The Merseyside club were superb in the first half of Wednesday's clash at Goodison Park and took a richly deserved lead as Romelu Lukaku lashed home Kevin Mirallas' cut-back.
However, they could not muster the same intensity after the break as Hull grew into the contest and hit back through impressive substitute Sone Aluko.
Steve Bruce's side, in truth, had the better chances to win the game, and with an extended schedule to compete with this season as Everton compete in the UEFA Europa League, they looked jaded in their third game in seven days.
And with the busy festive period to come, Martinez issued a cautious assessment of his side's inability to find a second wind.
He said: "Across the two halves I thought we saw a Hull City side coming very clearly to make things difficult to be very strong, they had two very energetic banks of four.
"We were fantastic first half. We got through the lines really well. We showed a real good intent after we scored
"Second half it was completely different. The approach of Hull City it suited their role.
"Leighton Baines comes off, we got unsettled in our rhythm and in the middle of that, Hull City had one shot on target and got the equaliser.
"After that we couldn't find any energy. The way we are as a team, it's very difficult to be creative when you haven't got the energy.
"In the first half we did enough to win the game, but you don't win games with one-goal margins."
‘Arteta, Alonso, Emery, me… none of us were physical players – we needed the understanding of the game. That probably helped us move into management’: Premier League boss reveals reasons for natural career progression
‘England have the players to win the World Cup – it’ll be tough for Thomas Tuchel to do a bad job, with the squad he has at his disposal’ Former Three Lions winger backs new boss after gentle qualifying draw
