increase weight and tone without looking bulky

Hi! I'm 5'5 female, 90lb, 29-22-32. (and according to online tests I have 13% body fat) I have a very small frame and quite an athletic figure; I have naturally defined abs, broad shoulders and a small waist; and I seem to put on muscle easily and it shows up quickly.

At the moment I don't do any physical activity at all and I want to tone up and increase my weight while still remaining toned. I'm pretty proud of my arms since I have defined deltoids and biceps. I used to have a very defined 6 pack since I used to do the plank everyday; but I haven't been doing it alot recently so I've got a vague 4 pack.

Are there any exercises that I can do to increase my weight? As far as diet goes; I eat pretty healthily; I have 3 solid meals and lots of protein bars and snacks. I have red meat about twice a week and fish every other day.

I am aware that I'm very skinny but this is genetic and the rest of my family are like this too

Firstly you would be dead at 13% body fat so your online tests are off by a mile.

The only exercise needed to gain weight is to eat more.

Thats not true at all; for females minimum body fat to function is 10%. I’ve also recently been to the doctors and they have confirmed my body fat is around 13% (12.7%). I am increasing the amount of protein / food I’m eating because I do want to gain, but I want to gain muscle and some exercises will allow me to do that but I’m unsure which ones.

Need to gain fat and muscle if thats your weight for christ sake... Thats gentitc? Dont tell me thats what you tell people either not realising that family members are heavier than that and arent that skinny and its only u, OR ur in denial and have an Eating Disorder?

What exercises to do will depend on where you want to gain muscle, increasing your weight through muscle gain is a long and slow process, so you`ll have to be patient.

Thank you! Do you have any tips for building core strength. I’ve been doing to plank and crunches but I was wondering if there is anything else?

Push ups, russian twists, proper form situps, ab roll outs, pull ups, dead lifts, yoga, leg raises, probably lots more but I wouldn't know the names of them.

Make sure you are progressing over time to keep building muscle. For some exercises like sit ups or russian twists you can do this simply by holding more weight. For something like push-ups you can elevate your legs more or do harder variations such as spiderman pushups or archer pushups and increase your number of reps.

Don't worry about getting too bulky. As long as you stay lean you'll never look bulky. Men train for years trying to put on muscle and 99% of them don't blow up overnight. As a female you'll be fine.

You are either skin and bone being female with 13% bf or you aren't 13%

You're female, you'll never get bulky. If you're serious about it, read the FAQ

Thats not true at all; for females minimum body fat to function is 10%. I’ve also recently been to the doctors and they have confirmed my body fat is around 13% (12.7%). I am increasing the amount of protein / food I’m eating because I do want to gain, but I want to gain muscle and some exercises will allow me to do that but I’m unsure which ones.

So you're telling me you're at the bf% of a bodybuilder without even trying? It's a disorder of some kind, metabolism varies by max 200 calories per day across normal people, so theres no such thing as 'naturally skinny' unless there are underlying health issues. How did the doctor find your bodyfat %? I hope it was a combination of underwater scans, DEXA scans, etc because some *****y scale isn't gonna cut it

I'm going to have to disagree with you there. There is such thing as naturally skinny and to say that metabolism differs by 200 max is preposterous. You have to consider basal metabolic rate which takes into to account height, age, activity level, thyroid activity etc.. I do have a slightly overactive thyroid that makes my metabolism faster than normal.

It was tested by callipers. I know that's not very accurate but it provides a good picture.

That's what I meant, you have a health issues that normal people dont, metabolism in normal people varies by 200ish calories max when they are the same height age weight etc,