thanks for the replies that's made me feel better

Did my first marathon 2 weeks ago the white peak marathon it was very hot finished in 4.25 felt ok the next day no aches or stiffness just a bit of chafing but i've been out running about 6 times since around 6/7 miles taking it steady but i don't seem to have energy feel very slothlike am wondering is this normal ? I'm 50 years old been running for about a year