Gainsay:
- take exception to; “She challenged his claims”
- challenge, dispute
- contest, repugn, contend - to make the subject of dispute, contention, or litigation; controvert

verdure
n.
1.
a. The lush greenness of flourishing vegetation.
b. Vigorous greenery.
2. A fresh or flourishing condition: the verdure of childhood.

http://www.thefreedictionary.com/verdure

thew
n.
1. A well-developed sinew or muscle.
2. Muscular power or strength. Often used in the plural (thews).

adj. thewy

http://www.thefreedictionary.com/thew

vim
n.
Ebullient vitality and energy. See Synonyms at vigor.

http://www.thefreedictionary.com/vim

brio
n.  Vigor; vivacity:
“She tells their story with brio and a mixture of sympathy and tart insight” (Michiko Kakutani).

http://www.thefreedictionary.com/brio

solicitude
n.
1. The state of being solicitous; care or concern, as for the well-being of another. See Synonyms at anxiety.
2. A cause of anxiety or concern. Often used in the plural.

http://www.thefreedictionary.com/solicitude

anneal

–verb (used with object)
1. to heat (glass, earthenware, metals, etc.) to remove or prevent internal stress.
2. to free from internal stress by heating and gradually cooling.
3. to toughen or temper.
4. Biochemistry. to recombine (nucleic acid strands) at low temperature after separating by heat.
5. to fuse colors onto (a vitreous or metallic surface) by heating.

http://dictionary.reference.com/browse/anneal

Other words:

bulwark, buttress, lynchpin, clout, efficacy, moxie, puissance, sinew, pep(piness), stimulus, fury, impulse, instinct, fortitude, tenacity, stoutness, rejuvenate, invigorate, robustness, brawniness, heftiness, chirpiness, sprightliness, spiritedness, elan, avidity, earnestness, frenzy, fever, gaiety, rapture, aloofness, pizzazz, virility, vitality, flamboyance, panache, elan, dashing, spunk, dazzle, flicker, gleam, glint, twinkle, sparkle, coruscation, scintillation,  grit, indefatigable, enterprise, vigour, gusto, zest, zeal, cupidity, avarice, covetousness, rapaciousness, acquisitiveness. voracity, hunger, ravenousness, thirst, yearning, yen, gluttony, appetence, propensity, proclivity, alacrity, ebullience, buoyancy, gumption, guts, disquietude, stultifyingly monotonous.