T1 paramagnetic relaxation of radical ions induced by degenerate electron exchange (DEE) reactions is studiedtheoretically and experimentally. Our theoretical analysis shows that T1 relaxation time is well described bythe Redfield theory at arbitrary values of the characteristic DEE time τ. Longitudinal relaxation of norbornane(NB) radical cation is studied by means of the time-resolved magnetic field effects (TR-MFE) technique; therate constant of DEE involving NB•+ radical cation and NB neutral molecule is obtained. Advantages of theTR-MFE technique and its potential for measuring the short DEE times are discussed in detail.