Weighted Vests in Ultrarunning with Diego Jaén-Carrillo PhD #202
Episode overview:
Diego Jaén-Carrillo PhD is a postdoctoral researcher at Universität Innsbruck. Weighted vests are a common intervention used by both coaches and athletes, yet the existing research on weighted vests is virtually nonexistent. In this episode we discuss his pioneering study on weighted vests and their potential training applications for running and hiking.
Episode highlights:
(16:41) Research design: incremental speed and gradient test, 5-10% body weight vests represent in-race loads
(21:26) Stride length and stride frequency: both increase with speed, both variables were unchanged with weighted vests, individual preferred stride frequency and stride length
(29:08) Weighted vests for running economy: example ways to train leg stiffness, weighted vests training leg stiffness with greater specificity to running, ~5% bw is reasonable, application across a range of running velocities
Our conversation:
(0:00) Introduction: Diego’s pioneering work on weighted vests, application for coaches and athletes, study design
(2:06) Diego’s background: the state of research on weighted vests, academic background, discovering a collaboration and passion in running biomechanics
(5:12) Diego’s field of study: lower limb stiffness, spring mass model, relevant parameters, working at the University of Innsbruck and with researchers in Spain
(7:36) Why study weighted vests: observations from practice, noticing the lack of research, study setup
(10:39) Vest weight: mandatory kit in european trail races, athletes typically carry 2-5kg, normalizing vest weight to 5-10% body weight
(12:32) Caveats around how to use weighted vests: no research on how to train with vests, examples
(14:09) Study results: running kinematics are not changed with 10% body weight vests, 5% body weight vests stimulate leg spring stiffness and power output, caveats around using pace
(16:41) Research design: incremental speed and gradient test, 5-10% body weight vests represent in-race loads
(19:35) Recap of study design: 15 male subjects, Stryd power meter, application to research, graded exercise test, comparing tests with different body weights
(21:26) Stride length and stride frequency: both increase with speed, both variables were unchanged with weighted vests, individual preferred stride frequency and stride length
(23:32) Factors that change with weighted vests: 10% body weight vests change flight time, ground contact time, no significant changes with 5% body weight vests
(25:15) Leg spring stiffness: increased leg stiffness with weighted vests, regulation for elastic running, improving running economy and power, vests still reduce running performance overall due to changes in ground contact time
(27:02) Applications of weighted vests: common parabolic dose-response curve, weight is helpful until it interferes with your biomechanics, team sports example
(29:08) Weighted vests for running economy: example ways to train leg stiffness, weighted vests training leg stiffness with greater specificity to running, ~5% bw is reasonable, application across a range of running velocities
(33:44) Caveats to using weighted vests: build up to 5% bw, progressive overload, do not exceed 5% bw
(36:22) Running and walking during ultras: training mismatches, effects of distance and incline on walking during ultras, more is not better, considering long-term best interests for athletes
(40:07) Weighted vests for hiking: likely applications, train with the weight you expect to use during your race
(43:11) Theorizing future research: investigating if there is a case for overload regarding weighted vests and hiking, mechanics of walking versus running
(45:16) Wrap-up: where to find Diego, links in the show notes
(47:02) Outro: giving thanks, check out Research Essentials for Ultrarunning, share the KoopCast
Additional resources:
SUBSCRIBE to Research Essentials for Ultrarunning
Buy Training Essentials for Ultrarunning on Amazon or Audible
Information on coaching-
Koop’s Social Media
Twitter/Instagram- @jasonkoop