Long ago (1998) a study was done involving elderly retired volunteers who were assessed after giving infants massage for a month versus receiving massage for a month themselves.

Results

(1) Participants reported less anxiety and fewer depressive symptoms and an improved mood

(2) Participants had lower pulse rates

(3) Participants had decreased levels of the stress hormone  cortisol

(4) Participants reported improved self esteem and a better lifestyle (e.g. fewer doctor visits and more social contacts)

These effects were stronger for giving infants the massages than receiving massages themselves, suggesting that the massager can benefit from simply giving massages.

Field, T., Hernandez-Reif, M., Quintino, O., Schanberg, S, & Kuhn, C. (1998).  Elder retired volunteers benefit from giving massage therapy to infants.  Journal of Applied Gerontology, 17, 229-239