It seems destiny is offering me openings in the old-school gimmicky world of questionable “training” equipment. That said, I was initially wrong re chest expanders and chest krushers (old strongman useful accessory tools).
I have been offered an old Bullworker device for free. Having checked some clips on Youtube it looks it has a minor following, and a few prominent influencers does not dismiss it.
Appearantly, it’s the isometrics that is a selling argument - where a 7 sec isometric is supposed to result in a significant effect. I’m not buying this, as I belive isometrics needs to be longer (30-60 secs) in order to be effective.
Anyway, I will probably try the Bullworker for fun, and was wondering whether anyone here has anything positive to say about it? Is it a useful plan B during travel?
I had one of these back in the last 80’s, think it was my dads or one of my uncles gave it to me. I am not sure it would really do much in terms of muscle or strength development especially as you are already doing resistance training with weights. As @SkyzykS says, I would think of this as something to keep you amused or to play with and see if you can fully compress it via pushing it together or using the bands and pulling. You never know after 6 weeks you might turn into Charles Atlas.
Strength gains are joint-angle specific. However, strength gains from isometric training at long muscle length transfers throughout the whole ROM
Hypertrophy adaptations from isometrics are minimal unless training at long/extreme muscle lengths
Maximal strength adaptations take place from maximal isometrics 3-7s in length
Hypertrophy adaptations from isometrics occur from ~20s upwards. However, longer isometrics are more likely to be limited by pain tolerance and other factors than the muscle itself, so durations longer than 45s are not recommended