.

In general, cycling is an activity which is attractive to people with slight bodies and lightly-built skeletons.

You may be right about cyclists tending to avoide contact sports, but there's a trade off for the reduction of injury. Later in life they will suffer the consequenses of doing one single non-weight bearing sport. Lance, for example, is a perfect example of how cyclists can maintain their BMD and still be highly competitive. He won the dirty duathlon not long after the Tour, got passed on the bike leg, but outran everyone on the course. If he were to stick to only cycling, he would have been taken to school on that day, but his cross training helps him maintain that important bone mass that is critical in people of all ages.

Don't forget the role that genetics plays in this. If its in your genes you are already predisposed to have it.
Also, any testing device except for the Dexascan (of hip and spine) is not 100% reliable. Wrist and ankle scans are only as good as the calibration on them.
After I broke my wrist 5 years ago I had read that women who had a non traumatic fracture of wrist,ankle or spine should be tested for osteoporosis. My doctors felt this was unnecessary but one did agree to test my ankle. The results said that I was almost off the scale on the positive side. For about six months I was elated but I had this nagging thought about my mother who broke her wrist about the same age I did (she has severe osteoporosis) but she was an alcoholic. The doctors said it was the alcoholism that caused her disease. When I read about the problems with calibratiing the heel scan I got a dexascan. Surprise, surprise, I had enough bone loss in my spine to go on Actonel.
I had been exercising since my late 30's mostly walking, aerobics, weight lifting, cycling. I didn't start mostly cycling until the last 3 or 4 years.
I know the alcoholism caused my mother to have the severe debilitation that she has now but its scary that at 53 I was already experiencing bone loss, especially when I thought I was doing everything to avoid it.
My grandmother also had osteoporosis and I believe that no matter what it's in my genes and I can't avoid it.
The good news is that had I not been so active my bone loss would have probably been worse.
I am also very small boned and have a low weight. But the weight is natural to me and the small bones are probably also genetic.
So anyone who is really concerned about this should get the recommended doses of calcium, exercise, including weight lifting, stay informed and get tested if they have any doubts.

Who says cycling isn't a contact sport? Two years ago, I crashed at 35 mph and bounced along the road like a rubber ball. Bruised and sore, but no broken bones at age 62. (I drink alot of milk) :D

I don't know if mountain bikers would be included with the road bikers. I've hugged alot of trees, endos, crashed etc. so i would think mountain biking is more of a contact sport and maybe even more load bearing (bunny hops).

:o test

I was right. Mountain biking does confer bone protection (if you don't break it that is.)





Bone 2002 Jan;30(1):281-6 (ISSN: 8756-3282)
Warner SE; Shaw JM; Dalsky GP
Department of Exercise and Sport Science, University of Utah, Salt Lake City, UT 84112-0920, USA. s.warner@m.cc.utah.edu.
The purpose of this study was to compare the bone mineral density (BMD) of two types of trained male cyclists (n = 30) with recreationally active men (n = 15), aged 20-40 years. Sixteen of the cyclists regularly trained for, and competed in, cross-country mountain bike races. The other 14 cyclists trained and raced on the road. The cyclists had trained an average of 11 3 hours per week for 8 4 years. Fifteen recreationally active men volunteered as controls. Dual-energy X-ray absorptiometry (DXA) was used to assess BMD of the proximal femur, lumbar spine, and total body. Anthropometric, muscle strength and power, aerobic fitness, and sex hormone data assessments were conducted on all participants. Mountain cyclists were younger and weighed less than road cyclists and controls. BMD at all sites was comparable among the three groups (p > 0.05). When adjusted for body weight and controlled for age, BMD was significantly higher at all sites in the mountain cyclists compared with the road cyclists and controls. Some anthropometric, physical fitness, and sex steroid variables were predictive of BMD, but of these variables, only total body weight, total body fat, and aerobic fitness were different between the groups. In conclusion, endurance road cycling does not appear to be any more beneficial to bone health than recreational activity in apparently healthy men of normal bone mass. Higher BMD in the mountain cyclists suggests that mountain cycling may provide an osteogenic stimulus that is not inherent to road cycling.

Interesting. I wonder what mechanisms can be isolated that support this "load bearing" exercise promotes bone density theory.

