Is 3 hours of exercise (spread out) too much for a day?

I'd like to start running for about half an hour in the mornings but I have gym cl and Muay Thai (Thai kickboxing) on Mondays, which adds up to a total of about three hours. They're spread out pretty evenly (running in the morning, Gym in the middle of the school day and Muay Thai after school at 5) but is that too much for one day? I don't do exercise otherwise on other days, apart from another hour of Muay Thai on Thursdays. Any advice and past experience would be greatly appreciated.