Fitness-related Parameters Research Articles

Effect of Glycated Haemoglobin (HBA1c) on Cardiorespiratory Fitness (CRF) in a Population with Type 2 Diabetes Mellitus (T2DM): A Cross-Sectional Study

Background and Objective: The aim of this study was to evaluate cardiorespiratory fitness (CRF) measures, maximal oxygen consumption (VO2 max), and minute ventilation/carbon dioxide production (VE/VCO2 slope and others) among the T2DM population based on glycated haemoglobin (HBA1c). Material and Methods: The present study comprised a cross-sectional design, with two groups, based on HbA1c values (≤7 and ≥7.1). Laboratory samples were taken to evaluate glycated haemoglobin and fasting blood glucose (FBS). Cardiopulmonary exercise testing was performed to calculate various fitness-related parameters. Data analysis: An independent t-test was used to analyse the outcomes in the two groups. p < 0.05 was considered significant. Linear regression was used to examine the influence of predictor variables on dependent variables. Results: A total of 70 patients agreed to participate in the study, with 19 females and 51 males. The mean (standard deviation) BMI (body mass index) of all participants was 29.7(5.2), the mean (SD) weight was 84.4 (18.9) kg, and the mean height was 167.4 (23) cm. The average age of the individuals was 52 ± 8 years. The independent t-test revealed a significant difference between the two groups in terms of CRF measures. Conclusions: The current research identified the presence of poor glycaemic control and cardiorespiratory fitness measures among the Brazilian population with T2DM. HBA1c, duration of diabetes, age, and BMI can be employed to predict the ventilatory threshold (VT) and VO2 max.

The complex effects of modern oncogenic environments on the fitness, evolution and conservation of wildlife species.

Growing evidence indicates that human activities are causing cancer rates to rise in both human and wildlife populations. This is due to the inability of ancestral anti-cancer defences to cope with modern environmental risks. The evolutionary mismatch between modern oncogenic risks and evolved cancer defences has far-reaching effects on various biological aspects at different timeframes, demanding a comprehensive study of the biology and evolutionary ecology of the affected species. Firstly, the increased activation of anti-cancer defences leads to excessive energy expenditure, affecting other biological functions and potentially causing health issues like autoimmune diseases. Secondly, tumorigenesis itself can impact important fitness-related parameters such as competitiveness, predator evasion, resistance to parasites, and dispersal capacity. Thirdly, rising cancer risks can influence the species' life-history traits, often favoring early reproduction to offset fitness costs associated with cancer. However, this strategy has its limits, and it may not ensure the sustainability of the species if cancer risks continue to rise. Lastly, some species may evolve additional anti-cancer defences, with uncertain consequences for their biology and future evolutionary path. In summary, we argue that the effects of increased exposure to cancer-causing substances on wildlife are complex, ranging from immediate responses to long-term evolutionary changes. Understanding these processes, especially in the context of conservation biology, is urgently needed.

The impact of helping experience on helper life-history and fitness in a cooperatively breeding bird.

Cooperative breeding occurs when helpers provide alloparental care to the offspring of a breeding pair. One hypothesis of why helping occurs is that helpers gain valuable skills that may increase their own future reproductive success. However, research typically focuses on the effect of helping on short-term measures of reproductive success. Fewer studies have considered how helping affects long-term fitness measures. Here, we analyze how helping experience affects key breeding and fitness-related parameters in the Seychelles warbler (Acrocephalus sechellensis). Importantly, we control for females that have cobred (reproduced as a subordinate by laying an egg within a territory in which they are not a dominant breeder), as they already have experience with direct reproduction. Helping experience had no significant association with any of the metrics considered, except that helpers had an older age at first dominance. Accounting for helping experience, females that had cobred produced more adult offspring (≥1 year) after acquiring dominance and had a higher lifetime reproductive success (LRS) than females that had never cobred. Our results suggest that, in the Seychelles warbler, helping experience alone does not increase the fitness of helpers in any of the metrics considered, and highlights the importance of separating the effects of helping from cobreeding. Our findings also emphasize the importance of analyzing the effect of helping at various life-history stages, as higher short-term fitness may not translate to an overall increase in LRS.

