Outcomes of exertional rhabdomyolysis following high-intensity resistance training

Exertional rhabdomyolysis: an analysis of 321 hospitalised US military service members and its relationship with heat illness

INTRODUCTION

Exertional rhabdomyolysis is a syndrome of muscle breakdown following exercise. This study describes laboratory and demographic trends of service members hospitalised for exertional rhabdomyolysis and examines the relationships with heat illness.

METHODS

We queried the US Armed Forces Health Surveillance Center's Defence Medical Epidemiology Database for hospitalised cases of rhabdomyolysis associated with physical exertion from January 2010 July 2013. Descriptive statistics reported means and medians of initial, peak and minimal levels of creatine kinase (CK). Correlations explored the relationship between CK, creatinine, length of hospital stay (LOS) and demographic data.

RESULTS

We analysed 321 hospitalised cases of exertional rhabdomyolysis. 193 (60.1%) cases were associated with heat; 104 (32.4%) were not associated with heat; and 24 (7.5%) were classified as medical-associated exertional rhabdomyolysis. Initial, maximum and minimal CK levels were significantly lower in heat cases: CK=6528 U/L vs 19 247 U/L, p=0.001; 13 146 U/L vs 22 201 U/L, p=0.03; and 3618 U/L vs 10 321 U/L, p=0.023) respectively, compared with cases of rhabdomyolysis with exertion alone. Median LOS was 2 days (range=0-25). In the rhabdomyolysis with exertion alone group and the rhabdomyolysis with heat group, LOS was moderately correlated with maximal CK (Spearman's ρ=0.52, p<0.001, and Spearman ρ=0.38, p<0.001, respectively). There was no significant difference in median LOS between the rhabdomyolysis with exertion alone and rhabdomyolysis associated with heat groups (2 vs 2, p value=0.96).

CONCLUSION

Most hospitalisations for exertional rhabdomyolysis were associated with heat illness and presented with lower CK levels than cases without associated heat illness. These data add evidence that rhabdomyolysis with heat illness is a different entity than rhabdomyolysis with exertion alone. Differentiating exertional rhabdomyolysis with and without heat should inform future research on rhabdomyolysis prognosis and clinical management.

Avoidable healthcare costs of spinning-induced rhabdomyolysis: a case series

Spinning-induced rhabdomyolysis (SIR) is a well documented cause of exertional rhabdomyolysis. We aim to raise awareness and to call for preventive action towards avoidable healthcare costs associated with SIR. To this end, we describe three cases of SIR, associated healthcare costs and possible preventive strategies. We propose that community-based preventive measures should be considered in addressing the economic consequences of SIR.

Kidney physiology and pathophysiology during heat stress and the modification by exercise, dehydration, heat acclimation and aging

The kidneys' integrative responses to heat stress aid thermoregulation, cardiovascular control, and water and electrolyte regulation. Recent evidence suggests the kidneys are at increased risk of pathological events during heat stress, namely acute kidney injury (AKI), and that this risk is compounded by dehydration and exercise. This heat stress related AKI is believed to contribute to the epidemic of chronic kidney disease (CKD) occurring in occupational settings. It is estimated that AKI and CKD affect upwards of 45 million individuals in the global workforce. Water and electrolyte disturbances and AKI, both of which are representative of kidney-related pathology, are the two leading causes of hospitalizations during heat waves in older adults. Structural and physiological alterations in aging kidneys likely contribute to this increased risk. With this background, this comprehensive narrative review will provide the first aggregation of research into the integrative physiological response of the kidneys to heat stress. While the focus of this review is on the human kidneys, we will utilize both human and animal data to describe these responses to passive and exercise heat stress, and how they are altered with heat acclimation. Additionally, we will discuss recent studies that indicate an increased risk of AKI due to exercise in the heat. Lastly, we will introduce the emerging public health crisis of older adults during extreme heat events and how the aging kidneys may be more susceptible to injury during heat stress.

Exertional Rhabdomyolysis: A Retrospective Population-based Study

PURPOSE

This study aimed to evaluate the incidence and characteristics of exertional rhabdomyolysis (ER) in a population-based cohort.

METHODS

A retrospective cohort study was performed in Olmsted County, Minnesota, from 2003 to 2015. Incident ER cases were ascertained through the Rochester Epidemiology Project medical record linkage system through electronic searches of the International Classification of Diseases, Ninth Revision, codes and clinical note text. Population incidence rate was calculated using the corresponding Rochester Epidemiology Project census populations specific to calendar year and sex. Descriptive statistics were used.

RESULTS

Of the 430 patients, 431 cases met the inclusion criteria for rhabdomyolysis; 4.9% of cases (n = 20; males n = 18; Caucasian n = 17) were ER, with one recurrence. There were no deaths secondary to ER. The age- and sex-adjusted incidence rate of ER was 1.06 ± 0.24 (95% confidence interval = 0.59-1.52) per 100,000 person-years. Endurance activity (n = 7), manual labor (n = 5), and weight lifting (n = 4) were common causes. Complications included kidney injury (n = 5), mild electrolyte abnormalities (n = 10), elevated transaminases (n = 12), and minor electrocardiographic abnormalities (n = 4). A majority of patients were hospitalized (n = 16) for a median of 2 d, had mild abnormalities in renal and liver function and electrolytes, and were discharged without sequelae.

