Both physical and intellectual improvement are related to two general processes: one is of a constructive kind, and the other is of a destructive kind. In some regards it can be a bit difficult to distinguish between those two, since for instance weight-lifting is ‘destructive’ in the sense that you tear some of your muscle fibers apart when you do your – especially heavier and more intense – exercises. But that is still a part of the constructive category, since you need it in order to rebuild your muscles fibres and make them grow (extend), in conjunction with a proper diet and a good overall quality of sleep. For the most part, all you need is some degree of common sense in order to grasp the main differences between what is constructive and what is destructive.
Destructive processes are, needless to say, for instance continous sleeping problems, an unhealthy diet, illness, and (longer) periods without training. Alcohol and partying is a topic that should be treated more separately and in more depth, in order to examine many of its different angles, but it may have some obvious indirect effects of the destructive sort, such as dehydration, lack of training the day after drinking or even for longer periods of time if it is a part of a continous pattern, and perhaps an increase of body fat due to that people tend to be less motivated to eat healthy when they party. It often does also undermine the ability to read and to study, and hence will have negative effects on your intellectual condition too.
Some of the destructive processes can be rather deleterious when you train natural and can only expect tiny improvements in regard to stregth and/or hypertrophy – even if you optimize, or even ‘maximize’ the total sum of constructive components. I can give some real life examples. For instance, in 2006 I visited the west coast of the US for a little bit less than a month, and I did not exercise at all, partied for at least five nights, and ate junk food for most of these days. Since I only ate two meals and walked a lot, I managed to decrease my body fat a little bit, though, but overall this was obviously not good for my physical development, rather the opposite.
During the spring of 2009, I traveled thorugh Japan – and visited South Korea and China as well – for a couple of months and I did not exercise at all. This was indeed a fantastic time of my life, of which I will neither forget nor regret, but from a physical perspective it was far from healthy. I remember when I came back to Stockholm and visited a gym just the day after my return, I could literally only manage to do three or maybe four strict chin-ups. It was not as much an increase of fat-weight as much as it was an obvious decrease of strength and overall level of fitness. At the end of the same year, I spent about three weeks in Australia, where I drank a lot of alcohol and ate a lot of junk food; actually to the extent that I gained a lot of fat-weight within that narrow timeframe.
These things are perhaps not very relevant to mention, since the chain of cause and effect is so obvious, but it is at least a little bit more conspicious that at the the time when I traveled to Australia – about four months after I got back from East Asia – I had regained the overall loss of physical strength of which I had lost earlier the same year. I experienced almost the same thing in 2011 in which I lost about 15 lbs of body weight – a combination of fat, water, and muscles – due to a quite seriously upset stomach, and consequently I lost some strength too. (It was in fact on the famous party island Bali in Indonesia, and as you can guess the three, almost four weeks, that I spent in Southeast Asia – I was in Malaysia and other parts of Indonesia too – were far from wellness-oriented.) In the summer of 2012 I only trained at a very insufficient home gym, in which the opportunity to exercise can only be seen as complemantary, not all-embracing; hence I experienced some increase of body fat and decrease of strength and muscularity after a period of about eight weeks.
The main point is that the constructive and destructive processes can be understood as a sum of both benefits and deficiencies, plus and minus. This individual sum is also time-related, so that although you might – depending on the depth level of your physical setbacks – reach the same level and eventually surpass that in due time, you will obviously lose more or less time to improve yourself, if seen in a larger timeframe. And time is a chief element that you definitely need in order to make physical, as well as intellectual, improvements throughout life.
Therefore one should constantly calculate and try to avoid or at least diminish destructive processes of which are far-reaching and time-consuming. If you are abroad for more extensive periods of time, then go quickly and find yourself a decent gym and good proteins, fruits and vegetables to eat on a everyday basis. Also bring a lot of good books, or buy new ones to read. The basic principles and praxis of body and brains are universal and thus they will work everywhere.
And lastly, when you are in your late twenties it is definitely questionable to party anything more than rarely, on special occasions, and likewise to backpack around the world for extensive periods of time. Instead one should have a suitable juncture in life, most likely a town or city, where not just to dwell but have the opportunity to evolve.