Physiology & Age

[skiguy]

In the Peak Zone

Dr. Wu....Bro your BioRhymums are in the midst of crossover!Overanalyzation is the end of all thinkin'..go for a HIKE..you'll feel better!

 

[Peakbagr]

Thanks for starting this thread. Fascinating replies. Thanks Mav for the science behind it all.

Alan

 

[Neil]

To relate all of this to aging...if you peruse the world or national records for any race distance which are stratified by age it becomes obvious that for any endeavour there is a peak age followed by a relentless, inevitable decline. Just recently a 95 year old man set a new world record in the 100 meters...for his age group. Something like 22 seconds.

Obviously something has to explain the decline. Decreased max heart rate? Loss of elasticity in the musculo-skeletal system? Decreased hormone production and loss of muscle development/repair capacity? Loss of vital capacity in the lungs?

It's probably all of the above.

One thing I know: My 16 year old son can do nothing physical for 2 weeks before a hike while I train regularly. Then we go for a big hike like the Dix Range maybe even running a few miles of trail. For the next three days I'm in pain, you know, the deep shredded muscle type. He's painfree the next day and plays floor hockey. His comment: "your old".

 

[forestgnome]

At age 41, my stamina has never been greater. I made it to West Bond for the first time last week. I felt completely fresh at the summit of Mt Bond, after hiking in from the Kancamagus. On past hikes I've been too sore at that point.

My biggest problem was my knees, untill I quit using the leg-extension machine at the gym. Now my knees are completely normal. General acheiness throughout my skeletal system, especially my feet, is what limits me. My cardiovascular and muscular systems could keep going.

 

[mavs00]

I agree Peakbagr, great stuff here……… just thought I’d add some more drivel. .

** I'll use and analgy we use in swim training, but I beleive it fits

We must remember that fitness levels (and the ability to perform) are much like a floating ball in a glass of water. The more water you put in the glass (i.e. training), the higher level your “fitness ball” will be at. But there is a limit (the top glass). When your young, your glass will be pretty dam big, but as you get older the glass will, sadly I’ll add , shrink. This is due to a many factors (Neil listed some good ones).

What are the implications of that? There are a few…. Foremost, you can manipulate your INDIVIDUAL "fitness ball" level to an extent. For example, the last few years I’ve been continually been “adding water” to my glass by training (be it running, hiking or other physical activities), so lets say I've currently got 16oz in my "performance cup”. My personal “endurance cup” (based on several factors like AGE, genetics, personal VO2 Max, etc) might only hold 24 oz at this point. If I worked harder (or smarter) I could possibly raise my level higher than 16 oz, but for now my 37 y/o glass can only hold a maximum of 24 oz.

When I was younger (upper 20’s to low 30’s), my glass probably had a maximum capacity of lets say 32 oz, and had I chosen to take advantage of it (by regular and consistant training), I could have done MUCH more endurance wise. But since I was a lazy lump , my glass probably only held 8oz (or less). Compared to then, the "16oz me" (now) can perform circles around the “8 oz me” (then), even though I’m considerably older. Likewise, I could go hiking (or running) with 20 y/o that might not work as hard at putting "water in" his cup that I do. He might only have a 16oz level (the same as mine), despite the fact that his potential cup is much bigger. We’d probably hike great together, because we’re drinking from a similar 16oz level, even if the the “size of the cup” we are using is different and we are different ages.

By the way, not only does the glass shrink with age, it’s starts to leak too ……. So, in 5 years, my cup (potential) might only hold 20 oz, but I’ll still be able to perform at my current 16oz level, I just will have to work harder at putting water in to maintain that level. More likely, I’ll stay on a similar training program and just let my current level sink to 13-14 oz, causing the inevitable slow down in performance.

Potential is different that current ability.

