Try adding four or five to the end of your workout to challenge your core a little more, or turn them into a standalone workout—try doing 12-15 reps of each exercise and then repeating the circuit (of four or five exercises) three to four times, to start. If you feel tension in your lower back during any of these exercises, stop and reset, making sure your abs are really engaged and that your back is not arched. You can also try starting with fewer reps. If you still feel discomfort, skip that exercise and try a different that allows you to keep your spine in a safer position. (It's also helpful to read up on which abs exercises tend to be irritating for lower-back issues beforehand if that's a concern for you.)
A. I’ll be honest, building muscle as a vegetarian is hard. There are nearly no clean sources of protein in a vegetarian diet. Soya Chunks come close but I’d recommend you stay away from a lot of soya if you’re a male due to it’s high oestrogen content. You can try incorporating more Beans (especially Rajma), Chickpeas, Hummus, Lentils (Dal), Sprouts, Tofu, Milk, Cottage Cheese (Paneer) and Cheese into your daily foods. Unfortunately, all of these foods either have higher carb content or higher fat content as compared to their protein content. Stick to the low fat or ‘made from cow milk’ variants.