Purpose: Monitor changes in force production, running economy (RE), and running kinematics (RK) in a highly trained marathon runner after beginning a strength training (ST) program. Methods: One marathon runner (M, 27 y, 165 cm, 53.3 kg, VO2pesk 67.43 ml/kg/min, PR 2:33:13) with no history of ST completed a 12-week block periodized ST program. Baseline and reliability testing was conducted over a two-month period prior to ST. The completed ST RPE and work (volume load*displacement) and running volume (km/wk) were monitored over the 12 weeks. The athlete performed an isometric mid-thigh pull to assess peak force (PF, N), rate of force development at 250 ms (RFD250), and net impulse at 250 ms (NI250) during baseline and throughout ST. The athlete performed a steady state test on a treadmill instrumented with the OptojumpTM optic sensor system to assess RE (ml/kg/km) and RK during baseline and throughout ST. Impact of the ST program was assessed by percent change of the variables during the taper from the baseline average and by the odds of a true change using the typical error and smallest worthwhile change. Results: PF improved (120:1 odds) by 17.11%, RFD250 improved (22:1 odds) by 24.73%, and NI250 improved (10:1 odds) by 16.70% before competition. Ground contact time decreased (7:1 odds) by 2.57%, flight time decreased (1:1 odds) by 1.49%, step rate increased (2:1 odds) by 2.28%, and step length decreased (57:1: odds) by 2.21%. RE improved (3:1 odds) by 2.09%. Conclusion: Improving a runner’s maximal strength and rate of force development may positively influence RK and RE.