Neil, by the way, I'm in a similar boat, my 14 y/o son is currently drinking from a 16 oz cup/ His personal level is about 13-14 oz, so I can still whoop his butt . However, his is glass is growing by the day, in another year or two, my "little glass" will look like a friggin dixie cup next to his.

DOES ANY OF THAT MAKE SENSE?

 

[Artex]

DOES ANY OF THAT MAKE SENSE?

Perfectly. Great metaphor and well put. I was going to post something similiar, but had trouble coming up with how to say it effectively.

 

[frytz]

It's all relative, I'll be hitting 60 in two weeks, I can't hike as fast as I used to 20 years ago, but I have as much stamina, it's just used in a slower way. And the older I get, the more I appreciate my trips to the woods!

I will be 65 later this year and have gotten faster and stronger over the past 10 years. I will easily put in over 3000 miles hiking this year. But I think it's more attitude (mental) than muscle (physical). The body can do a lot more when it's willing!

Fred

 

[Neil]

So Mavs, what happens when our 24 oz. tumblers are mere thimbles? In the meantime I could plug my "leaky bucket" but then I wouldn't have as much fun!

One thing about the kids. Their cups seem to fill up spontaneously to capacity (those little rats).

Here's a tidbit:
Let's say you have an even 50-50 split of fast to slow twitch fibers. However, you work hard in the weight room and train for the 100 meter (foot) race. You're fast twitch fibers will hypertrophy preferentially and as far as volume goes you may train your way to a 70-30 ratio of fast to slow simply because the fast twitch fibers are now bigger than their slow counterparts.

One thing I've always wondered: If on most hikes most of the time we are using mostly our slow twitch fibers then the fast twitch would be dead weight. So every once in a while would it be good to push real hard for 90-120 seconds in order to profit from those fast twitch fibers and the glycogen that is locked up inside? Call it variable pace hiking.

 

[Maddy]

I woke up one morning 20+ yrs ago and realized I would never have another pain free day as long as I live. Some body part is always aching and if I manage to cure one another one starts up.
I don't dwell on it. At age 60 I completed a dogsled/ski exspedition in MN with Outward Bound. At age 30 I did not even have the guts to sign up. We travelled all day,every day, slept in minus 30-40 temps, set up camps nightly, picked thru 12-18"of ice for water, cared for sled dogs and each other, chopped and sawed wood, etc. We were all scared but we did it. I was the oldest. I've had lots of great experiences in the outdoors but none that compared to this.
Recently I went back to using the elleptical trainer and swimming at the Y. It seems that swimming at this age is great for the joints. No matter what I did I was really stiffening up but it's much better now.
I am much slower but can still do things that 90% of my peers at work would not even attempt and I'm the oldest of all of them.
I think one of the most difficult things has been accepting that I have slowed down some, I can't do high impact aerobics, but even with all the aches and pains of aging, I hope to continue to hike, bike, and train for many years to come. I keep myself in "big dog" puppies so there is no chance that sloth/ torpor and paralysis will set in.
To be honest, I am much tougher now than I ever was in my youth.
Someone said it well. Mental toughness is critical and helps immensely dealing with all the physiological changes of aging.

 

[Artex]

One thing I've always wondered: If on most hikes most of the time we are using mostly our slow twitch fibers then the fast twitch would be dead weight. So every once in a while would it be good to push real hard for 90-120 seconds in order to profit from those fast twitch fibers and the glycogen that is locked up inside? Call it variable pace hiking.

That sounds like a variation of the Fartlek training principle used by runners. Yes, it would be interesting to see how it would translate to hiking.

 

[Gris]

Pkbgr & Mavs nailed it. It's all about oxygen uptake. And, it's a proven fact that "interval" training is the way to maximize that!

 

[mavs00]

That sounds like a variation of the Fartlek training principle used by runners. Yes, it would be interesting to see how it would translate to hiking.

Sigh, at the risk of boring everyone to tears. This stuff is can get complicated.

