correlation between strength & flexibility
Weight training is the best modality for muscle growth, but lifting weights shortens muscles and makes us less flexible. Oddly enough, flexibility and strength work together. “With extremely poor flexibility, strength is not gained as quickly compared with individuals with normal flexibility.” Research has shown that if an opposing muscle group has limited flexibility, like tight hamstrings, it also hinders strength and size, of the quads.
If you have trouble gaining muscle mass, and are eating sufficient nutrients, calories and protein, are changing-up and progressing your workouts, are sleeping 7-8 hours a day, a lack of flexibility might be what’s killing your gains.
If you have limited flexibility, make sure to gently stretch at the end of every workout for 5-10 minutes, holding each stretch for 30 to 60 seconds. You don’t need to as flexible as Gumby to get stronger, so don’t stress out if you can’t do a backbend.
Source: Hatfield PhD., Frederic. Fitness: the Complete Guide. Carpinteria: International Sports Sciences Association. 9th ed., 2018. Print. Pgs. 311-312.