many have problems getting the training intensity high enough to progress.

here are few suggestions:

1) get chased by a bear, like in above video. 3 x 2 mins bear chase with 3 min rest is a good workout.

2) run your 5 km tempo in south african township at sunset chasing runners who are 2 mins faster than you;

3) do a swim race in white shark infested waters and suddenly find yourself all alone in the lead.

i heard of a guy who shaved off 2 mins of 5 km pb (to 17 something) doing the workout 2.

be creative with your training :)