Strenuous Training Research Articles

Whole-Body Cryotherapy: Potential to Enhance Athlete Preparation for Competition?

The final hours of preparation before competition are important for performance. Recovery, preparation and warm up protocols are evolving continuously and include passive and active modalities often developed by “trial and error” approaches. Passive modalities, such as whole-body cryotherapy (WBC), have the potential to enhance both recovery and preparation. Whole-body cryotherapy has generally been used within a recovery setting after competition or strenuous training for athletes, and in clinical settings for the general population. However, the acute hormonal, anti-inflammatory, perceptual and psychological responses yielded by a single, or repeated, bouts of WBC indicate that this practice could enhance an athlete’s competition readiness when used alongside traditional elements of active warm-ups in the hours before competition in addition to aiding recovery in the hours after. Here we summarize and evaluate the acute effects of WBC exposures on physiological, performance and perceptual responses, and examine the likelihood these responses could theoretically translate into enhanced athletic performance. The potential to enhance an athlete’s performance using acute passive WBC exposure is a novel intervention that requires further investigation.

Effects of almond, dried grape and dried cranberry consumption on endurance exercise performance, recovery and psychomotor speed: protocol of a randomised controlled trial

BackgroundFoods rich in nutrients, such as nitrate, nitrite, L-arginine and polyphenols, can promote the synthesis of nitric oxide (NO), which may induce ergogenic effects on endurance exercise performance. Thus, consuming...

The Relationship between Test Anxiety and Academic Performance among Undergraduate Medical Students: A Cross-sectional Study

Undergraduate medical education comprises strenuous study and training for five and half years. Mental health of medical students remains affected throughout this period. The present study was done to assess the test anxiety in the undergraduate medical students and to find out the relationship between the test anxiety and academic performance in the students. This cross-sectional study was conducted in a rural BPS Government Medical College For Women, Khanpur Kalan, Sonepat. The study population included all the undergraduate medical students enrolled from 2013 to 2017. Data pertaining to various socio-demographic characteristics were obtained by interview technique using a pre-designed, pre-tested questionnaire ensuring privacy and confidentiality and reviewing academic records. Nist and Diehl test anxiety questionnaire was used to determine the anxiety score of students. Statistical analyses were carried out with R v 3.5.1. A total of 240 students participated in the study. More than one quarter (26.3%) of the students did not suffer from test anxiety, 62.9% students exhibited healthy test anxiety and 10.8% of the students experienced unhealthy test anxiety. In relation to academic performance of the respondents, 4 (12.5%), 47 (24.9%) and 12 (63.2%) of respondents who performed fair, good and excellent respectively had no anxiety level as against those who had healthy anxiety and unhealthy anxiety level and these differences were statistically significant. In conclusion, the text anxiety is significantly associated with academic performance. These findings suggest the need of healthcare provision to prevent unhealthy test anxiety among medical students, as it decreases the academic performance.

Testosterone Status Following Short-term, Severe Negative Energy Balance Predicts Fat-free Mass Loss in U.S. Marines

Male US military personnel exposed to periods of severe negative energy balance often experience marked reductions in circulating total testosterone, and it is not uncommon for concentrations to fall below normal levels (<300 ng/dL). However, testosterone fluctuations following severe negative energy balance are variable, and little is known about the metabolic and physiological differences between males who experience low testosterone (LT) and those who maintain normal testosterone (NT). PURPOSE: To determine metabolic and physiological differences between males with LT versus those with NT following 8 d of strenuous military training. METHODS: Male US Marines (n = 68) were dichotomized based on testosterone concentration (< or ≥ 300 ng/dL) following 8 d of severe negative energy balance incurred during military training. Body composition (DEXA) and whole-body protein turnover (15N alanine) were measured and blood and urine samples collected before (PRE) and after (POST) training. Linear mixed models were used to assess the effects of testosterone status, time, and their interaction on outcomes. RESULTS: Testosterone concentrations decreased PRE (505 ± 135 ng/dL) to POST (284 ± 115 ng/dL, P < 0.01). When volunteers were dichotomized by POST testosterone status (NT, n = 24: 407 ± 97 vs. LT, n = 44: 217 ± 52 ng/dL, P < 0.01), PRE BMI, total fat mass, and testosterone were greater in NT compared to LT (P < 0.05). LT lost more fat-free mass (FFM, -3.4 ± 1.3 kg) and less fat mass (-2.4 ± 1.2 kg) compared to NT (-2.4 ± 2.0 and -3.2 ± 1.6 kg, respectively; P-interaction < 0.03). Insulin (+5.55 ± 9.35 μU/mL) and norepinephrine (+0.23 ± 0.29 ng/mL) increased from PRE to POST in LT, whereas no changes occurred in NT (+1.03 ± 3.75 μU/mL and +0.04 ± 0.30 ng/mL, respectively), resulting in significant differences between groups (P-interaction < 0.02). Independent of time, LT had greater whole-body protein synthesis, breakdown, and flux (P-status < 0.01), but not net balance (P-status = 0.2), compared to NT. CONCLUSION: Military personnel susceptible to operational stress-induced LT may be predisposed to greater FFM loss during periods of negative energy balance incurred during short-term, strenuous military training. Supported by US Army Medical Research and Materiel Command; authors’ views not official US Army or DoD policy.

