Running isn’t the problem per se. Amanda Nyx, a former collegiate athlete and certified fitness instructor, says, “Many people don’t understand how to do it safely or at an appropriate level for themselves.” FYI, running for more than 17,000 days isn’t appropriate for most people (as you'll see from the fact that only one person has done it). Days off for recovery are important. If you want to set running goals, great. Just don’t aim to run every day for the foreseeable future.
Workouts that develop "long, lean" muscles
This trend gets a facelift every couple years, but the basic gist never changes: to get a "long, lean" body (or the latest marketing tool, the "dancer’s body"), you absolutely must lift super-light weights a million times.
Like running, these high-rep, low-weight workouts aren’t necessarily bad. Barre workouts, the Tracy Anderson Method, and even some cycling studios incorporate the tactic into their programs, but Jennifer McAmis, a fitness instructor and personal trainer, explains the problem is with the implication. If light weight-training means a long, toned body, heavy weight-training must mean a bulky body, right?