Your body will become like a stagnant pond versus a clear bubbling stream. Exercise is necessary to oxygenate cells, accelerate the expulsion of accumulated toxins, and flush out your circulatory system.
No, jogging isn’t necessary, nor is exercising so hard that your chest hurts. Just increased breathing and breaking into a light sweat by maintaining elevated heart rate for at least ten minutes per day is enough.
Simple home exercises like pushups, bicycle crunches, barbell movements, and leg lifts or squats (if you don’t have weak knees) do the job. Whatever works.
And most importantly, get enough sleep — every night.
Some people view sleep as something that gets in the way of living, but that’s like saying coming up for air gets in the way of diving. Sleep is when the body repairs itself and charges up with physical and vital energy. If you sacrifice sleep for trivial reasons, you will burn the candle at both ends. Your immune system will suffer for it, you will age faster, get sick more often, have lowered creativity and initiative, get stressed and irritated more easily, and become more zombie-like.
Get the sleep you need to feel your fullest, and take a short nap if you hit an energy slump during the day.