Impact of genome duplications in drought tolerance and distribution of the diploid-tetraploid Jasione maritima.

Polyploidy has important ecological effects, including ploidy-mediated effects on morphology, breeding system and ecological tolerances. However, there is still little comprehensive research available to test its adaptive significance and its role in driving distributional patterns. This work aimed to assess the contribution of genome duplications to ecological divergence using an experimental approach with the diploid-tetraploid Jasione maritima polyploid complex. We explored if individuals with different ploidy differ in their tolerance to water deficit and if this may contribute to explaining the distribution patterns along a latitudinal gradient in the northwest Iberian Peninsula. For that, we used three cytogenetic entities: diploids and established tetraploids collected in natural populations along a latitudinal gradient, and neotetraploids synthesized from diploid populations after treatments with colchicine. Thirty plants from each of the nine populations were grown under controlled conditions with half randomly assigned to the water deficit treatment, and half used as control. We determined experimental plants' response by measuring fitness-related parameters, such as above and belowground biomass, plant water status, photosynthetic efficiency and pigments, membrane stability, antioxidant capacity and sugars content. Our data shows that biomass, chlorophyll content, photochemical quenching (qP) and non-photochemical quenching (NPQ) in neotetraploids and established tetraploids were significantly higher than in diploids and that these differences could be attributed to genome duplications. In response to the water deficit, diploids seem to use a strategy of avoidance, whereas tetraploids seem to employ the strategy of tolerance to overcome water deficit stress, which appears equally efficient. Additionally, we did not observe a response pattern along the latitudinal gradient of the distributional range of the J. maritima complex. The results indicate that the response to water deficit is population dependent. Further studies are necessary to understand the role of ploidy in explaining the distribution patterns of the J. maritima complex.

Jump Rope Training for Health and Fitness in School-age Participants: Secondary Analyses from a Systematic Review

Background: Altering moderator variables during a jump rope training (JRT) program can provide a novel training modification that can be used to modify the specific training outcomes. JRT is commonly implemented as a traditional game activity in many countries as an old culture of physical activity in school-age participants (SAP). However, strength and conditioning professionals need to know how JRT moderator variables affect these health- and physical fitness outcomes. Thus, an evidence-gap map (EGM) could provides a clearer picture of the design of an appropriate JRT based on scientific evidence. Objective: the purpose of this systematic review secondary analysis was to assess the moderator variables related to JRT effectiveness for health and physical fitness-related outcomes in SAP. Method: literature searches were conducted in the following electronic databases: PubMed, Web of Science and SCOPUS. The PICOS (participants, intervention, comparators, outcomes, and study design) approach was used to rate studies for eligibility. An EGM was constructed to graphically represent the body of evidence and the current research gaps. Results: 10,546 records were initially identified and finally, 8 studies were considered. A total of 186 participants were analysed in the intervention groups (16 groups). Five of Eight studies measured health-related parameters and five of eight included fitness-related parameters. Conclusion: rope weight (e.g., weighted rope i.e. 695 g), adequate post-exercise recovery strategies (e.g., dark chocolate supplementation), type of jump (e.g., freestyle), and total number of jumps, can be

Physical Fitness and Maternal Psychosocial Status in Children With Autism Attending a Regular Physical Activity Program

The aim of this study was to compare physical fitness-related parameters in Turkish children with mild to moderate autism and their typically developing (TD) peers to determine maternal anxiety level and quality of life. Children with autism had significantly worse scores for all Munich Fitness Test (MFT) parameters except step test heart rate and had lower physical activity levels compared to the TD children ( p < .05). There was no difference between groups in terms of postural deviations or maternal anxiety scores ( p > .05). The MFT total score was associated with higher maternal quality of life scores ( r = .605, p = .006). This study showed that despite participating in a regular physical activity program, children with mild to moderate autism have lower physical fitness and activity levels compared to their TD peers, whereas better physical fitness in children with autism has a positive effect on their mothers’ quality of life.

