Text

theses

Background: A balance between training stress and recovery is essential for successful athletic performance, thus the development of an evidence-based approach to monitoring changes in stress and recovery is critical. The purpose of this study was to combine analysis of nutritional biomarkers with mood, sleep, and performance assessments to examine changes in recovery and training status throughout a competitive season. Methods: Division I female collegiate soccer players (N=25; Mage=19.4 + 1.4 yrs; Mht= 167.9 + 6.3 cm) participated in blood draws at the beginning of preseason (T1) and every four weeks after within ~18 hours following a game (T2-T4). Athletes arrived well hydrated following an overnight fast. Several performance tests were administered prior to the start of preseason (PT1) and end-of-season (PT2). These included body composition (body fat (%BF), fat free mass (FFM), and fat mass (FM), vertical jump (VJ), and VO2max. Glutamine (Glu), Taurine (Tau), Tryptophan (Trp), Phenylalanine (Phe), Iron (Fe), Vitamin B12 (VitB12), Vitamin D (VitD), and Omega-3 (n-3FA) were analyzed. Mood and sleep were assessed using the Multi-Component Training Distress Scale (MTDS), and the Pittsburgh Sleep Quality Index (PSQI), respectively. Workload was assessed using several measures including heart rate data, distance covered (Dis), caloric expenditure (kcal), caloric expenditure (kcal/kg), and training load (TL). Additionally, counter movement jump (CMJ) was assessed at the beginning of practice at each time point. RM MANOVAs with univariate follow-ups were conducted with significance at P<0.05. Results: Weight was maintained throughout the season despite an increase in LBM (P<.05) and a decrease in %BF (P<.05). VO2max and VT significantly decreased (P<0.05). CMJ was maintained from T1-T3 but began to decline at T4. Measures related to training load decreased following T1-T2 (P<0.05; ESTL=-2.86, ESDis=-1.33, ESkcal=-2.22, ESkcal/kg=-2.78) and remained depressed through T4. Total mood disturbance increased from T2-T3 (∆Mood= 6.4 ± 1.9, P<.05) and remained elevated. There was an initial decrease in perceived stress (PS) from T1-T2 (P<0.05, ES=-0.95) that was followed by an increase at later portions of the season (P<0.05). No changes in sleep quality (SQ) were seen. Sleep duration (SD) increased from T3-T4 (∆SD=0.4±0.1, P<.05). n-3FA increased from T1-T2 (∆n-3FA= 0.5 ± 0.1 %, P<.05), then returned to baseline. VitD decreased from T1-T2 (∆VitD= 6.8 ± 1.4 ng/mL, P<.05) and continued a downward trend. VitB12 increased from T1-T3 (∆VitB12= 72.0 ± 18.8 pg/mL, P<.05) and remained elevated. Fe decreased from T1-T2 (∆Fe= -29.6 ± 7.9 mcg/dL, P<.05), before returning to baseline. There were no significant changes in Phe or Tau (P>.05). Trp decreased from T2-T3 (∆Trp = -10.9 ± 4.3 umol/L, P<.05) and remained depressed. Glu increased from T1-T2 (∆Glu = 82.1 ± 23.1 umol/L, P<.05) then returned to baseline. Conclusions: The highest training stress occurred during the initial training block (T1-T2) and resulted in negative changes in VitD and Fe. The greatest mood disturbance occurred at the end of the season when Trp levels also declined. Trp, a precursor of serotonin, may provide a mechanism for understanding changes in mood typically reported with overreaching. Decreases in VO2max and VT also occurred at the end of the season which corresponded to tournament play. SQ may be more important for full recovery than SD, as increased SD did not mitigate changes in mood. These results highlight the stress experienced by a collegiate athlete during a condensed season including increased physiological disruption around tournament play. Further, this holistic approach to athlete monitoring may provide greater insight to assessing accumulated stress both on and off the field by tracking physiological, nutritional, and psychological changes throughout a season.

ETD_10216

M.S.

Includes bibliographical references

doi:10.7282/t3-tgrm-5g16

ETD graduate

The author owns the copyright to this work.