Background: Weighted vests (WV) worn during training can improve strength, endurance, and minimize the need for separate additional resistance training sessions. A WV provides external mass across the upper body and the chest while training. Due to the high versatility, WVs can be worn during a wide variety of exercises such as running and plyometric activities. Weighted vests are commonly incorporated by runners not only to complete running and restiance training together but improve performance. Extra demands placed on the muscular, respiratory, and cardiovascular systems when running with a WV can increase lower-body strength and endurance. Purpose: This study investigated the effects of weighted vest training (WVT) on maximal oxygen uptake (VO2max), non-invasive estimated cardiac output (CO), lactate threshold, (LT) concentration, and running economy (RE). Methods: Participants were screened for inclusion/exclusion criteria using the PAR-Q+/ePARmed-X+ questionnaires. Eighteen young female participants were randomly assigned into one of two groups, a 10% body mass weighted vest group or 2) a nonweighted vest control. Both groups completed two laboratory endurance training (ET) trials at pre- and post-, which consisted of three training sessions per week. Participants performed the two testing trials separated by >24 hours without using a WV. Laboratory test one (LT1) was an incremental treadmill test that determined VO2max and non-invasive estimated CO. Laboratory test two (LT2) consisted of a maximal lactate steady state (MLSS) treadmill protocol that determined LT concentration. Results: The covariate pre-VO2max had a statistically significant influence on post-VO2max, however there was no significance among the WV or non-WV groups. The covariate pre-CO had a statistically significance effect on post-CO, but no significance among the WV or non-WV groups was observed. The covariate pre-BL had a statistically significant result on post-BL, yet there was no signficance between the WV or non-WV groups. For RE, the main effect for the within-subjects was significant, indicating differences were observed between the values of pre-, mid-, and post-RE. A post hoc Tukey comparison for within-subject effects observed that pre-RE was significantly greater than mid-RE, pre-RE was significantly greater than post-RE, and mid-RE was significantly greater than post-RE. Conclusion: A structured endurance training program at a minimum of 3x per week at 30 minutes for 6 weeks, is adequate to elicit cardiovascular and metabolic adaptions as determined by VO2max, CO, and BL, and RE.
