Aerobic Capacity According to Playing Role and Position in Elite Female Basketball Players Using Laboratory and Field Tests

Purpose: To compare the aerobic capacity of elite female basketball players between playing roles and positions determined using maximal laboratory and field tests. Methods: Elite female basketball players from the National Croatian League were grouped according to playing role (starter: n = 8; bench: n = 12) and position (backcourt: n = 11; frontcourt: n = 9). All 20 players completed 2 maximal exercise tests in a crossover fashion 7 days apart. First, the players underwent a laboratory-based continuous running treadmill test with metabolic measurement to determine their peak oxygen uptake (VO2peak). The players then completed a maximal field-based 30-15 Intermittent Fitness Test (30-15 IFT) to estimate VO2peak. The VO2peak was compared using multiple linear regression analysis with bootstrap standard errors and playing role and position as predictors. Results: During both tests, starters attained a significantly higher VO2peak than bench players (continuous running treadmill: 47.4 [5.2] vs 44.7 [3.5] mL·kg−1·min−1, P = .05, moderate; 30-15 IFT: 44.9 [2.1] vs 41.9 [1.7] mL·kg−1·min−1, P < .001, large), and backcourt players attained a significantly higher VO2peak than frontcourt players (continuous running treadmill: 48.1 [3.8] vs 43.0 [3.3] mL·kg−1·min−1, P < .001, large; 30-15 IFT: 44.2 [2.2] vs 41.8 [2.0] mL·kg−1·min−1, P < .001, moderate). Conclusions: Starters (vs bench players) and guards (vs forwards and centers) possess a higher VO2peak irrespective of using laboratory or field tests. These data highlight the role- and position-specific importance of aerobic fitness to inform testing, training, and recovery practices in elite female basketball.

Imaging of glucose metabolism by 13C-MRI distinguishes pancreatic cancer subtypes in mice

Metabolic differences among and within tumors can be an important determinant in cancer treatment outcome. However, methods for determining these differences non-invasively in vivo is lacking. Using pancreatic ductal adenocarcinoma as a model, we demonstrate that tumor xenografts with a similar genetic background can be distinguished by their differing rates of the metabolism of 13C labeled glucose tracers, which can be imaged without hyperpolarization by using newly developed techniques for noise suppression. Using this method, cancer subtypes that appeared to have similar metabolic profiles based on steady state metabolic measurement can be distinguished from each other. The metabolic maps from 13C-glucose imaging localized lactate production and overall glucose metabolism to different regions of some tumors. Such tumor heterogeneity would not be not detectable in FDG-PET.

Validating the Commercially Available Garmin Fenix 5x Wrist-Worn Optical Sensor for Aerobic Capacity

Recreational exercisers continue to take a greater interest in monitoring their personal fitness levels. One of the more notable measurements that are monitored and estimated by wrist-worn tracking devices is maximum aerobic capacity (VO2max), which is currently the accepted measure of cardiorespiratory fitness. Traditional methods of obtaining VO2max present expensive barriers, whereas new wearable technology, such as of the Garmin Fenix 5x (GF5) provides a more cost-effective alternative. PURPOSE: To determine the validity of the GF5 VO2max estimation capabilities against the ParvoMedics TrueOne 2400 (PMT) metabolic measurement system in recreational runners. METHODS: Twenty-five recreational runners (17 male and 8 female) ages 18-55 participated in this study. Participants underwent two testing sessions: one consisting of the Bruce Protocol utilizing the PMT, while the other test incorporated the GF5 using the Garmin outdoor protocol. Both testing sessions were conducted within a few days of each other, with a minimum of 24 hours rest between sessions. RESULTS: The mean VO2max values for the PMT trial (49.1 ± 8.4 mL/kg/min) and estimation for the GF5 trial (47 ± 6.0 mL/kg/min) were found to be significantly different (t = 2.21, p = 0.037). CONCLUSION: The average difference between the GF5 estimation and the PMT was 2.16 ml/kg/min. Therefore, the watch is not as accurate compared to a PMT for obtaining VO2max. However, although not statically significant, the proximity of scores to the PMT shows that the GF5 can be an option for a person seeking an affordable and easily available method of determining VO2max.

The Varieties of Scrubbers, Tubing, and Tubing Connectors

This chapter discusses several often-neglected areas of respirometry infrastructure. These include the correct selection of scrubber chemicals for removing water vapor and/or carbon dioxide from air streams, without undesirable interactions; chemical-free scrubbing techniques such as selective membranes, thermal condensing systems, and mathematical correction for water vapor dilution; selecting tubing for metabolic measurement; evaluating the different tubing chemistries in light of the intended application; selecting appropriate tubing diameters for the flow rates that will be used; selecting tubing connectors; maintaining connector gender conventions to minimize plumbing confusion; and other related topics.

Measuring the Fire of Life: A Brief History of Metabolic Measurement

This chapter describes the evolution of respirometry from Leonardo da Vinci’s musings onwards. The works of Boyle, the brilliant and prophetic Mayow, and the well-intentioned but misguided Priestley are described. The bizarre dead-end theory of phlogiston and its apparent validity to the scientists of the day are explained in historical context. The breakthroughs of Lavoisier and Paulze, who realized the central role of oxygen and pioneered the quantitative measurement of metabolism, end the conventional historical part of the chapter, which concludes with a brief description of the deep history of the molecules most important to respirometry.

Measuring Metabolic Rates

Measuring Metabolic Rates demystifies the field of metabolic rate measurement, explaining every common variation of the art, from century-old manometric methods through ingenious syringe-based techniques, direct calorimetry, aquatic respirometry, stable-isotope metabolic measurement, and every type of flow-through respirometry. Each variation is described in enough detail to allow it to be applied in practice. Special chapters are devoted to metabolic phenotyping and human metabolic measurement, including room calorimetry. Background information on different analyzer and equipment types allows users to choose the best instruments for their application. Respirometry equations—normally a topic of terror and confusion to researchers—are derived and described in enough detail to make their selection and use effortless. Tools and skills—many of them open source—that will amplify the innovative researcher’s capabilities are described. Vital topics such as manual and automated baselining, implementing multi-animal systems, common pitfalls, and the correct analysis and presentation of metabolic data are covered in enough detail to turn a respirometry neophyte into a hardened metabolic warrior, ready to take on the task of publication in peer-reviewed journals with confidence.