Kathryn E Ackerman

Partners HealthCare

Up to 40% of elite athletes experience bone stress injuries (BSIs), with 20-30% facing reinjury. Early identification of runners at high risk of subsequent BSI could improve prevention strategies. However, the complex etiology and multifactorial risk factors of BSIs makes identifying predictive risk factors challenging. In a study of 30 female recr...

Purpose To examine sex-based differences in substrate oxidation, postprandial metabolism, and performance in response to 24-hour manipulations in energy availability (EA), induced by manipulations to energy intake (EI) or exercise energy expenditure (EEE). Methods In a Latin Square design, 20 endurance athletes (10 females using monophasic oral co...

Objective To determine the association between survey-based self-reported problematic low energy availability indicators (LEA-I) and race performance and intra-event medical encounters during the Boston Marathon. Methods 1030 runners who were registered for the 2022 Boston Marathon completed an electronic survey (1–4 weeks pre-race) assessing LEA-...

Purpose: To examine the relationship between menstrual cycle (MC) phase-dependent fluctuations of estrogen and progesterone and virtual cycling race performance, with a secondary aim of correlating perceived MC-related symptoms with performance. Methods: In a novel observational study design, thirty-seven female cyclists/triathletes not using any h...

Objectives To determine the association between surrogates of low energy availability (EA) and proposed health and performance outcomes of Relative Energy Deficiency in Sport (REDs) in a clinical sample of adolescent and young adult male athletes. Methods Male athletes ages 15–30 years presenting to a sports medicine clinic at two tertiary care ce...

Introduction Few studies have assessed athletic identity levels in young patients. This study examined athletic identity in adolescents and explored associations between athletic identity, patterns of sport participation, and coping skills. Methods Patients aged 12 to 18 years who received sports medicine care completed a one-time, voluntary, anon...

Purpose To investigate the effects of acute diet and exercise manipulation on resting metabolic rate (RMR) measurement variability and dual energy x-ray absorptiometry (DXA) body composition estimates. Methods 10 male and 10 female endurance athletes (12 cyclists, 5 triathletes, 4 runners) of Tier 2 (n = 18) to Tier 3 (n = 2) calibre underwent fiv...

Purpose: To investigate the temporal effects of ~1,800 m altitude exposure and energy availability (EA) manipulation on resting metabolic rate (RMR). Methods: Twenty elite female race walkers underwent a 3-week training camp at an altitude of ~1,800 m. During the first two weeks, athletes consumed a high EA (HEA) diet of 45 kcal·kg fat free mass...

Objective This cross-sectional retrospective and prospective study implemented the 2023 International Olympic Committee Relative Energy Deficiency in Sport (REDs) Clinical Assessment Tool version 2 (CAT2) to determine the current severity of REDs (primary outcome) and future risk of bone stress injuries (BSI, exploratory outcome) in elite athletes....

Low energy availability, particularly when problematic (i.e., prolonged and/or severe), has numerous negative consequences for health and sports performance as characterized in relative energy deficiency in sport. These consequences may be driven by disturbances in endocrine function, although scientific evidence clearly linking endocrine dysfuncti...

Objectives To co-construct a sports medicine and exercise science research and translational agenda with Team USA elite female athletes serving as the experts on their health, performance and well-being. Methods 40 Team USA female athletes across sports disciplines participated in an online, anonymous, modified Delphi survey by ranking topics on a...

We examined performance across one menstrual cycle (MC) and 3 weeks of hormonal contraceptives (HC) use to identify whether known fluctuations in estrogen and progesterone/progestin are associated with functional performance changes. National Rugby League Indigenous Women's Academy athletes [n = 11 naturally menstruating (NM), n = 13 using HC] comp...

Background Bone stress injury (BSI) is a common overuse injury in active women. BSIs can be classified as high-risk (pelvis, sacrum, and femoral neck) or low-risk (tibia, fibula, and metatarsals). Risk factors for BSI include low energy availability, menstrual dysfunction, and poor bone health. Higher vertical load rates during running have been ob...

The cyclical changes in sex hormones across the menstrual cycle (MC) are associated with various biological changes that may alter resting metabolic rate (RMR) and body composition estimates. Hormonal contraceptive (HC) use must also be considered given their impact on endogenous sex hormone concentrations and synchronous exogenous profiles. The pu...

