Well at least cycling and treadmill running are very well suited to multitasking. With enough motivation it is possible to squeeze in 4+ hours per day of cycling that you would be spending stationary while on your job or at home doing emails, at least some calls, reading, research, TV-shows&#x2F;documentaries&#x2F;online courses&#x2F;hacker news. Throw in the &quot;normal&quot; 2 hours of exercise before or after work and voilá!<p>It does take one 4-5 years to build up to that even from non-sedentary active lifestyles, otherwise maintaining energy for everything else will be impossible.<p>And my (completely speculatory) hypothesis is that amateur sports (or some pro-sports) or serious goal-oriented strength&#x2F;physique training will offer benefits down the line, as long as you quit &quot;heavy&quot; exercise after a reasonable amount of time <i>and</i> maintain a moderate amount of exercise for the rest of your life.<p>After all, Tour de France riders of the past century outlive us by many years, despite most allegedly having been on quite a comprehensive cocktail of anabolic steroids, erythropoietin stimulating drugs, amphetamines, etc..