I wouldn’t say days for muscle recovery. That would be for CNS recovery which goes along with very high intensity voluntary exercise as oposed to EMS of any intensity. EMS recovery could be as short as 4 hrs or so.
In reference to EMS stimulating GH, the cliic I worked with found that growth was stimulated in CP children treated with extremely low intensity EMS overnight for prolonged periods. These children on average moved from the 20th percentile to the 50th percentile of growth in about a year.
These effects could be systemic as above or localized on a treated area in some cases.