Do Age, Fitness and Concomitant Medications Influence Management and Outcomes of CLL Patients Treated with Ibrutinib?

Do Age, Fitness and Concomitant Medications Influence Management and Outcomes of CLL Patients Treated with Ibrutinib?

Long-term capture and handling effects on body condition, reproduction and survival in a semi-aquatic mammal

In long-term individual-based field studies, several parameters need to be assessed repeatedly to fully understand the potential fitness effects on individuals. Often studies only evaluate capture stress that appears in the immediate weeks or breeding season and even long-term studies fail to evaluate the long-term effects of their capture procedures. We investigated effects of long-term repeated capture and handling of individuals in a large semi-aquatic rodent using more than 20 years of monitoring data from a beaver population in Norway. To investigate the effects, we corrected for ecological factors and analysed the importance of total capture and handling events, years of monitoring and deployment of telemetry devices on measures related to body condition, reproduction and survival of individual beavers. Body mass of dominant individuals decreased considerably with number of capture events (107 g per capture), but we found no statistically clear short or long-term effects of capture and handling on survival or other body condition indices. Annual litter size decreased with increasing number of captures among older individuals. Number of captures furthermore negatively affected reproduction in the beginning of the monitoring, but the effect decreased over the years, indicating habituation to repeated capture and handling. By assessing potential impacts on several fitness-related parameters at multiple times, we can secure the welfare of wild animal populations when planning and executing future conservation studies as well as ensure ecologically reliable research data.

The effect of a three month, low-load- high-repetitions group-based exercise program versus pilates on physical fitness and body composition in inactive women

ObjectiveBoth low-load-high-repetitions (LLHR) and Pilates programs constitute popular forms of exercise, accompanied by health benefits for the participants involved. Notably, the effect of such programs on aerobic fitness is still controversial. The aim of this study was to examine the effects of both programs on physical fitness and body composition on previously inactive adult women. MethodsTwenty-six women (39.8 ± 9.1y) were assigned to a LLHR program, and sixteen women (39.1 ± 12.2y) were assigned to a Pilates program. Both programs were performed in a group setting, 3 times per week for 3 months. Aerobic fitness, flexibility, handgrip strength and lower extremities explosiveness were assessed by a battery of field testing. Total body fat and trunk fat levels were assessed by bioelectrical impedance analysis. Heart rate response during exercise was recorded once every month by using a telemetry system. ResultsAerobic fitness, lower extremities explosive power, left arm handgrip strength and body composition significantly improved in the LLHR group; while flexibility significantly improved only in the Pilates group, following the intervention period (p < 0.05). LLHR was superior to the Pilates program in improving aerobic fitness and body composition; whilst Pilates was superior in improving flexibility (p < 0.05). ConclusionLLHR group-based exercise programs may improve various aspects of physical fitness, including aerobic fitness, in inactive adult women. This medium-intensity form of exercise is generally well tolerated and might be used as an option for women who cannot perform training on higher intensities. In contrast, the Pilates program failed to improve physical fitness-related parameters except flexibility levels.

Assisted species migration and hybridization to conserve cold-adapted plants under climate change.

Temperature rise due to climate change is putting many arctic and alpine plants at risk of extinction because their ability to react is outpaced by the speed of climate change. We considered assisted species migration (ASM) and hybridization as methods to conserve cold-adapted species (or the genes thereof) and to minimize the potential perturbation of ecosystems due to climate change. Assisted species migration is the deliberate movement of individuals from their current location to where the species' ecological requirements will be matched under climate projections. Hybridization refers to crossbreeding of closely related species, where for arctic and alpine plants, 1 parent is the threatened cold-adapted and the other its reproductively compatible, warm-adapted sibling. Traditionally, hybridization is viewed as negative and leading to a loss of biodiversity, even though hybridization has increased biodiversity over geological times. Furthermore, the incorporation of warm-adapted genes into a hybrid may be the only means for the persistence of increasingly more maladapted, cold-adapted species. If approached with thorough consideration of fitness-related parameters of the source population and acknowledgement of the important role hybridization has played in shaping current biodiversity, ASM and hybridization could help save partial or whole genomes of key cold-adapted species at risk due to climate change with minimal negative effects on ecosystem functioning.

