The exercises described here are diverse and interesting, take up little time, and give you the MAXIMUM possible result in a short period.
1. Iron Abs in 8 Minutes a Day
This is an excellent method for training your abs, consisting of a series of exercises (11 types of exercises) that are continuously alternated with each other. The exercises are selected in such a way that you can rest during the workout, since different parts of the abdominal muscles (including the oblique muscles) and the neck are loaded. As a side and positive effect, especially for guys, it also trains the front neck muscles. I don't put my head on the floor at all during the workout. My neck burns at the end. Video of Iron Abs in 8 Minutes.
With time, you may find the load in this video insufficient)) For example, I started increasing the time and holding an 8 kg dumbbell behind my head to get more effect from the workout.
You can alternate this series with abdominal training on the bar outside, for variety, in home conditions. Or, perhaps, when it's raining or cold outside.
2. Ab Wheel Roller
This exercise works out your abs "among other things" as it almost loads all the muscles in your body. The ab wheel roller is great for working out arm muscles and joints, back, abs, and even leg and chest muscles. Start by doing it on your knees, lowering yourself to touch your chest to the floor. When you can do 3 sets of 20-25 reps "smoothly" move on to doing the exercise with straight legs.
TIP: When transitioning from exercises on your knees to exercises with straight legs, to make the transition easier and smoother, bend your arms slightly at the elbows in the most critical points. When you get used to it and your joints finally strengthen, you can do it with straight arms.
A wonderful way of physical training, one of the most effective ones that I know of. I recommend that you master it.
Afterword
Of all the methods I know, I believe that these 2 can really help you build and sculpt your abs. Moreover, the exercises are varied and interesting, do not take much time, and yield the MAXIMUM possible result in a short time.
Advice: If your abs are weak and untrained, start with the "8-minute iron abs" exercise, and when you have mastered it perfectly (the benchmark for "perfection" is doing it without a video, on the clock, knowing all the exercises and their sequence by heart, and holding an 8 kg dumbbell over your head with your arms). And only after that, you can smoothly transition to the roller exercise. It's even better to add some pull-up exercises here.
The exercises described above have been tested repeatedly, and their effectiveness has been fully evaluated by me and my friends. That's why I find it appropriate to write about them here. Maybe they will be useful to you...
Remember - "it's better not to work out than to overtrain." It's a homemade proverb, but it comes from my own experience (and stupid mistakes).