Peter, thanks very much for that study on the marathon runners from the
 researchers at SUNY-Buffalo. I remember a similar (if not the same) study
 summarized in Running Research News earlier this year or late last which
 said much the same thing.

My own experience as a runner bears out the general gist of what they are
 saying, as well as Bob Avery's comment in response to Douglas Schwartz that
 while too much exercise may be bad news, skimping on exercise can go too
 far in the other direction. While I agree with Douglas about overdoing
 exercise, as well as the study Peter quotes, from what I can see, many
 people into vegetarianism or at least natural hygiene, don't exercise at
 all, or at least so little they are not doing themselves any favors either.
 I think some of the exercise-is-bad rhetoric appeals to people because they
 don't like exercise in the first place, and without reading the studies
 very closely (that too little or no exercise is just as bad as doing too
 much) use it as an excuse to indulge themselves.

There is a general misconception that anyone who is a distance runner is out
 there killing themselves. Such people generally have not ever run
 themselves or know how easy it can be when you are in good shape. For me, a
 run of 4 miles is less tiring overall than a walk of the same distance
 because I am on the road for half the time, and what's more, it gives
 something back in the form of far superior aerobic conditioning.

I always have to laugh when I repeatedly hear natural hygienists tell me I
 am overdoing the running, yet when we look at -time spent- exercising
 rather than those mileage figures that seem to scare people, I am actually
 doing -less- exercise than some of the people pointing fingers at me. For
 example, when I was running 6/7 days/week totaling 35-40 miles a few years
 back, averaging maybe around 7:30/mile for most of those miles (an easy
 pace for me I can carry on a conversation at), that works out to an average
 of 45 minutes of exercise a day. That's actually pretty reasonable.

What I found was of more import was the -intensity- of the exercise and its
 affect on susceptibility to respiratory infections, flu, and so forth. (I
 can't comment on the effect of the 15% low-fat diet in the experiment,
 because I've never been able to stay on such a regimen very long without
 feeling deprived--20-25% maybe, but 15% is difficult to sustain for months
 at a time for me, although I've done it once or twice.)

You will notice in the SUNY-Buffalo study, these were marathon COMPETITORS
 doing 40 miles/week (like I used to do) but they were being tested after a
 "MAXIMAL EXERCISE TEST." Translation: In exercise-physiology terms, this
 refers to running yourself to complete exhaustion for the lab testers on a
 treadmill usually, where you are hooked up to wires and tubes while you are
 running, or if not on a treadmill, some environment where the researchers
 can hook you up to test equipment right afterwards to measure blood levels
 and so forth.

The conclusion people often jump to from experiments like these is that
 runners' immune levels are going to be this depressed after EVERY workout,
 when that is far from the case. Other tests show that reasonable (not,
 MAXIMAL) exercise ENHANCES immune function. The extreme stress of a maximal
 exercise test is on the same order as that of an all-out race competition
 situation, and most runners do not compete like that except once every week
 or two during a 3-month season in the spring, and 3 months in the fall. And
 that's for only the hard-core competitors at the elite level or in
 age-group competition.

The study cited in Running Research News (which as I say may or may not have
 been the same one as the SUNY study) which had much the same gist, took the
 results as an indication of the need to be very careful to rest and recover
 AFTER MAXIMAL ALL-OUT RACE COMPETITIONS. (Especially after marathon races
 which severely depress the immune system for several days or perhaps a week
 or so afterwards.) For shorter races (5Ks, etc.), the immune system usually
 bounces back fairly quickly, I believe within 24-48 hours or so.