Effect of UV-Absorbing Nets on the Performance of the Aphid Predator Sphaerophoria Rueppellii (Diptera: Syrphidae).

Photoselective nets have proven to be effective for aphid pest control as they limit their dispersal ability. However, little is known on the impact of such nets on natural enemies of aphids. In this work, we study the effect of UV-absorbing nets on the syrphid fly Sphaerophoria rueppellii Wiedemann (Diptera: Syrphidae), a commercially available aphid biocontrol agent in Mediterranean horticultural crops. First, we released mature syrphid adults and evaluated density and dispersal of the resulting immatures in a turnip crop grown under either UV-blocking (Bionet) or standard net. Second, we assessed, under controlled conditions, the impact of UV radiation on fitness-related parameters, and on flight behavior of S. rueppellii adults. Results showed that, while syprhid immature density was higher, their dispersion was reduced under Bionet. UV-absorbing nets are known to influence the dispersion pattern of aphids, which may have indirectly conditioned the distribution of their predator S. rueppellii. On the other hand, the type of net had no influence on the performance of adults. We conclude that the use of photoselective nets and the release of syrphid predators such S. rueppellii are compatible strategies to be used in IPM aphid-control programs.

Evaluating the effect of dorsal muscle biopsies on adult Atlantic salmon growth and marine return rates.

Increasing conservation and animal-welfare concerns have driven the development of non-lethal sampling of fish populations, with the use of muscle tissue biopsies now being routinely applied as a sampling method in the wild. Crucial to the success of non-lethal sampling, however, is an evaluation of the short- and long-term consequences of the treatment and ultimately the determination of how these may affect organism mortality and other fitness-related traits. The current study evaluated the use of a dorsal muscle biopsies on post-spawned Atlantic salmon emigrating to sea and undertaking a 2-month long-feeding migration before returning to spawn. Using mark-recapture, return rates and growth were compared between fish that were biopsied and externally tagged, and a control group tagged only with external tags. The biopsy treatment showed no lasting effects on fish as estimated from the two key fitness-related parameters. Results, therefore, suggest the technique can be more widely applied to gather information on marine migrating Atlantic salmon and other anadromous fishes that can be intercepted as they descend and ascend rivers during seasonal migrations. Coupled with modern tagging technologies, the use of biopsies may facilitate an improved understanding of movement and its consequences in terms of feeding patterns and growth.

Depressive symptoms, sleep quality, physical fitness, and fatigue among adult women with different obesity status

The aim of this cross-sectional study was to examine the association between depressive symptoms, sleep quality, objectively assessed physical fitness, and fatigue, among a sample of adult women with different obesity status. One hundred and ninety-four volunteer adult women (36.1 ± 11.1 years) participated in the study. Based on body mass index (BMI), the participants were allocated into three groups: normal weight (n = 134), overweight (n = 32), and obese (n = 25). Physical fitness-related parameters such as aerobic fitness, flexibility, lower limb explosive strength, isometric handgrip strength, and sprint performance were assessed with a battery of field tests. Total body fat and trunk fat levels were assessed by bioelectrical impedance analysis. Depressive symptoms were assessed using the Beck depression inventory, sleep quality was assessed using the Pittsburg sleep quality index, and fatigue levels were examined using the fatigue severity scale. Obese women experienced a significantly worse score regarding depressive symptoms (p < 0.05). Similarly, the obese and overweight women were found to exhibit lower levels of aerobic fitness compared to women with normal BMI (p < 0.05). All examined body composition variables were shown to be inversely associated with the score on all physical fitness tests as well as with poor sleep, depressive symptoms, and fatigue levels (p < 0.05). Depressive symptoms and performance on various physical fitness tests were found to be significantly impaired in obese and overweight adult women indicating the negative impact of increased body weight in health and well-being.