Ketone ester supplementation blunts overreaching symptoms during endurance training overload.

Key points Overload training is required for sustained performance gain in athletes (functional overreaching). However, excess overload may result in a catabolic state which causes performance decrements for weeks (non‐functional overreaching) up to months (overtraining).Blood ketone bodies can attenuate training‐ or fasting‐induced catabolic events. Therefore, we investigated whether increasing blood ketone levels by oral ketone ester (KE) intake can protect against endurance training‐induced overreaching.We show for the first time that KE intake following exercise markedly blunts the development of physiological symptoms indicating overreaching, and at the same time significantly enhances endurance exercise performance.We provide preliminary data to indicate that growth differentiation factor 15 (GDF15) may be a relevant hormonal marker to diagnose the development of overtraining.Collectively, our data indicate that ketone ester intake is a potent nutritional strategy to prevent the development of non‐functional overreaching and to stimulate endurance exercise performance. It is well known that elevated blood ketones attenuate net muscle protein breakdown, as well as negate catabolic events, during energy deficit. Therefore, we hypothesized that oral ketones can blunt endurance training‐induced overreaching. Fit male subjects participated in two daily training sessions (3 weeks, 6 days/week) while receiving either a ketone ester (KE, n = 9) or a control drink (CON, n = 9) following each session. Sustainable training load in week 3 as well as power output in the final 30 min of a 2‐h standardized endurance session were 15% higher in KE than in CON (both P < 0.05). KE inhibited the training‐induced increase in nocturnal adrenaline (P < 0.01) and noradrenaline (P < 0.01) excretion, as well as blunted the decrease in resting (CON: −6 ± 2 bpm; KE: +2 ± 3 bpm, P < 0.05), submaximal (CON: −15 ± 3 bpm; KE: −7 ± 2 bpm, P < 0.05) and maximal (CON: −17 ± 2 bpm; KE: −10 ± 2 bpm, P < 0.01) heart rate. Energy balance during the training period spontaneously turned negative in CON (−2135 kJ/day), but not in KE (+198 kJ/day). The training consistently increased growth differentiation factor 15 (GDF15), but ∼2‐fold more in CON than in KE (P < 0.05). In addition, delta GDF15 correlated with the training‐induced drop in maximal heart rate (r = 0.60, P < 0.001) and decrease in osteocalcin (r = 0.61, P < 0.01). Other measurements such as blood ACTH, cortisol, IL‐6, leptin, ghrelin and lymphocyte count, and muscle glycogen content did not differentiate KE from CON. In conclusion, KE during strenuous endurance training attenuates the development of overreaching. We also identify GDF15 as a possible marker of overtraining.

Can strenuous exercise harm the heart? Insights from a study of cardiovascular neural regulation in amateur triathletes.

Regular exercise is recommended to improve the cardiovascular risk profile. However, there is growing evidence that extreme volumes and intensity of long-term exertion may increase the risk of acute cardiac events. The aim of this study is to investigate the after-effects of regular, strenuous physical training on the cardiovascular neural regulation in a group of amateur triathletes compared to age-matched sedentary controls. We enrolled 11 non-elite triathletes (4 women, age 24±4 years), who had refrained from exercise for 72 hours, and 11 age-matched healthy non-athletes (3 women, age 25±2 years). Comprehensive echocardiographic and cardiopulmonary exercise tests were performed at baseline. Electrocardiogram, non-invasive blood pressure, respiratory activity, and muscle sympathetic nerve activity (MSNA) were continuously recorded in a supine position (REST) and during an incremental 15° step-wise head-up tilt test up to 75° (TILT). Blood samples were collected for determination of stress mediators. Autoregressive spectral analysis provided the indices of the cardiac sympathetic (LFRR) and vagal (HFRR) activity, the vascular sympathetic control (LFSAP), and the cardiac sympatho-vagal modulation (LF/HF). Compared to controls, triathletes were characterized by greater LFRR, LF/HF ratio, LFSAP, MSNA, and lower HFRR at REST and during TILT, i.e. greater overall cardiovascular sympathetic modulation together with lower cardiac vagal activity. Cortisol and adrenocorticotropic hormone concentrations were also higher in triathletes. In conclusion, triathletes were characterized by signs of sustained cardiovascular sympathetic overactivity. This might represent a risk factor for future cardiovascular events, given the known association between chronic excessive sympathetic activity and increased cardiovascular risk.

