Through the centuries, there has been Halachic debate with regard to the Beracha of Hanoten La’Yaef Koach. While all agree that thanking Hashem for giving strength to the weary every morning is a praiseworthy idea, there have been divergent opinions as to whether it is proper to recite this Beracha.
The Beracha is first mentioned by the Tur (Rabbenu Yaakob Ben Asher, 1269-1343, OC 46) who does not cite its source. Maran, in his Bet Yosef, disagrees with the Tur and wonders how one can use Hashem’s name in a Beracha , which was not recorded in the Talmud. Therefore, Maran rules in the Shulhan Aruch that one should not recite it. Based on this, the Vilna Gaon (Rav Eliyahu of Vilna, 1720-1797) and the Peri Hadash (Rav Hizkiya Da Silva, 1656-1695)also did not recite the Beracha.
On the other hand, the Hida (Rav Haim Yosef David Azulai, 1724-1807) cites a tradition from the Ari Hakadosh (Rav Yishak Luria of Tsfat, 1534-1572) that this Beracha should be recited. He and the Ben Ish Hai (Rav Yosef Haim of Baghdad, 1833-1909), therefore, ruled to say the Beracha. He argued that if Maran had known that the Ari HaKadosh ruled to say the Beracha, he too would have agreed. Even if Maran would disagree, and thereby create an uncertainty with regard to the Halacha, the Hida and the Ben Ish Hai hold that the general principle of "Safek Berachot L’Hakel" (When in doubt, be lenient and do not recite the Beracha) does not apply to instances which the Ari Hakadosh would say the Beracha.
Hacham Ovadia also rules to say the Beracha. However, he takes issue with the Hida’s assumption that Maran would have agreed with the Ari Hakadosh if he would have seen his opinion. Therefore, he bases his ruling on the fact that the common minhag (custom) in Am Yisrael is to recite the Beracha. This is indicated by the fact that all of our Siddurim, without exception, have the beracha. Hacham Ovadia says that the principle of "Safek Berachot L’Hakel" does not apply when the common custom is to recite the Beracha.
It should be noted that there is no "middle road" in this dilemma. Either the Beracha should not be recited or it must be recited. One cannot say that is "reshut" (optional). Once it is permitted to say Hashem’s name in the Beracha, it would automatically become required.
SUMMARY: One should say the Beracha of "HaNoten La’Yaef Koach."