Extreme temperature impairs growth and productivity in a common tropical marine copepod

Shallow, tropical marine ecosystems provide essential ecosystem goods and services, but it is unknown how these ecosystems will respond to the increased exposure to the temperature extremes that are likely to become more common as climate change progresses. To address this issue, we tracked the fitness and productivity of a key zooplankton species, the copepod Pseudodiaptomus annandalei, acclimated at two temperatures (30 and 34 °C) over three generations. 30 °C is the mean temperature in the shallow water of the coastal regions in Southeast Asia, while 34 °C simulated a temperature extreme that occurs frequently during the summer period. For each generation, we measured the size at maturity and reproductive success of individuals. In all three generations, we found strong negative effects of warming on all measured fitness-related parameters, including prolonged development time, reduced size at maturity, smaller clutch sizes, lower hatching success, and reduced naupliar production. Our results suggest that P. annandalei are already exposed to temperatures that exceed their upper thermal optimum. Increased exposure to extreme temperatures may reduce the abundance of these tropical marine copepods, and thus reduce the availability of resources to higher trophic levels.

Effects of host age and radiation dose in Diachasmimorpha longicaudata (Hymenoptera: Braconidae) mass-reared on medfly larvae of the tsl Vienna 8 genetic sexing strain

Augmentative release of parasitoids against Ceratitis capitata (Weidemann) is currently at an early stage in Argentina. The success of this environment-friendly strategy depends on suitable mass-rearing procedures. The integration of radiation in the rearing process improves both mass production and handling of fruit fly parasitoids. Diachasmimorpha longicaudata (Ashmead) is reared on larvae of tsl Vienna-8 C. capitata strain at the BioPlanta San Juan, Argentina. The aim of the current study was to identify the best combination of larval host age, exposure time, and host gamma-radiation dose to achieve the greatest parasitoid mass yield with the highest female-biased offspring ratio. The effect of host radiation doses on parasitoid fitness-related parameters from the first filial generation was also assessed. Firstly, host larvae aged 5–7 d-old were exposed to parasitoids for 30, 60, 90, 120, 150 and 180 min at a constant 4:1 host/parasitoid ratio. The most productive exposure procedure was 5–6 d-old larvae for 1.30 h. Secondly, batches of 180,000 naked host larvae aged 5–6 d-old were irradiated at 0, 60, 65, 70, 75, 80, 85, 90, 95, and 100 Gy. Suitable radiation doses for wholly suppressing host emergence were at 85–100 Gy. Thirdly, 5–6 d-old host larvae irradiated at 85, 90, 95, and 100 Gy were exposed to parasitoids. 6 d-old larva irradiated at 90 Gy was the most suitable combination to achieve the highest parasitoid emergence and female offspring values. Increasing radiation doses beyond 90 Gy did not significantly enhance parasitoid yield and did not improve female-biased offspring ratio. Fourthly, survival, fecundity, sex ratio, development time and parasitoid offspring size were not adversely affected by radiation. Gross fecundity and net reproductive rates, and sex ratio remarkably improved in comparison to that recorded on parasitoids reared on non-irradiated larvae. These findings greatly encourage the use of augmentative biological control against medfly in Argentina.

Prey-specific impact of cold pre-exposure on kill rate and reproduction.

