  Cold Helium atoms are a unique system where a single excited three-body
Efimov state occurs, naturally, without the need for an external magnetic
field. While three-body bound state energies of cold Helium atoms have
previously been investigated, recent experimental techniques have allowed their
structure to also be studied. The weak interaction between Helium atoms leads
to a helium-helium (dimer) scattering length, $a$, much larger than the
helium-helium effective range of interaction, $r$. This feature is exploited in
a theory that systematically expands observables in powers of $r/a$, known as
short range effective field theory (srEFT), which has been used successfully to
investigate properties of cold atom systems. Using srEFT we investigate the
average bond length of atoms in the three-body ground state and excited Efimov
state of cold Helium atoms. At leading-order (next-to-leading order) in srEFT,
we find the average bond length of the $^4$He trimer ground state is 8.35(33)
\r{A} (10.29(2) \r{A}) and the average bond length of the excited $^4$He trimer
Efimov state is 103(4) \r{A} (105.3(2) \r{A}).
