Energy Deficit and Hormone Suppression: The Hidden Threat to Performance
- projectunlaced
- Aug 24
- 2 min read
Ever wonder how a young athlete’s energy levels and hormones affect their performance? In elite female athletes, restricting calories or overtraining can silently impact both their body and their results. Small changes in energy intake or hormone levels may have big consequences for performance in competitive sports.
Purpose
This study aimed to examine how ovarian suppression and energy deficiency affect swimming performance in junior elite female swimmers. Specifically, researchers looked at how hormones like progesterone, estradiol, TT3, and IGF-1, along with energy intake and availability, influence 400-meter swim speed over a 12-week competitive season.
Methods
Ten junior elite female swimmers, aged 15–17, were monitored throughout a 12-week season. Menstrual status was tracked using circulating estradiol (E2) and progesterone (P4), categorizing athletes as either cyclic (CYC) or ovarian-suppressed (OVS). Every two weeks, researchers measured metabolic hormones, energy intake, energy availability, and swimming performance to evaluate how these factors changed over the season.
Vocabulary
Progesterone (P4): Progesterone is a steroid hormone produced mainly by the ovaries after ovulation. It helps regulate the menstrual cycle and prepares the uterus for pregnancy. Suppressed progesterone can also signal disrupted reproductive and metabolic function, which may affect overall health and performance.
Estradiol (E2): Estradiol is the primary form of estrogen in young women, produced by the ovaries. It regulates the menstrual cycle, maintains bone health, and supports cardiovascular and reproductive systems.
Total Triiodothyronine (TT3): TT3 is a thyroid hormone that plays a central role in regulating metabolism. In energy-deficient athletes, TT3 levels can drop as the body “conserves” energy. Lower TT3 is linked to slower metabolism and reduced ability to benefit fully from training, leading to poorer performance.
Insulin-like Growth Factor 1 (IGF-1): It promotes muscle growth, tissue repair, and overall growth during adolescence.
Results
Hormones: OVS swimmers had significantly lower P4 and E2 levels across the season, confirming ovarian suppression.
Metabolic Markers: TT3 and IGF-1 were lower in OVS swimmers compared to CYC (TT3: 1.4 vs. 1.6 nmol·L; IGF-1: 214 vs. 243 μg·mL).
Energy: Energy intake and energy availability were significantly lower in OVS swimmers.
Performance: OVS swimmers’ 400-meter swim velocity dropped by 9.8%, while CYC swimmers improved by 8.2% by week 12.
Conclusions
This study shows a strong link between hormone levels, energy status, and performance. Ovarian suppression combined with low energy availability and reduced metabolic hormones like TT3 is associated with poorer sport performance. For young elite athletes, this highlights the importance of careful dietary and training periodization to optimize energy intake, support hormonal health, and maximize performance outcomes.
Citation
Vanheest JL, Rodgers CD, Mahoney CE, De Souza MJ. Ovarian suppression impairs sport performance in junior elite female swimmers. Med Sci Sports Exerc. 2014 Jan;46(1):156-66. doi: 10.1249/MSS.0b013e3182a32b72. PMID: 23846160.