Temperature influences biological processes of ectotherms including ecological interactions, but interaction strengths may depend on species-specific traits. Furthermore, ectotherms acclimate to prevailing thermal conditions by adjusting physiological parameters, which often implies costs to other fitness-related parameters. Both predators and prey may therefore pay thermal acclimation costs following exposure to suboptimal temperatures. However, these costs may be asymmetrical between predator and prey, and between the predator and different species of concurrent prey. We investigated whether thermal pre-exposure affected subsequent kill rate and predator fitness when foraging on prey that differ in ease of capture, and whether changes were primarily caused by predator or by prey pre-exposure effects. Specifically, we were interested in whether there were interactions between predator pre-exposed temperature and specific prey. Using the mesostigmatid mite Gaeolaelaps aculeifer as a generalist predator and the collembolans Folsomia candida and Protaphorura fimata as prey, we measured the impact of present temperature, predator pre-exposure temperature, prey pre-exposure temperature (all 10 or 20°C), prey species, and all interactions on prey numbers killed, predator eggs produced, and exploitation of killed prey in a full factorial design. Mites killed P.fimata in equal numbers independent of the presence of F.candida, but killed F.candida when P.fimata was absent. Mite kill rate and reproduction were significantly affected by mite pre-exposure temperature and test temperature, but not by prey pre-exposure temperature. Significantly more of the slower prey was killed than of the quicker prey. Importantly, we found significant synergistic negative interaction effects between predator cold pre-exposure and hunting prey of higher agility on predator kill rate and reproduction. Our findings show that the negative effects of cold and cold pre-exposure on kill rate and reproduction may be more severe when predators forage on quick prey. The study implies that predator cold exposure has consequences for specific prey survival following cold due to altered predation pressures, which in nature should influence the specific prey population dynamics and apparent competition outcomes. The findings exemplify how not only current but also preceding conditions affect ecological interactions, and that effect strength depends on the species involved.

Differential effects of abiotic conditions on fitness-related parameters of two Euseius species inhabiting avocado agro-ecosystems

Temperature and relative humidity are important factors in shaping the structure and dynamics of communities composed of ectothermic species, as they directly affect fitness-related parameters and biotic interactions. In a climate change context, increased warming and dryness will likely affect arthropod communities of agro-ecosystems managed by biological pest control. In this work, we compare, at the individual level, the functional relation between temperature and relative humidity and different life-history parameters in two sister predatory mite species that inhabit Spanish avocado crops, Euseius stipulatus and E. scutalis (Athias-Henriot) (Acari: Phytoseiidae). We found that negative effects of high temperature and low relative humidity were stronger in E. stipulatus than in E. scutalis. That E. scutalis tolerates very well hot and dry environments makes the species a good candidate to be considered in the future as a biocontrol agent against pests in subtropical and Mediterranean orchards.

Evidence of reproductive senescence of released individuals in a reinforced bird population

In free-ranging populations, age-dependent variation in fitness related parameters, in particular the pattern of senescence, has major eco-evolutionary implications and potential influence on population dynamics. Despite the recent surge of studies of senescence in the wild, senescence patterns in species for which population dynamics assessments are crucial, such as translocated populations, remain virtually unexplored. Based on a 15-year nest survey of a North-African Houbara bustard population in Morocco, we investigated age variation in the breeding performance of captive-bred females released in the wild. We identified 781 females, from 1 to 10years of age, on 1094 nests. We examined how age influenced nest initiation date, clutch size, egg volume, daily nest survival and daily brood survival, as well as whether age-dependent patterns varied according to environmental conditions. Most breeding parameters exhibited variation, suggesting an increase in breeding performance with age in young females (those from 1 to 3years old). In older females (>7–8years old), the egg volume and clutch size decreased with age, in concordance with expectations from senescence theories and previous empirical results obtained from captive Houbara bustards. Finally, our analysis uncovered a significant interaction between age and the amount of precipitation prior to the breeding season on clutch size, suggesting differential abilities of females of different ages to increase their breeding investment. Our study suggests that life histories in translocated individuals are not affected by translocation protocols and provides insights for implementing age dependencies in population viability assessments.

Evaluating dispersal potential of an invasive fish by the use of aerobic scope and osmoregulation capacity.

