Is it normal to feel sick after going vegan and starting a habit of bike riding?!

How long since you quite eating processed foods? Are you actually counting your calories?

If it's been a while since you changed your diet, you might well be short of protein. Protein is made up of amino acids. While meat, dairy and eggs contain all the amino acids needed for complete protein, most veggies only contain some of them (or weak versions). To get protein you need to eat a variety and alot of veggies every day so your body can combine the amino acids into the complete protein it needs. You need at least one, three is better, serving of legumes (beans) every day because only legumes contain one particular amino acid, lysine.

Iron in veggies is non heme iron and your body doesn't absorb it nearly as well as the heme iron in meat, eggs, dairy products. So you need to eat a lot of the iron rich veggies. The kicker here is that many of the iron rich, green veggies also contain oxalates which inhibits your bodys ability to absorb iron and calcium.

My guess is that you're not getting enough calories. 15 minutes is not really much of a workout on a bike. If you're getting enough calories and nutrients, you should be able to do more without problems. Keep a food diary or find an online calorie counter and see what you're actually getting. Junk food, chips, soda, don't count. They're empty calories.

too much water= it could be this. I can't drink water myself, it makes me nauseous, faint a lot and migraine.

It has to be the diet/excersieze, everything is now.

YOu say you're starving hungry and doing bike 15 minutes a night.
Crazy- just don't do it. You have to eat more to fill yourself- eat good food-
peanut butter and banan pita bread
wholewheat pasta with pesto sauce
brown rice, with chickpeas apples and peas.
pumpkin curry with naan
potato and leek soup
lentil and walnut pie with cheesy potato mash crust.

FOr snacking- pita with hummous, bagel with peanut butter and marmite,
tofu fried rice, black bean and cheese enchilads, soycheese and potato burritos with salsa.

Just eat good food, it sonds like you're not eating fats and carb- avocado with 7 grain bagel-
coconut rice, noodles and tofu with peanut sauce.

No need to eat lame food.

After I went vegan, I never experienced a sudden sickness (in fact, I've felt healthier now than ever, with more energy and a better weight!) I've also not gotten any colds or flus since I went vegan and I hope you experience the same good results. I'd check out this site for great vegan nutrition tips!
http://www.vrg.org/nutrition/

Go veg at your own pace; I went vegan over a period of 6 months to phase myself into it slowly and it must've helped!

vegan for the past 6 years and proud! :)

It is probably overexertion, but it could also be low blood sugar, or it could be unrelated. Just take it easy with the exercise if you are unfit. Start with something gentle like walking. Ask a doctor about what is appropriate exercise level for your age/BMI etc

LOL weak versions of amino acids, thats hilarious!!
Better open a window, you're only breathing a weak version of air when you're inside.

vegan biologist

I do not recall ever feeling sick, are you sure you are having enough to eat and also there is enough vitamin and are you drinking enough? It seems strange that you are sick from it.

No, it isn't.

You should see a nutritionist.