Some interesting ideas here... All of them have some validity, some more than others...

Shinkicker - as John noted, jigging 200m hoping for a hit at any moment is probably not the best use of your energy. Use your sounder to work out where the fish are holding. When they are properly on the chew you can normally drop to kings and get a hit within 3 or 4 winds.

Failing that there is some value in getting jig fit.

As others have noted there is nothing better than jigging itself to get you fit for jigging. It is a highly specific action and one that is very hard to replicate in the gym. The only problem with this is that not many of us can go jigging often enough to actually gain a positive training effect from it. Before the arrival of my kids I was lucky enough to be able to fish at least twice a week, and when school holidays were on that might go up to 5 times a week!

Over the last 6 years or so as I became more time poor my fishing went down and I would only get out once every few weeks. Straight away I started to struggle in terms of being able to jig as hard and as long as I could before. This was annoying as when I got the chance to go out I wanted to make the most of it... Not being absolutely stuffed after a few drops! So in response I started to think what I could do in terms of specific jig fitness exercises.

As others have mentioned the elastic Theraband or Cross fit type bands are very good for training with. From my experience it is the front part of the shoulder (anterior deltoid) that suffers the most fatigue, coupled with a bit of bicep, but not much. It should be noted that all of my jigging is done with Spin gear so it might be slightly different for oh, but I doubt it.

My initial routine consisted of using a Theraband. I fish left handed. I would tread on one end of the band with my right foot, and then stretch the band so that it was under a pretty good load when my right arm was bent at 90 degrees at the elbow, with my forearm parallel to the floor. From here I would do sets of arm lifts to mimic the jigging action. Make sure that you have your hand angled as if you were holding a rod. Typically I would do 100 reps and then swap to the other arm. I would just keep swapping arms but would look at doing 500-1000 reps per arm. Even with a soft band the resistance is waaaaay more than you would experience jigging. It made quite a difference and certainly made
long jigging sessions easier.

I have since progressed to using mini dumbbells which to be honest are better. What I now to is hold a 1 or 2 kg in each hand. Basically I will put my hands together as if I were holding the rod in my right hand and reel in the left and simply do a jigging action with the dumbbells in each hand. Make sure your rod hand/arm is in the same position as it would be when you actually jig. Again I will do sets of 100 reps - ie 100 jigging actions holding the weights. Have a rest or go and do something else and then come back and do some more. Think of how many times you might lift the rod in an all day jigging session... That's a lot of reps, so do as many sets as you can. With a 2kg weight you will get a burn fairly quickly.... BE WARNED THOUGH - YOU WILL LOOK LIKE A TOOL!

If you do this a few times a week you will be amazed at how much difference it makes. It's no substitute for fishing but it will get you better prepared for when you can go.

However I would say that IMO the single biggest factor that contributes to jigging efficiency and the ability to be able to jig for a long time without getting tired is core strength, or rather for most people a distinct lack of it. I am very fortunate that I am able to keep fit through my job, but for most people who have a desk job or a sedentary lifestyle, their core strength and lower back strength is non-existent. If you strengthen up your core all of a sudden you will find it much easier to jig, especially for long periods.

Aerobic fitness undoubtedly plays a part, but from my experience the local muscular endurance of your shoulders is more significant, as is having a strong core to be able to support and hold good posture whilst you are jigging.

Dead lifts and bent over rows - great if you have some experience, but I would suggest steering clear otherwise. A dead lift is a great way to stuff your back pretty quickly.

Last point, unless you really have to use it, ie there's a really fast current/drift, drop down to lightest gear you can get away with. I used to always jig with 400g jigs and a big heavy reel... I still do that when I have to but my go to set up is now a PE4 rod with an 8k Stella. Generally I use 250-300g jigs - I can comfortably jig this set for hours on end (literally) - so shinkicker maybe consider whether you can lighten the load as well. The new lighter rods and reels are well capable of putting out some serious hurt but are a pleasure to use for long periods of time.

Failing all of the above some cement, a box of Heinekens and some time on pornhub will probably improve your longevity of jigging stroke as well

Tight lines

I knew core strength was significant but I didn't realise how hard it actually works until I went jigging a couple of days after a particularly brutal training session I had been put through. I was literally wincing with every lift of the rod and Rock and roll of the boat as i had to activate my core to stabilise myself.

The day after a big day offshore on a rough day you can really feel it.

That being said though - one of the reasons jigging appeals to be so much is that its a physical challenge in itself, especially if when you have one of those dream sessions when you hit loads of decent fish and you leave them biting because you are too buggered to catch anymore. Nothing beats that!

And I should be drinking more Hienieeeees