Isaac wants to win a 5k running race, but because he spends several hours after school playing video games, he doesn't have time to train. what type of goal-setting challenge is isaac facing?

If  Isaac wants to win a 5km running race he must train and must achieve some goal before the race (to run 5km in some time frame).
But if he does not train and instead of that  he spends several hours after school playing video games he is facing several challenges in the goal- setting: the goal is not realistic (if he does not train he will not achieve his goal).
In order you achieve your goal the goal must be realistic (it is possible to achieve the goal in the time frame you have set),  specific, measurable,  attainable, you should review your progress, you should not underestimate others, the goal should not be negative...