Defining Exposures in Professional Football: Professional American-Style Football Players as an Occupational Cohort.

Studies of professional American football players have shown that football-related activities lead to acute injuries and may have long-term adverse health outcomes including osteoarthritis, neurocognitive impairment, and cardiovascular disease. However, the full complement of what constitutes professional football exposure has yet to be effectively articulated. Most likely, professional football exposure encompasses a multifaceted array of experiences including head impacts and joint stresses, long-term pain medication use, dietary restrictions, and strenuous training regimens. To study the health of professional American football players, characterizing the group as an occupational cohort and taking advantage of methods established within the discipline of occupational epidemiology may be beneficial. We conducted a narrative review of existing football research, occupational epidemiological methods papers, and occupational medicine studies. Here we describe the traditional occupational epidemiological approach to assessing exposure in a novel cohort and show how this framework could be implemented in studies of professional football players. In addition, we identify the specific challenges associated with studying an elite athletic occupational group, including the healthy worker effect and other types of selection and information biases, and explore these in the context of existing studies of football-related health. The application of well-established occupational epidemiological methods to professional football players may yield new insights into the effects of playing exposure and may provide opportunities for interventions to reduce harm.

The relationship between vitamin D status and depression in a tactical athlete population

BackgroundStressors inherent to the military, such as combat exposure, separation from family, and strenuous training, collectively contribute to compromised psychological resilience and greatly impact military performance.MethodsThis retrospective review of records was conducted to determine whether vitamin D status was associated with diagnoses of depression and if diagnoses differed by geographic location.ResultsDepression (defined using diagnostic codes) was more prevalent in individuals who were diagnosed with vitamin D deficiency (20.4%) than in individuals who were not (4.2%). After adjustment, vitamin D deficient diagnoses remained significantly associated with depression diagnoses (OR = 1.22; 95% CI, 1.11–1.33, p < 0.001). Furthermore, vitamin D deficient diagnoses were strongly associated with geographic latitude (r2 = 0.92, p = 0.002).ConclusionThese results suggest that service members stationed at installations located at northerly latitudes may be at increased risk for vitamin D deficiency. Furthermore, vitamin D deficient service members may be at higher risk for diagnosis of depression. As a number of military service members avoid reporting symptoms or seeking treatment, vitamin D status may be a useful screening tool to identify service members at risk for depression.

Investigation into the thermal comfort of university students conducting outdoor training

Heat stress negatively influences human health and performance, leading to lower efficiency in daily activities. In particular, strenuous training in outdoor hot environment conditions increases the potential for developing heat illness, such as heat cramps, heat exhaustion, and heat stroke. Few investigations have been conducted on heat stress during high-intensity outdoor training. The present study aims to summarize the evidence on the relations between high-intensity outdoor training and heat illness and between heat indices, including Wet Bulb Globe Temperature (WBGT), Physiological Equivalent Temperature (PET) and Universal Thermal Climate Temperature (UTCI), and environmental parameters. In this investigation, fresh students were invited as volunteers to answer the questionnaire about their heat perception with microclimate measurements when they had a rest in a session of outdoor training. The results showed that some students had heat syncope and more than 30% suffered from “profuse sweating.” The effect of air temperature on thermal comfort was most significant. The stress categories of WBGT, PET, and UTCI need to be modified for freshmen outdoor training to avoid overexposure in a hot outdoor environment.

