G' Day,
The Back and 80% of the other Surf Ski Paddling problem we hear about today be it on Flat or open water would end with a good Core, power from the Core is needed in all sport and Life, look at our sport with most paddling in what use to be called the kayak slump. a strong Core is key to living life at all, today with the over weight problems for 70% and Sitting or Standing most of the day being the norm in the work place life sucks. so as not to burn time a good trainer is a must for Core training also as not to blow wasted time.
Cheers Joseph
Joseph