Lifting a weight that's too heavy for you is an error despite the part of the body you're working, however it can be really disastrous when performing shoulder workouts. The shoulders are complex and delicate joints that are not specifically simple to target, and if you do put them under excessive pressure before they're ready you can wind up with injuries that put you out of action for months.
Do not let the otter in the ottermode fool you. Building an ottermode body does not involve growing fur and gaining a belly. An ottermode body is characterized by...