Effects of prolonged running on physiological determinates in trained endurance runners with and without a running pack

Raw data deposited for project entitled 'Effects of prolonged running on physiological determinates in trained endurance runners with and without a running pack'Project abstractUltra trail running (UTR) involves races exceeding marathon distance on off-road undulating terrain and requires mandatory equipment and nutrition to be carried in backpacks. The effect of this load carriage on RE, other physiological metrics and durability of these across prolonged level and uphill running is unclear, particularly in well trained trail runners.Nine well-trained trail runners (age 30 ± 4.6 years, V̇O₂max 65.7 ± 9.1) performed two 100-min runs on a motorized treadmill at 90% of lactate threshold 1 (LT1) with and without a 2.5kg weighted vest. Running economy (RE), heart rate (HR), lactate (BLa), RPE, and core temperature were measured at three timepoints during level and short uphill bouts (10% gradient, 4 mins).Wearing a weighted vest found a significant condition x time interaction for HR at 55 (p = 0.01) and 96 mins (p = 0.02) compared to 14mins during level running, and a significant main effect for uphill running (p = 0.005). No significant effects of wearing a vest were observed for other parameters. Independent of condition, BLa, RER, and RPE, increased over time for both level and uphill running.This was the first study to assess the impact of load carriage on physiological durability on level and uphill running. Carrying a 2.5kg weighted vest elevated cardiovascular responses at notes timepoints for both gradients. But did not affect RE, BLa, RPE, Tcore, VE, or their durability over 100 mins. These findings offer practical insights into expected heart rate responses to modest load in well-trained trail runners.© the authors