When you are training to compete, what is going on physiologically is that
 you aim to build up your metabolic reserves with lengthy phases of easy
 modest training. But once you go into your hard training phase (2-3 hard
 workouts a week) which is known as the "peaking" process in training
 circles to bring yourself to your absolute peformance pinnacle, you start
 dipping into your reserves to pull off the hat trick

So what happens is that as you get closer to your competitive peak, you are
 depleting your metabolic reserves (this is not the same as nutritional
 reserves--more like Hans Selye's stress-reserve theory or something of that
 nature). Basically you are gaining a temporary state of "racing fitness" at
 the temporary expense of your stress reserves. The stories are legion of
 endurance athletes setting personal bests or world records and then getting
 injured soon after or succumbing to viruses or other illness. You are right
 on the razor's edge when at peak competitive fitness. Most garden-vareity
 runners out for their daily jog are nowhere even close to this level, however.

But it is true that HARD training can depress the immune system if you are
 doing it for more than just fitness reasons and training to compete. I
 started back up running around age 34/35 after a dozen years off following
 college, and worked my way up to about 40 miles week doing 2-3 hard
 workouts/week (less stressful than a race, but still a load on the body).
 I'd follow the hard/easy system (alternating hard and easy workouts to
 recover and progress in shape optimally), but I noticed I wasn't recovering
 as quickly as when I was younger. Adding animal foods to my diet turned
 this problem around rather quickly (I had been veggie for 18 years), but
 then I noticed as I began approaching age 40, like most runners inevitably
 face at this point, my recovery rate after exercise began slowing again. I
 also noticed that if I tried to continue the former level of training, I
 got sick more often, usually respiratory stuff, flu, etc.

So what I did, since I was still interested in competition at that point,
 was to go from every-day running to every-other-day running. I kept doing
 the same workouts as before, but just gave my body an extra day to recover,
 totaling about 20-25 miles/week of hard/easy training. The number of bouts
 of respiratory troubles/flu went back way down after doing this, so I
 thought I was pretty smart. But then I had a 4-mile race where I set a PR
 (personal best) off this kind of training, and thought I was superman and
 didn't rest enough following the race. I did a hard workout when I was
 still feeling tired from the race, and the next day came down with a killer
 respiratory problem of some kind--dunno exactly, but probably bronchitis or
 walking pneumonia which took weeks to get over. Similar thing happened some
 months later during an all-out 5K race in 90-degree weather and
 high-humidity here in Kansas which left me low for some weeks.

I came to the conclusion it was the maximal all-out races that were killing
 me, and decided that while I liked training and even occasional hard
 training which my body could seem to take and even enjoyed the brief
 challenge, it was no longer a good idea to keep putting myself on the
 razor's edge of competition. It has now been over a year since I've stopped
 racing, and zilch health problems since. (Knock on wood :-) )

But on the flip side: I also notice if I do not train regularly (more than
 just jogging), my blood-sugar-processing abilities--which I have an ongoing
 tussle with--deteriorate, as do my energy levels. I think I have found a
 happy medium finally.

Douglas, regarding caloric restriction in animals: I've seen these studies
 and they seem valid, and there is no reason to think the results wouldn't
 be somewhat the same in humans. I agree if one is interested in maximal
 life extension, then I say go for it, and more power to you if you want to
 be emaciated and eat a lot less, and you are happy and feel good doing it.

However, in the reports I have seen, there are indications the test animals
 are not very happy with the forced regimen. If one has the type of
 personality or discipline to adhere to one of these regimens without
 feeling deprived, then it wouldn't be a drawback, but the animals do seem
 to feel deprived, so there is a trade-off here: happiness. While I am
 somewhat emaciated-looking due to having a natural distance runner's build
 and I fit that aspect of the calorie-restricted picture, on the other hand
 my metabolism is very high, and so I eat quite a few calories. But I have
 also been on calorie-restricted diets (when I was eating almost 100% raw
 foods), and felt strung-out doing it. I wouldn't want to live my whole life
 that way, although I might be amenable to compressing all the suffering
 into a 14-day fast every few years, where I am also miserable but at least
 it's over with pretty quickly and you get deep, long-lasting results.

--Ward Nicholson <[log in to unmask]> Wichita, KS