A barrier to acceptance of strength training in golf has been the fear that increased muscle mass ("Bulking up") will have negative effects on flexibility and swing technique.

While this belief is common, it is based on a few misconceptions (1/5)

1. A well designed strength training can actually increase flexibility, particularly when exercises utilize a large range of motion. For example, Morton et al. (2011) found that resistance exercise had similar flexibility benefits as static stretching https://pubmed.ncbi.nlm.nih.gov/21969080/ 

2. Hypertrophy is a relatively slow process. Skilled golfers have ingrained their golf movement patterns over thousands of repetitions, they won't be meaningfully affected by a few lbs of muscle over the course of months. If anything, mass may be beneficial for some golfers

3. While hypertrophy contributes to strength/power, it's often not the primary goal for golf

Some of the most potent adaptations are neural, such asneural drive (which improves ability to recruit & fire motor units)

Image: Barry & Carson (2004):
https://pubmed.ncbi.nlm.nih.gov/15304540/ 

This means many golfers can have meaningful improvements in swing speed or distance without much increase in muscle mass due to improvements in these neuromuscular factors. Hypertrophy and other muscular factors can then further contribute beyond that

Note: initial research suggests golf swing kinematics may be altered by training. Though usually when they explicitly target specific aspects such as increased X-Factor or hip rotation. Also, current data has suggested no significant decline in accuracy/performance measures