I believe there use to be many people that said golfers should not lift heavy weights. And I assumed this was because they were worried about bulking up and losing “touch” or feel. I imagine this could be a problem if someone spends years and years increasing strength and size (imagine like a bodybuilder). However, this is unlikely for almost everyone, so not a particularly good argument against lifting weights!
Over the years many professional golfers have been into weight training. Most notably with Tiger Woods, then maybe Rory McIlroy and more recently, Bryson DeChambeau. However, their training might look very different even though they all 'lift weights'.
I think it was the trend in the naughties (2000's) to train with higher reps and train for joint/core stability with various training aids. And I think it was then the same for those that were training for golf. I could be wrong, but this was the impression I got.
Not to say that this can't be useful (i.e. high reps and core stability) but when looking at the needs of golf and the golf swing, high reps and low level core stability dont spring to mind. When looking at the golf swing, particularly with the driver, its about using a good range of motion to create force quickly.
Force is essentially strength and exerting that quickly would be power. To develop these qualities, firstly, we need to practise exerting force. This is best done through lifting heavy weights (about 85% or more of your 1-rep max). And to move quickly it can be practising quick movements (unloaded or with light weight). And anything in between with an intent to move as quick as you can.
However, this is not to say you should immediately go out and lift something really heavy and/or perform explosive exercises either! As usual, there is a lot this depends upon. For example, it is a good idea to work up to this. See example below…
Week 1-4 = 10-12 rep
Week 5-8 = 8 reps
Week 9-12 = 6 reps
Starting off with higher reps and slower tempo (speed of movement) can be useful to provide a foundation of endurance and muscular hypertrophy, which can then allow for more strength (and speed) to be built on top. It can also allow for bones and connective tissues to adjust to training and therefore help reduce the risk of injury.
Additionally, in the example above, after week 12, you could then start again from week one with the high rep range... Lifting heavy weights all the time isn't necessarily the best approach either.
If you are a golfer with a distinct in-season, then the off-season would include a higher reps compared to the in-season, which would be more based around the lower reps. Although, this would depend on things such as training history, age, goals, starting level of fitness/strength.
Here's an example of what a season leading to in-season/competition season might look like.
Month 1 = 12-15 reps
Month 2 = 8-10 reps
Month 3 = 6-8 reps
Season = 3-5 reps
For the example above, we would start off with higher reps to build and foundation of endurance and hypertrophy and build on that gradually increasing intensity as we work towards the season last reducing volume.
Our goal to improve golf performance should be to increase strength and power. In a training program, this would eventually include low reps and increased weight, however may well start with higher reps and lighter weights. Additionally, with power exercises, you wouldn't necessarily include them throughout the whole of a training programme. And certainly in the linear examples above, you wouldn't.