Stress hormones. Read up on cortisol's effects. XCM - cross country marathon (MTB race). 2700mD+ - 2.7km of vertical gain. A reduction of inflammation is a general effect of anti-inflammatory drugs, which tend to make you feel better. There's a LOT more than that (i.e. say, all the things that fall under the umbrella of "runner's high"), but the TL:DR is that significant physical activity / energy expenditure, combined with a lack of proper rest & nutrition leads to long-term undesirable effects that can definitely be masked and/or disregarded.
Stress hormones. Read up on cortisol's effects. XCM - cross country marathon (MTB race). 2700mD+ - 2.7km of vertical gain. A reduction of inflammation is a general effect of anti-inflammatory drugs, which tend to make you feel better. There's a LOT more than that (i.e. say, all the things that fall under the umbrella of "runner's high"), but the TL:DR is that significant physical activity / energy expenditure, combined with a lack of proper rest & nutrition leads to long-term undesirable effects that can definitely be masked and/or disregarded.