Background The impact of the menstrual cycle on performance is being increasingly recognised as an important consideration for female athletes. Objective To explore experiences and perceptions of the impact of the menstrual cycle on performance in female rowers. Design An online mixed methods approach. Setting An anonymous, 47-item questionnaire...

Purpose To describe the implementation of a novel research protocol for conducting research with highly-trained female athletes, including characterising menstrual cycle (MC) function, hormonal profiles and symptoms of the participating athletes. Methods Twenty-four Australian First Nation female Rugby League athletes completed this study, which i...

Background Female Athlete Triad (Triad) and Relative Energy Deficiency in Sport (REDs) describe potential health and performance consequences of low energy availability. Objective We surveyed female cross-country athletes to assess differences in educational impact scores (knowledge score * confidence score factor, EIS) of Triad and REDs. Associat...

Purpose: Over a 10-year time frame, this study aimed to evaluate diagnosis, treatment, and referral trends for adolescent runners seeking care for running-related injuries (RRIs) at a clinic that specializes in running medicine. Methods: This study was a retrospective chart review of 392 adolescent runners (2,326 encounters) who sought care for...

The idiom ‘more high-quality research is needed’ has become the slogan for sport and exercise physiology-based research in female athletes. However, in most instances, it is challenging to address this gap of high-quality research in elite female athletes at a single study site due to challenges in recruiting enough participants with numerous menst...

Sufficient high-quality studies in sport science using women as participants are lacking, meaning that our knowledge and understanding of female athletes in relation to their ovarian hormone profiles is limited. Consortia can be used to pool talent, expertise and data, thus accelerating our learning on a given topic and reducing research waste thro...

The 2023 International Olympic Committee (IOC) consensus statement on Relative Energy Deficiency in Sport (REDs) notes that exposure to low energy availability (LEA) exists on a continuum between adaptable and problematic LEA, with a range of potential effects on both health and performance. However, there is variability in the outcomes of LEA expo...

Relative Energy Deficiency in Sport (REDs) has various different risk factors, numerous signs and symptoms and is heavily influenced by one’s environment. Accordingly, there is no singular validated diagnostic test. This 2023 International Olympic Committee’s REDs Clinical Assessment Tool—V.2 (IOC REDs CAT2) implements a three-step process of: (1)...

Relative Energy Deficiency in Sport (REDs) was first introduced in 2014 by the International Olympic Committee’s expert writing panel, identifying a syndrome of deleterious health and performance outcomes experienced by female and male athletes exposed to low energy availability (LEA; inadequate energy intake in relation to exercise energy expendit...

In the past decade, the study of relationships among nutrition, exercise and the effects on health and athletic performance, has substantially increased. The 2014 introduction of Relative Energy Deficiency in Sport (REDs) prompted sports scientists and clinicians to investigate these relationships in more populations and with more outcomes than had...

Relative Energy Deficiency in Sport (REDs) is common among female and male athletes representing various sports at different performance levels, and the underlying cause is problematic low energy availability (LEA). It is essential to prevent problematic LEA to decrease the risk of serious health and performance consequences. This narrative review...

Objective: To evaluate clinic visits and running-related injury (RRI) characteristics among child and adolescent runners seeking care at an outpatient clinic over a 10-year time frame. Design: Retrospective chart review. Setting: Outpatient hospital-affiliated Injured Runners Clinic. Patients: Children and adolescent runners (6-17 years) wit...

Youth athletes have elevated energy needs to support training demands, growth, and development. These increased needs put them at risk for low energy availability (EA), which can lead to numerous unintended health and performance consequences. Adolescence is additionally a time of susceptibility to developing disordered eating (DE) or an eating dis...

The IOC made recommendations for recording and reporting epidemiological data on injuries and illness in sports in 2020, but with little, if any, focus on female athletes. Therefore, the aims of this supplement to the IOC consensus statement are to (i) propose a taxonomy for categorisation of female athlete health problems across the lifespan; (ii)...

The uptick in enthusiasm over the last decade surrounding sports and exercise science (SES) in females has yet to be reflected in the publication of high-quality research studies illustrating sound and applicable findings. As a result of the growing community of researchers and our global orientation toward evidence-based practice, the SES field mu...