The answer is NO. The "Slow" and "Fast" in Slow and Fast twitch muscle fibers do-not refer to the speed of motion and those fibers don't work like that. They are just tissue, or the engine used to generate and apply force (which translates to motion) Read-THIS- for good background info. In General, The twitch fibers basically refer to the speed and force generated by a particular muscle in order to make it work. Endurance activities are dominated by slow twitch, and the 2 fast twitch types are primary to speed events focusing on rapid applied force. The jury is out as to the ability to train fibers one way or the other, probably only limited amounts. What you’re born with is pretty much what you get. I don’t think they atrophy with non-use, like muscles do. Training to heavily at the anaerobic level tends to put significant strain on tissue, so the likelyhood of injury for older athelets goes up.

When you fartlek run, or alternate between fast and slow hiking (a form of interval type work), your actually talking about ENERGY SYSTEMS work. Here is an -DECENT GENERAL OVERVIEW- (although it more complicated there are several layers with in each system).

In fact, most of the training you do, depending on how you do it and how often, is specifically targeting one system or another. If you want to get better at short-power activities that focus on lots of rapid applied force (such as sprinting events), your training should focus on anaerobic power with lower amounts (but some) fitness based aerobic stuff.

In order to get better at endurance events, the reverse is true. If genetically you’re predisposed to endurance activities (all the other stuff I talked about), then you'll likely excel or have an easier time training those system thensat, some one that is not "blessed". It should be noted that there are SO MANY other different factors from stuff we talked about already to form, skill, nutritian, etc. that this isonly one factor, albeit a major one.

You can go on all day with this stuff . Come on, there must be other Kinesiology experts in here.

 

[Neil]

Pkbgr & Mavs nailed it. It's all about oxygen uptake. And, it's a proven fact that "interval" training is the way to maximize that!

Oxygen uptake, delivery and utilisation. Interval training gives the required stimulus and minimizes the damage caused thereby.

Just to elaborate on your preceding post Tim. The slow twitch fibers are recruited at ALL levels of contraction force. However as the contraction force (workload, not necessarily speed) increases from light to moderate a small percentage of fast twitch fibers begin firing. Then as one approaches maximal force of contraction one recruits more and more of their fast twitch (a & b) fibers which require a certain threshold of stimulus before they get off their arses and pay their way. The two groups each use different energy systems. Ie. slow=primarily aerobic, fast =primarily anearobic

The only way to get a training stimulus and improve the FT fibers' potential is to apply a heavy workload. Ie. speed training, hill running, fast uphill hiking .

Fast twitch fibers hypertrophy readily, hence the big sprinters. Slow twitch don't, hence the scrawny endurance athletes.
This of course is all greatly simplified and raises as many questions as it addresses.
Fascinating topic. We've drifted away from the physiology of aging, haven't we?

 

[JimB]

I'm no scientist but I do consider myself an endurance athelete and a few things I would add IMHO. As I age(I'm 49) I need to work year round on maintaining fitness. It is very difficult to start all over each spring. This will usually cause an overuse injury which causes a downward spiral of fitness. I think it's important to do lots of different activities to maintain fitness. Some might go to the gym but I prefer cycling, trail running, snowshoeing, nordic skiing, wood cutting, construction work,etc all done with an elevated effort and mixed in together as much as possible. At least once a week I try to do a 1-2 hour workout with some very fit people who will humor me and wait for me to catch up . This really helps my aerobic capacity and makes my endurance efforts more comfortable at a higher level. Another aspect for me is fuel management as I age. I need to stay very aware of my effort level as I exercise so that I don't use up my glycogen stores too soon and end up doing the bonk . It's hard to remember that your body just acts different as you grow gracefully older. Sometimes you get with the young guys and your mental ability can push the flesh into that place where you take a few days to recover or you run out of fuel and have to regroup in the middle of an outing. I've also noticed some neat heart rate things but I need to stop typing and get to work on oneof my many projects that are my real reasons for not being as fit as I would want to be .