An interventional study of Intensified Training in Amenorrhea, sponsored by USDA, Western Human Nutrition Research Center. Completed at 1 site in United States. Open to female participants aged 18 Years to 40 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2016-01-28.
Sponsored by USDA, Western Human Nutrition Research Center · Not applicable, Interventional, and Basic science
The investigators propose a prospective, longitudinal, department funded study protocol to evaluate whether changes in energy availability, during a period of highly intensified exercise training, will increase bone turnover markers and decrease ovarian function and exercise performance, in a dose-dependent fashion in competitive female athletes.
Female athletes participating in sports which emphasize leanness as a factor to success, while also imposing large exercise training loads, present a high prevalence of endocrine and metabolic alterations linked to low energy stores, including suppressed ovarian function and bone loss. Increased bone turnover resulting from low energy stores and suppressed estrogen production may hold the most adverse consequences for long term health, increasing the risk of premature osteopenia, while increasing the risk of stress fractures in the short term. Chronically low energy stores may also contribute to the development of overreaching and overtraining syndromes, characterized by excessive, lasting fatigue and long-term decreases in performance, which can compromise these athletes' health and athletic career. The investigators propose the first longitudinal study aiming to demonstrate the link between low energy status, impaired ovarian function, bone turnover and decreased performance in free-living, competitive female athletes. After a 4-week baseline period of habitual training, athletes will undergo 4 weeks of intensified training (IT), during which the exercise load is increased by 30% from their individual baseline load in order to sharply increase energy expenditure. As athletes will be let to freely adjust their food intake, the investigators aim to test the hypothesis that athletes will fail to adjust food intake sufficiently to match energy expenditure, and that the resulting decrease in energy availability (EA, energy intake - energy expenditure from exercise) will influence, in a dose-dependent fashion, the suppression of estrogen production, the increase in bone turnover and the severity of performance decrement. The IT period will then be followed by a 2-week taper (REC), in which exercise training volume will be reduced by 50% from baseline. The investigators will assess whether EA returns to baseline values, and characterize changes in bone turnover during this recovery period. It is hypothesized that any improvements in exercise performance resulting from IT + REC will occur in athletes who were able to remain closest to a balanced energy state during IT. Concretely linking EA to both performance and bone health may incentivize female athletes to adopt more adequate feeding behaviors for their activity level.
80 studies on the registry are indexed under Amenorrhea; 13 are open to participants now.
This study's enrollment of 18 is below the median of 60 across 43 interventional studies indexed under Amenorrhea.
Browse Amenorrhea studies →USDA, Western Human Nutrition Research Center is the lead sponsor of 53 studies on the registry; 1 is open to participants now.
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Exclusion Criteria:
Volunteers will increase exercise training by 30% from baseline
Behavioral: Intensified Training
Volunteers will increase exercise training by 30% from baseline
Change in energy availability (energy intake - energy expenditure of physical activity)
The investigators aim to capture the spectrum and variability of energy availability in endurance athletes under normal training conditions, describing in detail training regimen, total energy expenditure and nutrition habits during three distinct phases of training that are habitually followed by endurance athletes.
Time frame: Baseline (week 4), after 4 weeks of intensified training (week 8) and after a two-week recovery period (week 10)
Change in athletic performance
The investigators will measure the effect of energy availability on exercise performance during baseline, after 4 weeks of intensified training, and after a 2-week recovery, by measuring the relationship of energy availability to maximal oxygen consumption (VO2max) and 3200 meter time trial performance. The investigators will test the hypothesis that performance will be affected by changes in energy availability in a dose-dependent fashion.
Time frame: Baseline (week 4), after 4 weeks of intensified training (week 8) and after a two-week recovery period (week 10)
Change in ovarian function
The investigators will measure salivary estradiol and progesterone concentrations daily throughout the study, in order to test the hypothesis that ovarian function may be suppressed by intensified training and decreased energy availability.
Time frame: Baseline (week 4), after 4 weeks of intensified training (week 8) and after a two-week recovery period (week 10)
Change in bone turnover markers
The investigators will measure plasma bone turnover markers during baseline and at the end of the intensified training period, in order to test the hypothesis that bone turnover may be compromised by intensified training and decreased energy availability.
Time frame: Baseline (week 4), after 4 weeks of intensified training (week 8) and after a two-week recovery period (week 10)
Plan to share: Undecided
This study is completed, as verified in Sep 2015. You cannot join it, but the record below documents what was studied.
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USDA, Western Human Nutrition Research Center