You can absolutely exercise away a bad diet. The intensity and duration of exercise required is well above what most are willing to endure though.
Like, if you think jogging for 45 minutes is going to exercise away several cheeseburgers . . . you're going to be disappointed. If your idea of fun is holding around 85% max heart rate for five or six hours on a bike first thing in the morning, or doing an hour of heavy compound lifts approaching sets of 80% of your 1rm limit followed by an hour of sprinting hill intervals you're going to have better results.
With very heavy exercise, you actually hit a limit where you can't physically eat enough food to keep weight on. Like you get tired of chewing, and your stomach is so full it hurts so you stop.
I think this is why a lot of people struggle with weight gain after high school, I know I did.
Your metabolism slows down (then stays flat for like 40 years) but you were used to 2 hour practices daily for three seasons and had the heating habits to match. Plus if you are in college you have access to unlimited food.
Also, the garbage food people hiking the Appalachian trail eat (I live near it) always cracks me up. No way they can replace what they burned daily + Budget + Trail magic makes for some funny looking dinners.
Near as I can figure, metabolism slow-down as you age is a myth. It's ability to do work in the elderly that takes a hit.
I'm 44 now. I noticed that at around 40, my ability to exercise as intensely and for as long dropped in a measurable way. Based on my records, I require more recovery time than in the past after a hard effort, which limits my ability to go as hard. Specifically:
- I cannot physically move the kind of weight that I used to at 30 when lifting. The strength just isn't there any more.
- I can go the same distances at around the same times for cycling, but can't do it multiple days in a row like I used to.
I don't think that my metabolism has really slowed down at all. If I go for a 160km bike ride at a good pace, I am not able to eat and drink enough in two days to recover the weight that I lose. Like, I'll still go home, crash in front of the couch, and eat an extra large pizza on my own with no weight gain. My reduced recovery though, means that I can't do this multiple days back to back. In my youth I would exercise pretty hard six or seven days a week. Now, I need one day off a week, and one or two light days. I need to moderate what I eat on the light and off days because of the reduced load.
So, if you measure and track time/distance or weight/reps and what you eat after doing them, you'll find that these are still around where they used to be. But if you go by how hard it feels to do exercise then you'll find that you have to eat less because less and less exercise feels harder as you age.
What’s really interesting about your observation is that longevity scientists aren’t sure what exactly motor units are, but know that you lose them over time. And you lose more with disuse, and you can’t get them back. That’s why explosive movement is critical. Also, fast movement and reaction time is brain/nervous system training. Your brain learns to be slower and can permanently lose that fast reaction time without practice.
Everyone is slightly different and one person may notice age-related changes in their 30s, other not till their 60s, others not till their 80s. But the trouble with an n=1 type of analysis is that so often we confound other factors with age. What are those factors? Disuse, lack of sleep, stress/cortisol, nutrition, motivation…
In my 20s-30s with young children I had back trouble and felt much older than I do now. In my 50s (knock on wood) I haven’t had back trouble in years, I feel fitter than ever, my VO2 max is that of someone decades younger, etc.
I do think it’s true that you need to prioritize recovery/rest the older you get, and also do your best to avoid injury. Fasting, which had been in fashion for a while for longevity and weight loss, is now falling out of favor because especially men will see a lot of muscle loss or at least lack of growth without enough daily nutrition.
This amazing guy I AM LONGEVITY on YouTube has recently been taking Peter Attia to task for exclusively focusing on VO2 max as a measure of longevity. His point is always you have to do ALL THE THINGS. Anything that you stop doing you will lose the ability to do — not always, but often, permanently.