The effects of curcumin supplementation on oxidative stress inducedduring strenuous endurance training on the kidney and lung tissues

The effects of curcumin supplementation on oxidative stress inducedduring strenuous endurance training on the kidney and lung tissues

Rhodiola rosea, a protective antioxidant for intense physical exercise: An in vitro study

In physiological conditions, the response to oxidative stress induced by strenuous physical training, is not always efficient. Furthermore, a weak muscle fiber antioxidant system can contribute to muscle wasting during ageing and pathological conditions. Natural antioxidant supplements could counteract the effects of oxidative stress. An in vitro model of exercise allowed us to mimic intense or moderate exercise by electrically stimulating cultured mouse myotubes with high- and/or low-frequency pulses; the resulting ROS production was then monitored. The herbal supplement Rhodiola rosea aqueous extract was characterized in terms of its polyphenol content and used to test for antioxidant activity against ROS, produced during muscle contraction. Our results showed that Rhodiola rosea extract reduced the oxidative stress produced by muscle contraction and brought values of ROS production back to physiological levels. We suggest that Rhodiola rosea root extract could exert a protective antioxidant role during intense physical exercise.

Effects of Riot Control Training on Systemic Microvascular Reactivity and Capillary Density

The main aim of the present study is to evaluate the effects of strenuous exercise, related to special military training for riot control, on systemic microvascular endothelial function and skin capillary density. Endothelium-dependent microvascular reactivity was evaluated in the forearm skin of healthy military trainees (age 23.4 ± 2.3 yr; n = 15) using laser speckle contrast imaging coupled with cutaneous acetylcholine (ACh) iontophoresis and post-occlusive reactive hyperemia (PORH). Functional capillary density was assessed using high-resolution, intra-vital color microscopy in the dorsum of the middle phalanx. Capillary recruitment (capillary reserve) was evaluated using PORH. Microcirculatory tests were performed before and after a 5-wk special military training for riot control. Microvascular endothelium-dependent vasodilatory responses were markedly and significantly reduced after training, compared with values obtained before training. The peak values of microvascular conductance obtained during iontophoresis of ACh or PORH before training (0.84 ± 0.22 and 0.94 ± 0.72 APU/mmHg, respectively) were markedly reduced after training (0.47 ± 0.11 and 0.71 ± 0.14 APU/mmHg; p < 0.0001 and p = 0.0037, respectively). Endothelium-dependent capillary recruitment was significantly reduced after training (before 101 ± 9 and after 95 ± 8 capillaries/mm2; p = 0.0007). The present study showed that a 5-wk strenuous military training, performed in unfavorable climatic conditions, induces marked systemic microvascular dysfunction, mainly characterized by reduced endothelium-dependent microvascular vasodilation and blunted capillary recruitment.

Prevalence of Iron Deficiency and Iron Deficiency Anemia in Strenuously Training Male Army Recruits

Objectives: The objectives of our study were to determine the effect of strenuous physical training on the prevalence of iron deficiency anemia (IDA), iron deficiency (ID) with normal hemoglobin (Hb), and anemia without ID. Methods: Our study was a prospective observational study. We followed 115 healthy male recruits in the Israel Defense Forces elite units during 15 months of training. Blood samples were collected at recruitment and at 6-, 9- and 15-month follow-ups. Results: Upon recruitment, anemia (Hb <14 g/dL), ID, and ID anemia (IDA) were diagnosed in 28, 31, and 9% of individuals, respectively. Sixty-three subjects (54%) were followed for 6 months; 9 of them (14%) developed new-onset IDA. Among them, the prevalence of anemia rose from 19 to 52%, and ID from 33 to 35%. At the 15-month follow-up, 29% had developed new-onset IDA and 65% showed evidence of ID. Conclusion: We report a high prevalence of anemia, ID, and IDA among young healthy males participating in prolonged strenuous training programs. These findings can be partly explained by the physiological changes associated with strenuous physical activity. Further investigations aiming to develop specific diagnostic guidelines for this unique population are warranted.

Nandrolone combined with strenuous resistance training reduces vascular nitric oxide bioavailability and impairs endothelium-dependent vasodilation

