If you’re an average-framed guy starting with no visible abs — likely putting you somewhere around 18–20% body fat — celebrity PT Michael Baah says that “12–20 weeks is a realistic and sustainable timeframe”. So leg raises: lying face up, abs engaged and lower back pressed into the ground, lift your legs to vertical then lower to six inches off the floor. And Russian twists: holding your resistance item of choice, sit with your legs bent at 45 degrees, ankles crossed, then lift your feet six inches off the floor and rotate your upper body to touch the weight to each side – keeping those feet up.