Electronic Theses and Dissertations



Document Type


Degree Name

Master of Science


Health Studies

Committee Chair

Max Paquette

Committee Member

Jason R Franz

Committee Member

Douglass W Powell


Endurance running exposure alone may not be sufficient to slow the age-related decline in plantarflexor function that is also thought to contribute to declines in running economy. Thus, it is important to identify interventions beyond running alone, plantarflexor-focused resistance training, that could help maintain plantarflexor function and “youthful” metabolic costs in aging runners. PURPOSE: To assess the influence of three types of resistance training interventions on running economy (RE), plantarflexor function, and Achilles tendon (AT) stiffness in middle-aged runners. METHODS: Twenty-six middle-aged runners (51±5 yrs) participated in one of three different 10-week resistance training interventions: 1) heavy resistance training, 2) heavy resistance training + plyometrics, and 3) endurance resistance training + plyometrics. Laboratory testing for RE, peak plantarflexor torque, and AT stiffness during isometric contractions occurred before and after the interventions. A mixed-design repeated measures ANOVA was used to address our research question and paired and independent t-tests were used to compare time and group effects, respectively. RESULTS: Relative (to V ̇O_2max) running economy (-2.4%, p=0.016), AT stiffness (26.1%, p=0.002), and peak isometric plantarflexor torque (26.4%, p=0.001) improved over time with no interaction or group effects. No significant interaction, time, or group effects were observed forV ̇O_2max and peak plantarflexor torque, peak positive ankle power, or positive and negative ankle work while running. CONCLUSION: Our results suggest that resistance training improves running economy for middle-aged, recreational runners, potentially by inducing increases in AT stiffness. We present a novel finding that multiple modalities of resistance training increase AT stiffness and improve running economy in middle-aged runners.


Data is provided by the student.

Library Comment

Dissertation or thesis originally submitted to ProQuest.


Open access