Interval Training

Dynamic Mobility Warm-up
Then:
Sprint Specific Warm-up Drills
Then:
5x100m Sprints
Light Jog to start position and start the next sprint as soon as you get there.
Then:
5x50m Sprints
Walk back to start position and start the next sprint as soon as you get there.
Then:
10x Burpees to Knee Tucks +
10x Hammer Work on Tyres +
10x Ab Roll outs
3 rounds in total. Rest periods between each tri-set 1 minute.
Then:
Cool down and Stretch

Core strength is not measured by an aesthetic set of six-pack abs. However there is nothing wrong with striving to achieve an attractive physique, if you continue feeling good about yourself and most likely to continue training.