Adiabatic RF pulses can be used for simultaneous compensation of B1 RF and B0 field inhomogeneity during continuous wave constant amplitude spin-lock. However, due to a relatively long duration of the adiabatic RF pulses, the relaxation effect during the adiabatic RF pulses can introduce a non-negligible effect on the conventional mono-exponential model used to describe T1rho relaxation during the spin-lock. Consequently, quantification using the conventional model can introduce errors. Based on Bloch equations, we derived that such relaxation effect contributes a DC component to the conventional mono-exponential model. We used simulation and in vivo MRI scan to demonstrate our theory.