My connected gym, is not connected, yet

After trawling the internet for some time, I still can't seem to get a defnititve answer for my project requirement.

The requirement is to have accelerometer sensors connected to gym equipment and the movement data to be sent to the cloud for analysis. Something like below:

+ 50 - 100 accelerometer sensors
+ Connecting to hub (Imp wifi? BTLE? ZigBee?)
+ Maximum battery life (Rechargeable? Disposable? 3 months of life? 1 Year?) Battery life very important
+ Collect data at central point (Raspberry Pi?)
+ Cloud analytics (Plotly? Log entry?)

Any input appreciated! =D>