Anabolic Androgenic Steroids (AASs) misuse has increased among adolescents and recreational athletes due to their potential effects on muscle hypertrophy. On the other hand, AAS might induce alterations on cardiovascular system, although some controversies regarding AAS on vascular properties remain unknown. To address this question, we aimed to investigate the effects of high doses of nandrolone combined with strenuous resistance training (RT) on function and structure of thoracic aorta. Rats were randomized into four groups: non-trained vehicle (NTV), trained vehicle (TV), non-trained nandrolone (NTN), and trained nandrolone (TN), and submitted to 6 weeks of treatment with nandrolone (5 mg/kg, twice a week) and/or resistance training. In vitro response of thoracic aorta to acetylcholine (ACh) was analyzed. Vascular nitric oxide (NO) and reactive oxygen species (ROS) synthesis were evaluated using 4,5-diaminofluorescein diacetate (DAF-2) and hydroethidine fluorescent techniques, respectively. Thoracic aorta was processed for microscopy analyses and tunica media thickness was measured. ACh-mediated relaxation response was impaired in endothelium intact aortic rings isolated from trained rats (TV and TN) as compared with their matched non-trained groups. TN rats showed reduced ACh-mediated vasodilatation than NTN rats. NO production and bioavailability decreased in thoracic aorta of nandrolone-treated rats in relation to their matched non-trained group (NTN vs. NTV; TN vs. TV). ROS production and tunica media thickness were increased in TN rats when compared with TV rats. These findings indicate that high doses of nandrolone combined with strenuous RT affect NO bioavailability and might induce endothelial dysfunction and arterial morphological alterations.

Anthropometric predispositions for swimming from the perspective of biomechanics.

Early identification of anthropological potential in swimmers is considered important to the recruitment and selection of children and adolescents to perform extensive and strenuous training. The aim of the research was a comparative analysis of the anthropometric parameters and indicators of adult, elite swimmers with people who had never trained for swimming. It was assumed that the specific characteristics of the swimmers' somatic composition referred to the laws of swimming biomechanics. Anthropometric measurements were taken in a group of elite male swimmers (N = 28), aged 17-24. The same set of measurements was taken in a homogeneous control group of students of physical education. An anthropometric profile significantly differentiating swimmers from the control group was constructed. Next, a linear forward stepwise discriminant analysis was conducted to investigate which indices can be used to distinguish the two groups. It seems significant that a specific somatic composition trait of swimmers in the form of a relatively long shank was observed, which had not been observed in earlier studies. Additionally, indices of relatively slim hand dimension, and indices describing a "reversed triangle" shape of trunk, were the most powerful discrimination variables between the two examined groups. The results obtained cannot be generalised to the entire population of swimmers, however referring them to the laws of biomechanics of swimming allows for the continuation of research into identifying the prognostic traits desirable for success among young swimmers.

PERSONALIZED EXERCISE TRAINING PROGRAM AS A COUNTERMEASURE TO ORTHOSTATIC INTOLERANCE AFTER SPACE FLIGHTS.

PERSONALIZED EXERCISE TRAINING PROGRAM AS A COUNTERMEASURE TO ORTHOSTATIC INTOLERANCE AFTER SPACE FLIGHTS.

Effectiveness of air pulsed cryotherapy on delayed onset muscle soreness of elbow flexors following eccentric exercise

Cryotherapy is widely used in sports to facilitate recovery from exercise-induced muscle damage that often results from strenuous training and/or competition. However, a paucity of evidence exists on the therapeutic values of repeated air pulsed cryotherapy (CRYO) application to suggest its usefulness to clinicians, coaches, sports scientists and athletes in the field of sports and rehabilitation. Aim: This study investigates the effectiveness of CRYO on the recovery from delayed onset of muscle soreness (DOMS) induced by eccentric exercise. Materials and methods: Thirty-two participants (21.31±1.03 years; height 1.72±0.05 m; BMI 22.15±1.69 kg.cm-2) were equally randomized into CRYO group and control group (CONT). DOMS was induced by eccentric contractions of elbow flexors. Visual analogue scale score (VAS), mid arm circumference (MAC), pressure pain threshold (PPT), range of motion of active elbow flexion (ROM-AF), passive elbow flexion (ROM-PF), active elbow extension (ROM-AE), passive elbow extension (ROM-PE) and isometric peak torque of elbow flexors (IPT) were measured at pre-exercise (PRE), immediately, 1, 2, 3, 4, and 7 days post exercise. Results and discussion: There were significant interactions effect (group X time) with (P<0.05) for VAS, MAC, PPT, ROM-PF, ROM-AE, and ROMPE. Additionally, all outcome measures (except for ROM-AF and IPT) demonstrated a significant improvement (P<0.05) in DOMS recovery in the CRYO group compared to CONT group. Conclusion: A 20 minutes (4 session X5 minutes) session for 5 consecutive days of repeated air pulsed cryotherapy has beneficial effects on the recovery of DOMS on elbow flexors from eccentric exercise.

