I think that the most successful combat athletes are masters of functional strength training methods. They have to train in a fashion that is going to be transferable to their sport, if not, it will be a waste of time and energy for them. Most combat athletes compete in weight classes so the muscle they gain will have to be a type of muscle that is useful, functional for their sport, and not add extra useless dead weight to their system.
There are various ways to build a type of functional strength that is transferable to martial arts. Some include kettlebelles, macebells, battle ropes, calisthethics, etc. Gymnastics in my opinion is a great tool for combat athletes to build a functional type of strength that is useful for them and please see my article on this topic titled "Gymnastics: The Secret Cross Training Method of Successful Combat athletes"
One of my favorite drills to build neck, back, and lower body strength is the wrestling bridge flips. Years ago one of my students went to Fedor Emelienenko's MMA training seminar. For those who do not know, Fedor was a one the best Mixed Martial Art Athletes that ever lived and he was unbeatable for 28 fights until 2010. Fedor was also a multiple time World Champion in Sambo and Russia National Champion in Sambo, Fedor, during his career ,was known for not training with heavy barbells. He always stated in interviews that he used kettlebells and calisthenics mostly. This was during an era that most athletes, trainers and coaches did not know what a kettlebell was in the western world. My student who attended Fedor's seminar told me that during the warm up Fedor demonstrated bridging exercises and spoke about the importance for neck strength and grapplers. Right after showing some basic drills Fedor moved on to neck bridges with backwards and frontward flips. Fedor was able to do these flips repeatedly without any trouble at his weight of 240 lbs. My student said the whole room was surprised the way he moved and performed this drill at ease as if he was a 60 kg light weight grappler.
When my student spoke to me about this, I was not too surprised. While I was training for 10 years in Eastern Europe, I was aware of combat athletes always working on acrobatic, gymnast type of exercises and perfected them as a part of their training. I have seen very successful sambo practitioners practice this exercise for countless repetitions in the gym. All these sambo practitioners also had very power suplexes and they taught me this exercise as a supplementary exercise to improve my suplexes. I think acrobatic, gymnastic exercises like this and kettlebells can arm a combat athlete very well and develop a super functional strength that is transferable to sports. I highly believe that this is something that helped Eastern European athletes like Fedor very much.
I used this drill during my conditioning practices and I noticed that my students who perfected this became more explosive. They had more control and power during suplexes and they felt more confident during the execution of their suplexes. I believe heavy squats, power cleans, and snatches have their place but I firmly believe that exercises like this are super beneficial and mandatory for combat athletes. When you put your self in a back neck bridge position, some of your muscles shorten and some lengthen. This is a very odd position to be in, yet very odd to generate enough strength to make the flip, especially the back flip. You have to explode and all of your muscles will have to coordinate simultaneously to make it happen. In grappling sports athletes always end up in odd positions in which they need to explode and be agile at the same time, especially during countering maneuvers. It is very rare that grappling athletes are in a squatting or a deadlifting type position. The nature of this exercise makes it a perfect one for grapplers. Doing the front flip is very simple, but performing the back flip from bridge position right after is quite difficult and this is the one exercise that provides the benefits and is what this entire article is about. I noticed that my students who perfected this, not only become better at suplexes but they also become more explosive athletes in general. Their legs become almost "spring" like and I also notice that their double leg take downs become a lot more successful. This may be due to the fact that they can generate more power to aid their execution of the double leg takedown technique.
Be careful with this exercise and make sure you do not strain your neck. If you have trouble doing the back flip you may want to use a wall to push off until you develop the necessary strength to perform it by pushing off the ground. Also when you push off the ground with your feet, you may want to lead with one leg to make it easier and with time try to do it by jumping with two fixed feet. I hope this makes sense and please shoot me an email if you have any questions.
Check out the videos below which demonstrate this exercise.