New masters swim coach with different philosophy.

The new Master's coach philosophy is to do lower yardage and more IM. Lots of kicks (strengthen the core), lots of drills, and lots of toys (snorkel, skull finger paddles, regular paddles, zoomers, regular fins, *** stoke fins, finis tempo trainer, light weight kick board...) (disclaimer...I have not bought any of this stuff, just have the normal toys). I am in my 60's, have swum forever, many years in masters, raised age-group kids through college swimming, and am very confused. I am used to 10 x 100 or 5 x 200's or couple 500's, IM once in a while, option to swim IM or free, kicks as a set in a workout, you know what I'm talkin' bout. Now I am exhausted doing 90 minutes of kicks and sprints and only going 2000 yards. Flipping at the end of every set, using weight balls in the water, doing 6 x 100 *** stroke kick no hands, doing tandem training, example: swimming arm in arm with the other 60 year old doing fly kicks then holding his legs while I kick and he strokes, then vise versa. Now it is not always exhausting, but it seems always to be frustrating. Working hard is not the problem, but working hard doing fly kicks in 50 meter pools is frustrating. And my distance flog is suffering. Not just 4 x 50 fly kicks, but 10 x 50 fly kicks. It has been 4 months with new coach. Others say that they workouts are making them stronger for races and allowing them to be tougher. I worry about hurting my back, my shoulders, and not getting in my yardage. Fitness swimming should be challenging and fun; I am a wimp? Should I give it more time? I like my team!