Objective Studies in estrogen deficiency states such as primary ovarian insufficiency and Turner syndrome suggest that estrogen status may be an important modulator of mood and emotions. In this study we compared depressive and anxiety symptoms between adolescent and young adult female oligo-amenorrheic athletes (AA) and eumenorrheic females (EM),...

The aim of this audit was to assess the representation of female athletes, dietary control methods, and gold standard female methodology that underpins the current guidelines for chronic carbohydrate (CHO) intake strategies for athlete daily training diets. Using a standardized audit, 281 studies were identified that examined high versus moderate C...

Context: Female athletes, particularly runners, with insufficient caloric intake for their energy expenditure (low energy availability or relative energy deficiency) are at risk for impaired skeletal integrity. Data are lacking in male runners. Objective: To determine whether male runners at risk for energy deficit have impaired bone mineral den...

Objective Bone stress injuries (BSIs) are classified in clinical practice as being at low- or high-risk for complication based on the injury location. However, this dichotomous approach has not been sufficiently validated. The purpose of this systematic review was to examine the prognostic role of injury location on return-to-sport (RTS) and treatm...

Purpose: The aim of this audit was to assess the representation of female athletes within the literature that has led to current guidelines for carbohydrate (CHO) intake in the acute periods surrounding exercise and the quality of this research. Methods: A standardized audit was conducted of research assessing CHO loading protocols, CHO mouth ri...

Micronutrient deficiencies and sub-optimal intakes among female athletes are a concern and are commonly prevented or treated with medical supplements. However, it is unclear how well women have been considered in the research underpinning current supplementation practices. We conducted an audit of the literature supporting the use of calcium, iron,...

Introduction: While an acute exercise session typically increases bone turnover markers (BTM), the impact of subsequent sessions and the interaction with pre-exercise calcium intake remains unclear despite the application to the 'real life' training of many competitive athletes. Methods: Using a randomized crossover design, elite male rowers (n...

Bone stress injuries are common in athletes, resulting in time lost from training and competition. Diets that are low in energy availability have been associated with increased circulating bone resorption and reduced bone formation markers, particularly in response to prolonged exercise. However, studies have not separated the effects of low energy...

Purpose: To determine whether 25-hydroxyvitamin D (25-OH D) levels are associated with bone outcomes in a multiracial cohort of young adults. Methods: This cross-sectional study included 165 participants (83 men, 82 women, 18-30y) who self-identified as Asian, Black, or White. We measured bone microarchitecture and strength of the distal radius...

Bone stress injuries (BSIs) are common among athletes and have high rates of recurrence. However, risk factors for multiple or recurrent BSIs remain understudied. Thus, we aimed to explore whether energy availability, menstrual function, measures of bone health, and a modified Female Athlete Triad Cumulative Risk Assessment (CRA) tool are associate...

Introduction: Exercise is an osteogenic stimulus that should increase bone mineral density (BMD) and protect against injury. However, some female athletes have lower BMD and increased bone stress injury (BSI) risk.. Impaired bone health seen in athletes may be explained by low energy availability as described by concepts of Relative Energy Deficie...

Bone stress injuries, including stress fractures, are overuse injuries that lead to substantial morbidity in active individuals. These injuries occur when excessive repetitive loads are introduced to a generally normal skeleton. Although the precise mechanisms for bone stress injuries are not completely understood, the prevailing theory is that an...

Although sports nutrition guidelines promote evidence-based practice, it is unclear whether women have been adequately included in the underpinning research. In view of the high usage rates of performance supplements by female athletes, we conducted a standardised audit of the literature supporting evidence-based products: β-alanine, caffeine, crea...

Female-specific research on sports science and sports medicine (SSSM) fails to mirror the increase in participation and popularity of women’s sport. Females have historically been excluded from SSSM research, particularly because their physiological intricacy necessitates more complex study designs, longer research times, and additional costs. Cons...

Tibial bone stress injuries (BSIs) are common injuries experienced by active adolescent athletes. The current literature lacks consensus of BSI nomenclature and appropriate use of imaging modalities. The purpose of this Current Concept Review is to identify existing classification of atraumatic tibial pain/BSI, propose unifying nomenclature, and re...

Purpose : Bone stress injuries (BSIs) are common in female runners, and recurrent BSI rates are high. Previous work suggests an association between higher impact loading during running and tibial BSI. However, it is unknown whether impact loading and fatigue related loading changes discriminate women with a history of multiple BSIs. This study comp...