INJURIES IN PROFESSIONAL DANCERS: A SYSTEMATIC REVIEW

ABSTRACT Movement is a fundamental element of dance, and the dancer’s body is the raw material through which the art of dance is expressed; for this, it demands the utmost discipline in the pursuit of technical and artistic excellence. To meet the professional demands, dancers are subjected to strenuous training routines, which can lead to the development of injuries in this environment. The objective was to examine the etiology, main affected segments, prevalence, and instruments used to evaluate the lesions in studies with professional dancers and/or in comparison with similar populations. We selected articles published in the last decade in the databases BIREME, LILACS, MEDLINE EBSCO, WEB OF SCIENCE, SCOPUS (Elsevier), and PubMed, with cross-sectional, observational cohort and case control design published in Portuguese, English, or Spanish. Systematic reviews, case studies, dissertations, theses, book chapters, cross-referenced articles, and studies published outside of the last decade were not included. The search used combinations of the terms “dancing* and athletic injuries* and musculoskeletal* and pain*”. A principal investigator and two reviewers conducted the survey and analyzed all the potentially relevant articles, initially by the abstract and title. Twelve articles were included, with 1,149 participants (965 professional dancers of classical ballet, modern dance, contemporary dance, and breakdance, 104 amateur dancers, and 80 elite athletes). Nine studies found simultaneous lesions with emphasis on the foot and ankle (n=4), upper and lower limbs lesions (n=4) and lower and upper limb joints (n=1). Other studies have found lesions in the anterior cruciate ligament (n=3). There was no agreement regarding the instruments for detecting lesions in professional, pre-professional, and amateur dancers. There was a prevalence of studies aimed at classical ballet modality, evidencing a higher frequency of lower limb involvement in professional dancers.

Exercise and Competitive Sport: Physiology, Adaptations, and Uncertain Long-Term Risks.

The benefits of regular and moderate exercise training on cardiovascular outcomes have been well established. In addition, strenuous exercise training leads to corollary cardiac structural and functional adaptations that are sport-specific and facilitate athletic performance. In this review, the normal physiologic and hemodynamic changes that occur during exercise and the subsequent differential exercise-induced cardiac remodeling patterns that develop will be discussed. Paradoxically, recent data have raised concern about the long-term impact of higher doses of physical activity and exercise on mortality and cardiovascular health outcomes. We will discuss important aspects of these controversial data and review the supporting evidence as well as the limitations of prior research. Specifically, we will address the association between high levels of exercise and relative reductions in overall mortality, increased risk of atrial fibrillation, arrhythmogenic cardiac remodeling, and accelerated coronary artery calcifications. For the practitioner, this review aims to detail these contemporary sports cardiology controversies and highlights the critical need to incorporate shared decision making with the athlete in dealing with the uncertainties that exist. Finally, we will discuss key "athlete-specific" variables that should be considered in the design of future important research in this arena.

Military training elicits marked increases in plasma metabolomic signatures of energy metabolism, lipolysis, fatty acid oxidation, and ketogenesis.

Military training studies provide unique insight into metabolic responses to extreme physiologic stress induced by multiple stressor environments, and the impacts of nutrition in mediating these responses. Advances in metabolomics have provided new approaches for extending current understanding of factors modulating dynamic metabolic responses in these environments. In this study, whole‐body metabolic responses to strenuous military training were explored in relation to energy balance and macronutrient intake by performing nontargeted global metabolite profiling on plasma collected from 25 male soldiers before and after completing a 4‐day, 51‐km cross‐country ski march that produced high total daily energy expenditures (25.4 MJ/day [SD 2.3]) and severe energy deficits (13.6 MJ/day [SD 2.5]). Of 737 identified metabolites, 478 changed during the training. Increases in 88% of the free fatty acids and 91% of the acylcarnitines, and decreases in 88% of the mono‐ and diacylglycerols detected within lipid metabolism pathways were observed. Smaller increases in 75% of the tricarboxylic acid cycle intermediates, and 50% of the branched‐chain amino acid metabolites detected were also observed. Changes in multiple metabolites related to lipid metabolism were correlated with body mass loss and energy balance, but not with energy and macronutrient intakes or energy expenditure. These findings are consistent with an increase in energy metabolism, lipolysis, fatty acid oxidation, ketogenesis, and branched‐chain amino acid catabolism during strenuous military training. The magnitude of the energy deficit induced by undereating relative to high energy expenditure, rather than macronutrient intake, appeared to drive these changes, particularly within lipid metabolism pathways.