Water fasting and heart rate

Hi, I've got a question for experienced water fasters. I'm fasting and have gone 25 hours now without food, only water intake. I am noticing that my heart rate has gone up, and my heart is beating harder, even though I'm just laying down and trying to sleep the hunger away. Is it normal to get your heart rate up? I know fasting sometimes gives certain people a boost of energy, but I still feel lethargic. Also right now I've noticed that my hands are shaking like im hopped up on too much caffine. I hope this is normalish. I want to go 4 days on this fast.
Let me also tell about myself cause it might help. I'm 23 years old, about 180 lbs., generally phsyically fit (that is, I work out five days a week), I have done one day fasts before about 3 times. To prepare for the fast I ate a few small meals of only fruits and veggies the day before I started, I also worked out a lot when I started the fast to burn up any glycogen in my system to get straight into ketosis for the fast. Also because I really like working out.
So yeah, if you could tell me that it is normal to tremble and have your heart rate kicked up in the beggining of a fast that would be fantastic, if it's not... well, thats okay too. Tweet