Losing Weight

>>42431307
>Should I also start lifting weights and if so, where to start?

Did you not see the fucking dinosaur running back and forth when you got here?

don't fall the HIIT meme dude
you can't actually do HIIT efficiently unless you're already pretty fit
you're better off sticking to the bike because your cardio ability is probably pretty shit anyway

>>42431307
What kind of HIIT do you do? I'd suggest only steady-state cardio if you aren't rowing or swimming or something. Even if you're not getting shin splints or pain, running would put a lot of stress on your joints and shit. I'd wake up an hour earlier and go for a walk, or set the incline to max on a treadmill and the speed to 3 or 4mph. I'd also recommend you go on a 1000 calorie deficit until you hit 20% bodyfat, and then a 500 calorie deficit until you hit your goal weight.

>Should I also start lifting weights and if so, where to start?

Yes, you should. Start by watching form videos on Youtube and finding the /fit/ version of Grey Skull LP to do as a routine, but re-order the exercises so you're squatting second. Doing chins/rows immediately after OHP/bench is stupid.

>>42431307
>all I do is HIIT like 4 times a week
Enjoy your heart murmur/heart attack.

You don't NEED to do that intense that many times a week, and in fact you're probably DAMAGING your heart and cardiovascular system by overstressing it.

HIIT is grossly misunderstood. You need a basic level of aerobic fitness BEFORE subjecting yourself to stress of that intensity. It's no laughing matter, you could literally drop dead in the middle of a workout. Even pro endurance athletes spend months with basic aerobic conditioning before they start doing interval training at that intensity. What makes you think you're somehow special and can just bypass all that?