A 16.5-year-old, distance runner, female gender-assigned at birth, who identifies as male, presented with menstrual dysfunction and impaired athletic performance. The cause of the menstrual dysfunction and decreased athletic performance was identified as inadequate energy availability, largely motivated by a desired avoidance of menstruation and fu...

Bone stress injury (BSI) of the tibia, a spectrum of impairments that include conditions commonly referred to as medial tibial stress syndrome (MTSS), tibial stress reaction, and tibial stress fracture, is relatively common in athletes of various ages and levels of competition. While simple rest from the offending activities remains the primary met...

Optimal nutrition is an important aspect of an athlete’s preparation to achieve optimal health and performance. While general concepts about micro- and macronutrients and timing of food and fluids are addressed in sports science, rarely are the specific effects of women’s physiology on energy and fluid needs highly considered in research or clinica...

Background The prevalence of dietary supplement intake among preadolescent endurance runners is currently unknown. Objective Our aim was to describe use of dietary supplements, higher-risk supplements, and sport foods among preadolescent endurance athletes and identify associated characteristics of dietary supplement users in this population. Des...

Introduction Bone stress injury (BSI) in youth runners are clinically important during times of skeletal growth and are not well studied. Objective Evaluate the prevalence, anatomical distribution, and factors associated with running-related BSI in boy and girl middle school runners. Design Retrospective cross-sectional study. Setting Online sur...

CONTEXT: Female endurance athletes exhibit an increased risk of Female Athlete Triad (Triad) and Relative Energy Deficiency in Sport (RED-S). Triad and REDS are conditions that explore the health and performance consequences of low energy availability (LEA). Few studies to date have assessed the knowledge that athletes, coaches, and athletic traine...

Objectives To determine whether serum 25-hydroxy vitamin D (25-OH D) levels are associated with bone microarchitecture and strength in a multi-racial cohort of young adults. We also determined if race and calcium intake modified these associations. Methods This cross-sectional study included 176 young adults who identified as Asian, Black, or Whit...

Introduction Understanding the prevalence and factors associated with running-related injuries in middle school runners may guide injury prevention. Objective To determine the prevalence of running-related injuries and describe factors related to a history of injury. Design Retrospective cross-sectional study. Setting Survey distributed online t...

The purpose of this case series was to evaluate the presence of low Energy Availability (EA) and its impact on components of Relative Energy Deficiency in Sport (RED-S) in a population of female collegiate runners. Seven female NCAA Division I athletes (age: 22.3 ± 1.5 yrs; height: 169.7 ± 5.7 cm; weight: 58.3 ± 4.1 kg) were tracked from August unt...

Background To determine if following specific diets was associated with reporting behaviors that are consistent with disordered eating compared to non-diet-adherent athletes. We hypothesized that athletes adhering to specific diets were more likely to report disordered eating than those not following a diet. Methods One thousand female athletes (1...

Bone stress injuries (BSIs) occur in up to 20% of runners and military recruits and those with a history of BSI have a 5-fold higher risk for a subsequent BSI. Yet, little is known about prior training, menstrual status and bone structure in runners who experience multiple BSIs. Purpose: To determine differences in health and physical activity hi...

Until recently, there has been less demand for and interest in female-specific sport and exercise science data. As a result, the vast majority of high-quality sport and exercise science data have been derived from studies with men as participants, which reduces the application of these data due to the known physiological differences between the sex...

The SARS CoV-2 virus (COVID-19) caused the whole sporting calendar to be paused. As we embark on the challenge of navigating through the return to play (RTP) process, there is a necessity to consider the needs of all athletes. This commentary specifically considers recommendations and requirements for the female athlete with a physiological emphasi...

Introduction Relative Energy Deficiency in Sport (RED-S) is a clinical syndrome that includes the many complex health and performance consequences of low energy availability (EA) in athletes, when there is insufficient caloric intake to meet exercise-related energy expenditure and to support basic physiologic functions. There is a high prevalence o...

Context Low energy availability causes disruption of hypothalamic gonadotropin-releasing hormone secretion leading to functional hypothalamic amenorrhea (FHA) and hypoestrogenism, which in turn contributes to decreased bone mineral density (BMD) and increased bone marrow adipose tissue (MAT). Transdermal estradiol administration in physiologic dose...