The phrase "add toughness" is correct and usable in written English.
It can be used when discussing the process of increasing resilience or durability in a person, material, or situation.
Example: "To improve the performance of the athletes, the coach decided to add toughness to their training regimen."
Alternatives: "increase resilience" or "enhance durability".
By acquiring de Jong, United would attempt to address a glaring void in defensive midfield and add toughness to a lineup that has lacked an authoritative figure.
3. SACRAMENTO KINGS -- Brad Miller, the all-star center from Indiana, will add toughness, though he will not be nearly as effective out West.
He is one of several players added this season by Pat Quinn, the Maple Leafs' coach and general manager, to add toughness to a team that lacked it last spring when it was eliminated from the playoffs by the Devils.
Vasovic insisted he added "toughness and discipline and a winning mentality" to the side.
Odjick, who is out for two weeks, adds toughness and grit to the left side of any line.
Buffalo added toughness and talent with the free-agent signings of linebacker Takeo Spikes and defensive tackle Sam Adams.
When Purinton last played, Nov. 8, against the Philadelphia Flyers, it was as a forward to give the Rangers added toughness.
I've so been there, Emma… The lipstick Rebecca: Berry-stained with a hint of a smile, this juicy shade adds toughness – and will mask dreaded red-wine lips should she choose to indulge.
(5) When 20% fly ash + 2.5% fiber were added, toughness factor increases by 59% when compared to that of the 0% fly ash + 2.5% fiber; therefore, toughness factor decreases when fly ash content increases.
And, for a back who had relied on speed, adding toughness was a must.
Danny Fortson, a hard-nosed rebounder who was part of the Van Exel/Jamison trade, could add some toughness if healthy.
