For my aerobic exercises (treadmill, bicycle) I have some fairly simple metrics to measure what I’m accomplishing – simply the machines themselves tell me how far I’ve gone, how fast, and how many calories I’ve burned. It’s fairly easy to track this data and see changes, but also translate into real-world goals. Since starting the gym I’ve advanced from 5 miles in a session to 19 miles now, meaning, presumably, I could ride a real bike almost 4x as far. Now gym training is different than what I was doing at home because I have to pack my entire exercise into about a 2 hour window vs at home where I’d use machines, intermittently, during whole day. So I was doing about 40 miles/day at home (my maximum was about 70 miles) but that was spread over more time. The more intense workouts I do at gym are probably superior exercise because I manage to be closer to my peak output much of the time where I had a lazier pace at home. There has long been a debate in exercise/training circles over slow/long vs short/hard and most people believe a combination is actually best, i.e. doing some intense intervals in an overall easier and longer workout.
But what about strength training?
Today was the first day I’ve keep a journal (almost no one at gym does this, but I like the fact my particular gym has attitude that whatever you want to do is OK and there is no “right” way to workout, and, in fact, no one pays any attention to me (or anyone else)). So I used 11 machines, did three sets of 10 reps on each. I’ve used all the machines enough to now know where I can set the weight on each machine and finish each set, then all three sets, without getting too much muscle pain (lactic acid buildup) I have to quit (on a few machines I grimace with some level of pain still, but feeling pain is quite different than feeling fatigue (i.e. literally haven’t the strength to do one more rep)).
So between all the reps, 330 in all (takes about 25 minutes) I moved 14,000 lbs of weight (adjustable bricks of iron). For upper body only I did 6900 or a little less than half, but that’s partly because one lower body and one back machine it’s easy for me to go to much higher weights since my legs and core are stronger than my arms and shoulders.
But what does any of this mean?
I did a simple conversion (an online calculator), figuring on most machines I move the iron weights about a foot (some a bit more) and so, simply, I did 14,000 ft-lbs of work, which translates to 4.5 calories! (there is some confusion over “calorie” as the physics definition is not the weight burn (nutrition label) definition which is really kilocalories). Another conversion is, in total, I did about .4 horsepower (a very good athlete can do 1/3 or so HP continuously, like Tour de France riders).
IOW, while moving 14,000lbs of iron might sound like a big number it’s really not that much. That kinda disappointed me.
Then I thought about something else. When I walk a mile I’m moving 194lbs of weight (me) over 5280 feet, i.e. 1,024,320 ft-lbs, so 14,000 ft-lbs moving iron is only about 1.4% as much. Now on treadmill I burn (with moderately high intensity) about 150 calories/mile, so that translates to only 2 cals for moving the weight, even less than the mere physics unit-of-measure conversion (4.5cals).
I found some online sources that suggested a 30 minute strength training workout (whatever that means, even the body builder types rest between sets) burns about 115 calories (vs more like 250 for aerobic workout of same duration).
So all this suggests that strength training is basically irrelevant to weight loss which pretty much just translates from calorie burn (when I was meticulously keeping food diary, plus measuring calorie burn, I found my excess of burn vs eat, using the conversion factor of 3500 calories/lb-of-fat was basically correlated fairly closely (over months of my initial aggressive dieting) but at about 2X ratio (i.e. I had to run a 7000 calories deficit to lose one pound).
So it would seem strength training is pretty useless for weight control.
Now there is a counter-claim, that is there are two body measurements: 1) fat content (the usual obesity BMI thing where I was, originally, just barely in obese category, now just slightly in overweight category), and, 2) muscle mass ratio (much harder to measure). The claim is that higher muscle mass (versus high fat) increases baseline metabolic requirements, i.e. just sitting here at computer, but with more muscle mass I will be burning more calories. Perhaps, but I haven’t seen any authoritative sources claiming this (I have seen that body fat does only slightly increase baseline metabolism, i.e. a very thin person sitting and a fat person sitting use about the same calories, per hour).
Now if I calculate all this strength exercise I do sitting (now about 36,000 reps in about 46 days) and just look at the reps with weights (only 5lbs) I’ve done about 168,000 ft-lbs of work, or equivalent to about 12 gym days. But in some ways this is misleading – I’m not just moving the barbells, I’m also moving my arms. And while I have no idea what each arm weighs (10lbs, maybe) I do find I can do about 30 reps just moving arms vs 10 reps moving weights with about the same amount of fatigue and/or pain. BTW, I realized since I use two 5lbs barbells, but 168,000 ft-lbs should be double that, but still even though I do about 700 reps/day sitting (vs about 330 at gym) the much higher weight I move at the gym is much more significant (and many sources on strength training claim moving heavier weights fewer reps is better for building muscle, perhaps true, but doing reps (duration) is also useful for general fitness (vs. just body building).
So, simply put, I still can’t figure out a way to track my progress on this whole strength training thing.
But I have the “feeling” (i.e. intuitive, not emotional) that 15 days at gym and 45 days with sitting exercises have made a difference (my arms seem slightly more developed and my muscles, when I tense them, have more definition and are harder). In fact, I got this feeling I was craving protein (aerobic exercise does little damage to muscles and so little need of protein for repair). So I’ve started eating one small (4 oz) very lean steak per day. And I’ve now started doing a few more meals with fish. It feels like it’s making a difference.
In absolute terms I really can’t do any more weight on the machines than when I started, BUT, I can do more reps (and sets) and a bit more easily than I could when I started. So it’s seems I’ve made some progress.
Now what difference does any of this make, if it is actually having an effect? One of the sources I read about doing long walks is that core muscle strength is more important preparation than purely leg or purely cardiovascular conditioning. If nothing else I’d like my back to be a big stronger as I’d have to carry a moderately heavy pack, plus if upper body is stronger it would be easier to manage loads.
But all this hasn’t translated to much strength gain relative to simple exercises. If I’m lucky I can probably do about 5 pushups (vs while rowing crew I routinely did 50) and when it comes to pullups, until I rowed crew I couldn’t even do a single one (one fitness test as part of crew I managed to do 21) and right now I’m sure (haven’t tried, but one strength machine is almost equivalent to pullup) I couldn’t do a single one.
So I’d guess, from leg strength and CV I might be half of what I was doing crew at 20 and maybe 2/3rds of what I was doing triathlon at 40 but from upper body I’m still puny in comparison to either (crew definitely developed upper body, but also back; triathlon the swimming developed arms). Usually with age, men lose more upper body strength than lower body (after all, until we have trouble walking, just any amount of walking, even just standing up, still requires lower body strength).
I have no way to even begin to guess but I’d bet it will take at least a year of strength training to get my upper body to same level of fitness as lower body, but then, it’s taken about 3 years (I’ve plateau’ed for last two years of my five years of fitness kick) to reach my current lower body and CV.
But I’m fairly pleased. I was amazed that around 1/3 of men > 65 have some amount of disability when it comes to fitness and probably I’m in the upper 1/3 of all 70ish men, maybe even better than that. When I did triathlon (which is probably only 2% of people who can even do that) I was in the middle third, so perhaps at age 40 I might have been in top 5-10% of my age group so I’ll be fairly happy if I can work up to that again, even though I have no real clue what practical value it will have.