Non-indigenous species (NIS) can impact marine biodiversity and ecosystem structure and function. Once introduced into a new region, secondary dispersal is limited by the physiology of the organism in relation to the ambient environment and by complex interactions between a suite of ecological factors such as presence of predators, competitors, and parasites. Early prediction of dispersal potential and future ‘area of impact’ is challenging, but also a great asset in taking appropriate management actions. Aerobic scope (AS) in fish has been linked to various fitness-related parameters, and may be valuable in determining dispersal potential of aquatic invasive species in novel environments. Round goby, Neogobius melanostomus, one of the most wide-ranging invasive fish species in Europe and North America, currently thrives in brackish and fresh water, but its ability to survive in high salinity waters is unknown to date. We show that AS in round goby is reduced by 30% and blood plasma osmolality increased (indicating reduced capacity for osmoregulation) at salinities approaching oceanic conditions, following slow ramping (5 PSU per week) and subsequent long-term acclimation to salinities ranging between 0 and 30 PSU (8 days at final treatment salinities before blood plasma osmolality measurements, 12–20 additional days before respirometry). Survival was also reduced at the highest salinities yet a significant proportion (61%) of the fish survived at 30 PSU. Reduced physiological performance at the highest salinities may affect growth and competitive ability under oceanic conditions, but to what extent reduced AS and osmoregulatory capacity will slow the current 30 km year-1 rate of advance of the species through the steep salinity gradient from the brackish Baltic Sea and into the oceanic North Sea remains speculative. An unintended natural experiment is in progress to test whether the rate of advance slows down. At the current rate of advance the species will reach the oceanic North Sea by 2018/2019, therefore time for taking preventative action is short.

Fitness improvement of show jumping horses with deep water treadmill training

Athletes, including equine athletes need high intensity training in order to achieve high performance. However, continuous high intensity training often results in injuries to the locomotive system. The buoyancy of water reduces the force born on joints; therefore, training in water has been used for rehabilitation purposes both in humans and horses. The few studies dealing with water treadmill training of horses suggest that the fitness of horses can be improved using this training method, but none tested the subsequent performance of horses after water training. Therefore, the aim of this study was to test the effect of water training of varying intensity on the fitness-related parameters of show jumpers during training and after competition. Four similarly trained show jumper sport horse (aged between 7−11 years) competing at the same level (110 cm) were selected. Horses were subjected to 44-min deep water treadmill training with three intensities (9, 11, 13 km/h maximum speed) three times a week in addition to their normal training. At the conclusion of the week, horses participated in a two-day indoor show jumping event. Blood samples (4 ml) were taken from the jugular vein during the third water training and before and after the completion of the show jumping course on each day. From the blood plasma, lactate dehydrogenase (LDH), creatine kinase (CK) and aspartate aminotransferase (AST) activities, as well as lactate, glucose and triglyceride levels were determined. Data analysis was carried out with SAS (SAS Inst. Inc., Cary, USA) using the GLM procedure and Duncan’s new multiple range test. Pearson correlation coefficients were calculated between the same blood parameters from different sampling times. No interactions were detected between training intensity and sampling time during water training. Plasma lactate and glucose levels were decreased during the water training, while values increased afterwards. In contrast, heart rate, triglyceride and cortisol levels were elevated as a result of water training. Increasing the maximum speed of the water treadmill had no influence on the average heart rate of horses subjected to the training. Plasma lactate levels decreased with the increased maximum speed of the water trainer. Activities of AST, CK, LDH, and levels of cholesterol, cortisol and bilirubin decreased when the maximum speed of the treadmill was set to 11 km/h compared to the 9 km/h training. Water training resulted in lower heart rate measured right after completing the show jumping course when horses were subjected to medium intensity water training. The AST, CK and LDH activities measured before and after water training had only weak to moderate positive correlations with values measured after competition. In conclusion, our results indicate that deep-water training alters the biochemical processes and can improve the aerobic energy supply of show jumpers. Water training is a strenuous exercise, which initially leads to increased muscle damage. However, this initial phase is followed by subsequent adaptation.