Would this mean that walkers and joggers will maintain denser leg and hips bones, but if you "walk" on your hands and knees you promote denser shoulder and arm bones.??

Do weight lifters who askew "standing" exercises and walking, have developed shoulder/clavicle and arm-bone density but "poor" leg and hip structures.

Inquiring minds want to know......how does a given "muscle" load transfer indicators to metabolic processes that promote bone density?

Cranium

I'm not sure what the question is and so I may be answering your question with the wrong answer.

Epidemiological data supporting load bearing exercise as protective of bone density is not in question. The data is overwhelming. Clinical trials that were prospective (best kind of data) and carried out over many years is also not in question.

I believe your question is the exact physiolgic/biochemical mechanism of this increased bone densities and could you affect local bone densities depending on the manner in which the load bearing excercise was preformed.

The physiologic mechanism is so complex it would take weeks worth of lectures to cover it. Basically, bone is built when the balance of the cells that build bone (osteoblasts) vs cells that tear down and remodel bone (osteoclasts) favor the osteoblasts.

Bone is a dynamic tissue so it is always in flux and is in the constant state of repair and disrepair.

It involves an interplay of so many hormones and chemicals(parathyroid hormone, growth hormone, calcium, phospherous, magnesium, estrogen and testosterone status, kidney humeral factors etc.)

Because bone remodelling is such a systemic (rather than local phenomenom), these load bearing exercises do not really increase the bone densities of the joint bearing most of the load.

That might answer your first question about running on your hands. Makes absolute mechanical sense, (muscles develop ) but in clincial studies the bone densities in a runner's hip, leg, spine, arm , and skull all increase with greater impact bearing activity. It's equivalent to trying to spot reduce your abdomen/gut withuout losing wieght every where else.


The cascade triggered by the impact sports,( ie:running triggers release of growth hormone, parathyroid hormone, that affects Vitamin D uptake in kidneys and calcium uptake in guts etc. etc. etc. after a zillionn pathways it instructs osteoblasts to grab the calcium out of the blood and place in back in bone and also place collagenous tissue in the bone matrix etc.) is........ unknown!


The answer will most likely be provided by the zero gravity research (preformed in the space shuttle and ongoing in space station). (Remember, o gravity is a trigger for lower bone densities, and yes, these astronauts have osteoperosis or lower bone densities on return to earth.)

Nice explanation.

My son takes Fosamax for what was severe osteo, but that has improved greatly to what is now called osteopenia.

The Fosamax works as you suggested by altering the bone building/tearing down ratio.

It has been a wonder for him.

(Incidentally, he was always involved in load-bearing activities - particularly jumping and walking, so we do not know the exact cause of the osteo.)

Men with low bone densities may have underlying thyroid problems, parathyroid adenomas, or hypogonadism (low testosterone from physical trauma to testicles etc.)

Did his doc check these levels out?


Also certain medications can cause it. A popular seizure medicine called dilantin (phenytoin) can do this. Malabsorption syndromes (that prevent intestinal absorption of fat soluble vitamins like VitD) can cause osteoperosis and these include celiac disease, crohn's disease etc.

It is uncommon for men to have osteoperosis (unless they drink or smoke heavily) such that most doctors look for underlying causes.

Yes, the docs have checked things out. He is under the care of a competent endocrinologist.

Originally posted by trmcgeehan
Years ago, a 72 year old woman runner challenged the current Mr. America (weightlifter) to engage her in a treadmill competition. She ran him into the ground at Dr. Ken Cooper's Aerobics Clinic in Texas.

Yeah...so? That would be obvious as he is a strength athlete and not endurance...stick her under a leg press machine and he would smoke her ;)

From: CBHUNGRY's previous posting,
>Because bone remodelling is such a systemic ......... load bearing exercises do >not really increase the bone densities of the joint bearing most of the load.
>
>..........It's equivalent to trying to spot reduce your abdomen/gut withuout >losing wieght every where else.

An absolutely brilliant analogy! Thank you for the illumination of this subject.

In a previous life I had written a text, on the role of milk fortification in the American diet and the possible repercussions or consequences of fortified milk in the diet of the geriatric community. I haven't revisited the subject, but I'm quite sure that as you previously stated, that many "mechanisms" remain unclear......

Thanks again.