CONCLUSION

ER in the civilian population occurs at a much lower incidence than the military population. The most common causes were endurance exercise, manual labor, and weight lifting. The majority of cases were treated conservatively with intravenous fluid resuscitation during a brief hospital stay, and all were discharged without sequela. Only one case of recurrence occurred in this cohort, indicating the recurrence rate was low.

Injuries in Novice Participants during an Eight-Week Start up CrossFit Program-A Prospective Cohort Study

Background: Previously published studies have reported injury rates ranging from 0.74 to 3.3 per 1000 h of exposure in CrossFit participants. However, the existing body of evidence is mainly based on experienced participants; therefore, the injury incidence and injury rate within novice CrossFit participants remains relatively unknown. The aim of this study wasto investigate the injury incidence and injury rate among novice participants in an eight-week CrossFit program. Methods: This survey-based prospective cohort study included CrossFit Copenhagen’s novice members who began an eight-week, free-of-charge membership period. A questionnaire was distributed at baseline and at eight-week follow-up. Information about exposure was retrieved through the online booking system. Injury incidence, defined as proportion of participants who sustained an injury, and injury rates per 1000 h of exposure were calculated. Results: Among the 168 included participants, a total of 28 injuries (14.9%) were reported. The number of injured participants and total exposure time resulted in an injury rate per 1000 h of exposure of 9.5. Conclusions: Compared to the existing body of evidence, the findings in this study indicate that the risk of injuries is higher among novice participants than among experienced CrossFit participants.

High intensity resistance training causes muscle damage and increases biomarkers of acute kidney injury in healthy individuals

PURPOSE

High-intensity interval resistance training (HIIRT) is an increasingly popular exercise program that provides positive results with short sessions. This study aimed to evaluate whether an HIIRT session causes muscle and kidney damage.

METHODS

Fifty-eight healthy volunteers (median age 24 years, 50% women) participated in this study and performed a HIIRT session. The Borg CR10 scale for pain (CR10P) and blood and urine samples were collected before (baseline) and 2 and 24 hours after the HIIRT session. Blood samples were analyzed for serum creatinine (SCr), creatine kinase (CK) and myoglobin. Urine samples were assessed for creatinine, neutrophil gelatinase-associated lipocalin, interleukin 18, calbindin, microalbuminuria, trefoil factor-3 and β-2 microglobulin.

RESULTS

CR10P had a significant increase at 2 and 24 hours post-workout, and CK increased significantly at 2 hours and increased further at 24 hours. Myoglobin increased significantly at 2 hours and remained elevated at 24 hours. SCr increased modestly but significantly at 24 hours only in men. Three men met the KDIGO diagnostic criteria for acute kidney injury. The urinary kidney injury biomarkers increased significantly at 2 hours and returned to the baseline values 24 hours after HIIRT.

CONCLUSIONS

A single HIIRT session caused early and significant elevations in CK, myoglobin, SCr, microalbuminuria and urinary biomarkers indicative of kidney tubular injury, suggesting the occurrence of muscle and kidney damage.

Perfil de lesões em praticantes de CrossFit: revisão sistemática

RESUMO O CrossFit se apresenta como um novo método de treinamento físico que vem ganhando popularidade desde sua criação. O objetivo deste estudo foi analisar o perfil de lesões em praticantes de CrossFit por meio de uma revisão sistemática da literatura. Utilizaram-se as recomendações da Declaração PRISMA para condução da revisão sistemática. A busca foi realizada nas bases de dados CINAHL, SciELO, Science Direct, SCOPUS, LILACS, PEDro, PubMed, SPORTDiscus e Web of Science. Avaliou-se a qualidade metodológica dos estudos, entre os quais dez foram considerados elegíveis. A prevalência de lesões nos praticantes de CrossFit variou de 5 a 73,5%, e a taxa de lesão variou de 1,94 a 3,1 lesões a cada 1.000 horas de treinamento. A região corporal mais acometida por lesões nos estudos selecionados foram os ombros, seguidos pelas costas e joelhos. Em relação aos fatores associados às lesões, destacou-se o tipo de exercício realizado e o tempo de prática de CrossFit. O sexo apresentou associação com a prevalência de lesões, estudos demonstraram que os homens apresentaram maior número de lesões em relação às mulheres. A idade esteve entre os fatores que não estiveram associados às lesões. Conclui-se que os ombros são a região corporal mais comumente acometida entre os praticantes de CrossFit, em indivíduos do sexo masculino e com lesões prévias, muitas vezes obtidas em outras modalidades. Ainda, que o CrossFit pode ser praticado com segurança por indivíduos de 18 a 69 anos.

Cluster of exertional rhabdomyolysis in three young women

Three young women, aged 18-24 years, presented to general practice with signs and symptoms of exertional rhabdomyolysis in 2016. All attended the same gym and had undertaken an intensive physical workout. Presenting symptoms were severe muscle pain and swelling, significantly reduced range of motion in affected muscles and, in two cases, dark-coloured urine. One case had presented to the out-of-hours service 4 months previously with similar symptoms but rhabdomyolysis was not considered, although retrospective history taking suggests that was the likely diagnosis. All three women were admitted to hospital, treated with intravenous fluids and discharged between 1 and 6 days later. All made a full recovery with no renal sequelae. The cases were questioned about potential risk factors, and the only commonality was unaccustomed strenuous exercise.