Do these phrases mean the same in the sentences? (on end, straight, in a row, in succession)
Do phrase in a and in b mean the same in the first sentence? Similarly, do phrase a, b, c mean the same in the second? If distinct difference is noticed, please point out the part so that I can learn.

Phelps burned his 12,000 calories easily while churning through the water at tremendous speed a.for hours on end/b. for hours straight.

The University of Connecticut's women basketball players set a new NCAA Division 1 record for consecutive-wins, a. becoming the first female team to win 71 straight games/b.becoming the first female team to win 71 games in a row/c. becoming the first female team to win 71 games in succession.

Question

Do these phrases mean the same in the sentences? (on end, straight, in a row, in succession)
Do phrase in a and in b mean the same in the first sentence? Similarly, do phrase a, b, c mean the same in the second? If distinct difference is noticed, please point out the part so that I can learn.

Phelps burned his 12,000 calories easily while churning through the water at tremendous speed a.for hours on end/b. for hours straight.

The University of Connecticut's women basketball players set a new NCAA Division 1 record for consecutive-wins, a. becoming the first female team to win 71 straight games/b.becoming the first female team to win 71 games in a row/c. becoming the first female team to win 71 games in succession.

Answer

a and b mean basically the same thing and are correct.
However, 'hours straight' is usually used for some definite period - "He practiced for four hours straight."
'Hours on end' is used something that went on for a long time, but with no definite duration mentioned.

In the second example, a, b and c are equivalent, though c might more often be expressed as "71 successive games"