The Physiological Society Benevolent (Financial Hardship) Fund

This not a blog... just a plug for the Physiological Society's hardship fund called the Benevolent Fund (or BenFund for short).  If you have an extreme financial crisis and work or study in a Physiology type of discipline, it might be worth checking it out.  I am now the Chair.
The link is here

Is Running Good For Your Health?

Here is the update on this blog:  
For a proper academic review of this subject see  Hunter and Eckstein 2009.

Exercise and osteoarthritis, two recent reports have been published with apparently conflicting conclusions:The medically orientated Nature Reviews in Rheumatology suggests there is (as I suggested in the previous blog optimal joint usage for healthy cartilage), and a sports medicine journal article from Dr Williams suggests that long distance running decreases risk of osteoarthritis.  

Naturally, from the Twittersphere, those people who love running feel their pursuit has been justified.  those people who commercial promote exercise will use it as propaganda.  I find it sad that on this issue, just like so many, people pick the evidence that suits their believes rather than balancing evidence.

Now lets start with a reminder.  Osteoarthritis is a condition of painful joints, which involves the whole joint, but one of its hall marks is the loss of cartilage.  Cartilage lines the hip and knee joints.  The cells that make it (chondrocytes) actually sit within the the cartilage of the joint.  They respond to the loads placed upon the joint by producing cartilage... within reason.  If you don't use a knee and hip joint at all, you would expect the muscles to waste away, the bones to become thin and brittle, and the cartilage become thin also.  I think we can probably all agree on this.  However, cartilage is a living tissue.  It is not shoe leather.  Part of the confusion is caused because cartilage has no blood vessels so it does not bleed, and it has no nerve fibers running out of it so you don't feel pain from the cartilage itself.  But it still needs to be loved!  We know for absolute certainty that excessive weight (high BMI) promotes you getting osteoarthritis, even the Dr William's paper shows this.

There is clearly debate as to how much usage is ideal.  The sporty paper could be used to support the argument that "it's the more the merrier", but there are huge confounding variables.  The author did what he could, but it is difficult!!! The analysis was not able to exclude two possibilities (1) That slimmer people (with lower BMI) may run more and (2) That people could start to run less when they get painful joints. If you believe that either (1) or (2) could be true they presumably you will come to the conclusion that this new paper does not really answer the key question of how much usage is ideal.

So the other paper, the Nature review?  Well it is just a few line summary of a very thorough paper in the "Osteoarthritis and Cartilage" journal.  But This is what is reported.  The LEAST active elderly people loose cartilage, but so do the MOST active!!!  Activity is assessed with a PASE survey, and yes age and BMI is taken into account.  Also, the study tracks people and so ceasing activity due to joint pain is less of a factor.  Now bare in mind this is activity assessed by PASE not running marathons!  PASE asks a number of activity questions, see Table 1. They then considered the top 15% and bottom 15% activity rates and compared against the middling people.
...BUT and here is the elephant in the room.  The health crises we have at the moment is due to obesity and lack of exercise of people, not over exercise, so whilst I would suggest that the jury is out on how much exercise is good for your joints.... for the rest of you LOTS of exercise is clearly a great thing.  ...and for me too, but I am lazy :-/

 So the conclusion:  Everything in moderation? 

Table 1: PASE Activities, Performances and Weight Scores
PASE stands for: Physical Activity Scale for the Elderly

Activity	Answer	points
Walking and bicycling	Hour/day	20
Light SRA	Hour/day	21
Moderate SRA	Hour/day	23
Heavy SRA	Hour/day	23
Muscle strength/endurance	Hour/day	30
Paid/unpaid work	Yes/no	21
Light housework	Yes/no	25
Heavy housework	Yes/no	25
Home repairs	Yes/no	30
Lawn work	Yes/no	36
Gardening	Yes/no	20
Caring for others	Yes/no	35

 

Exercise and Obesity

Now I have to say I think the BBC "People men made us thin" series has been great, and in many ways music to my ears.  

The dogma are:

(1) Eating too much makes you fat.

(2) Exercise makes you thin.

(3) Genes

Do diets make you thin?

(1) They have gone some way to debunk this in the program.  Of course they have taken an extreme attitude.  If you don't eat, you will loose weight, but the psychology of dieting is more complex.  The study designs are difficult too.  So they studies showing diets don't work will usually say "here's a dieter 2 years later and they have put on 10lbs/5Kg, but here is a non-dieter and this person put on zero weight: ergo, dieting doesn't work".

There is a fundamental flaw in this argument though.  The people who diet typically have weight control issues and were always going to put on more weight than people who have never had a problem and never diet!!

So my bottom line would be that dieting is in no way all that it is cracked up to be, but if you are over-weight it is better to try and reduce your calorie intake than to just give up!!

(2) Does exercise make you thin

Again the program takes an extremist view of this issue.  I it is true that exercise is a really slow and relatively ineffective way of loosing weight  ...but it depends on the exercise, and whether it was the only lifestyle change you made.  Really this is a life-style thing.  To simply drive to the gym 3 times a week and burn off a few hundred calories is not going to make a significant contribution to a serious weight problem.  Those few hundred calories could easily be swallowed up just by one post exercise trip to Starbucks.  If you control calories and do more exercise, the exercise will prolong your life and keep you healthier, but really its the calorie-control bit that will knock off the pounds. Turn down that free chocolate bar at the checkout and you have just saved the equivalent of about a two mile run!  

(3) Genes

Your genes profoundly affect your weight.  This is mostly by changing the appetite control systems in your body.  Potentially there are many drugs which could change this, but it's not a great idea just yet, because these drugs tend to do too much other stuff.  ..i.e., "side effects".

All this lot is just the same for your pets too.  It's really important to give a dog a great walk or two every day... but weighing their dinners are the secret of weight control!!

Exercise and Osteoarthritis

 

OK... Now we have a bit of a problem on the osteoarthritis and exercise front.

.........because exercise is good for joints, lack of exercise leads to obesity and is terrible for joints!

.....but its long been believed that traumatic injury (knocks and bangs!) leads to, or exacerbates osteoarthritis, but studies now show that, in rats a least, intensive exercise also contributes to osteoarthritis.  To be honest, a search of the major osteoarthritis journal Osteoarthritis and Cartilage will tell you that there are several similar studies, but this one attracted my attention; Carlos E.S. Franciozi et al 2013.  The tricky thing is that this implies that there is an optimal amount of exercise for you joint health.  How much is that?  Sadly, we just don't know :-(

It seems sensible to conclude that the amount required to stay fit, but no more!  That is bad news for MOST people, because most people either don't exercise at all or exercise massively!  ...me? Well I dog walk.  I don't think anyone has implicate that as hazardous for your joints yet!