Dissertation
OVERTRAINING THROUGH A NEW LENS: CHARACTERIZATION OF OVERREACH IN RECREATIONALLY ACTIVE ADULTS AND THE HORMETIC IMPLICATIONS
Washington State University
Doctor of Philosophy (PhD), Washington State University
07/2024
DOI:
https://doi.org/10.7273/000007046
Abstract
Background. Overtraining (OT) occurs from excessive exercise and inadequate recovery. Different pathophysiological mechanisms of OT have been theorized; however, the biological underpinnings of OT are unclear. Hormesis refers to a biphasic dose-response to stress. Accordingly, any biological system(s) overwhelmed by exercise-related stress may exhibit a maladaptive training response. Objectives: This dissertation aimed to 1) determine if recreationally active adults can experience OT and 2) identify potential markers of OT progression. Methods. Twenty-one recreationally active adults were randomized into training (TR, n=11) or control (CON, n=10) groups. TR participants underwent a three-week high-intensity training protocol designed to induce short-term OT (overreach [OR]) under laboratory conditions, then monitored over a three-week recovery phase. Both groups performed weekly exercise testing to evaluate performance and metabolic and cardiac responses to training. Sleep was monitored daily using actigraphy and surveys. A pilot proteomic analysis was performed in seven TR participants at baseline (BL), after training (MID), and after recovery (END). Results. After training, three TR participants were classified as OR (-10.3% ± 5.4% decrease in performance from BL), while TR participants without performance decrements were considered adapted (AD, n=8). Throughout training, OR subjects exhibited progressive decreases in maximum heart rate (-8.5% ± 6.4%, 180 ± 7.9 to 164 ± 4.6 bpm) and peak lactate (-33.6% ± 15.1%, 8.80 ± 1.47 to 5.86 ± 1.69 mmol/L) (P<0.05), which returned to baseline values during recovery. At END, peak aerobic capacity improved ~6% in all groups. Compared to CON participants, TR participants obtained less sleep (7.02 ± 1.03 versus 6.68 ± 1.20 hours per night, respectively), exhibited more variable sleep time, and were more likely to accumulate sleep debt (P<0.05). OR participants consistently reported higher illness symptoms than CON and AD (P<0.05). Proteomics identified 38 proteins upregulated at MID or END including 19 immune-related proteins (P<0.1). Conclusions. OR participants exhibited markers of OT compatible with both autonomic and immune dysfunction–different theories underpinning the OT response. OT is not a training response exclusive to elite-level athletes. OT as the upper endpoint of exercise-induced hormesis is a viable theory, which suggest that OT can occur from multiple pathophysiological mechanisms.
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Details
- Title
- OVERTRAINING THROUGH A NEW LENS
- Creators
- Thomas Gooding
- Contributors
- Hans C Haverkamp (Chair)Glen Duncan (Committee Member)Patrick Solverson (Committee Member)Laurie Wideman (Committee Member)David Nieman (Committee Member)
- Awarding Institution
- Washington State University
- Academic Unit
- Department of Nutrition and Exercise Physiology
- Theses and Dissertations
- Doctor of Philosophy (PhD), Washington State University
- Publisher
- Washington State University
- Number of pages
- 196
- Identifiers
- 99901152338301842
- Language
- English
- Resource Type
- Dissertation