ISSN exercise & sport nutrition review: research & recommendations

Sports nutrition is a constantly evolving field with hundreds of research papers published annually. For this reason, keeping up to date with the literature is often difficult. This paper is a five year update of the sports nutrition review article published as the lead paper to launch the JISSN in 2004 and presents a well-referenced overview of the current state of the science related to how to optimize training and athletic performance through nutrition. More specifically, this paper provides an overview of: 1.) The definitional category of ergogenic aids and dietary supplements; 2.) How dietary supplements are legally regulated; 3.) How to evaluate the scientific merit of nutritional supplements; 4.) General nutritional strategies to optimize performance and enhance recovery; and, 5.) An overview of our current understanding of the ergogenic value of nutrition and dietary supplementation in regards to weight gain, weight loss, and performance enhancement. Our hope is that ISSN members and individuals interested in sports nutrition find this review useful in their daily practice and consultation with their clients

High Climate Model Dependency of Pliocene Antarctic Ice-Sheet Predictions

The mid-Pliocene warm period provides a natural laboratory to investigate the long-term response of the Earth’s ice-sheets and sea level in a warmer-than-present-day world. Proxy data suggest that during the warm Pliocene, portions of the Antarctic ice-sheets, including West Antarctica could have been lost. Ice-sheet modelling forced by Pliocene climate model outputs is an essential way to improve our understanding of ice-sheets during the Pliocene. However, uncertainty exists regarding the degree to which results are model-dependent. Using climatological forcing from an international climate modelling intercomparison project, we demonstrate the high dependency of Antarctic ice-sheet volume predictions on the climate model-based forcing used. In addition, the collapse of the vulnerable marine basins of Antarctica is dependent on the ice-sheet model used. These results demonstrate that great caution is required in order to avoid making unsound statements about the nature of the Pliocene Antarctic ice-sheet based on model results that do not account for structural uncertainty in both the climate and ice sheet models

The topographic evolution of the Tibetan Region as revealed by palaeontology

The Tibetan Plateau was built through a succession of Gondwanan terranes colliding with Asia during the Mesozoic. These accretions produced a complex Paleogene topography of several predominantly east–west trending mountain ranges separated by deep valleys. Despite this piecemeal assembly and resultant complex relief, Tibet has traditionally been thought of as a coherent entity rising as one unit. This has led to the widely used phrase ‘the uplift of the Tibetan Plateau’, which is a false concept borne of simplistic modelling and confounds understanding the complex interactions between topography climate and biodiversity. Here, using the rich palaeontological record of the Tibetan region, we review what is known about the past topography of the Tibetan region using a combination of quantitative isotope and fossil palaeoaltimetric proxies, and present a new synthesis of the orography of Tibet throughout the Paleogene. We show why ‘the uplift of the Tibetan Plateau’ never occurred, and quantify a new pattern of topographic and landscape evolution that contributed to the development of today’s extraordinary Asian biodiversity

Snowmelt controls on concentration-discharge relationships and the balance of oxidative and acid-base weathering fluxes in an alpine catchment, East River, Colorado

Although important for riverine solute and nutrient fluxes, the connections between biogeochemical processes and subsurface hydrology remain poorly characterized. We investigate these couplings in the East River, CO, a high-elevation shale-dominated catchment in the Rocky Mountains, using concentration-discharge (C-Q) relationships for major cations, anions, and organic carbon. Dissolved organic carbon (DOC) displays a positive C-Q relationship with clockwise hysteresis, indicating mobilization and depletion of DOC in the upper soil horizons and emphasizing the importance of shallow flow paths during snowmelt. Cation and anion concentrations demonstrate that carbonate weathering, which dominates solute fluxes, is promoted by both sulfuric acid derived from pyrite oxidation in the shale bedrock and carbonic acid derived from subsurface respiration. Sulfuric acid weathering dominates during base flow conditions when waters infiltrate below the inferred pyrite oxidation front, whereas carbonic acid weathering plays a dominant role during snowmelt as a result of shallow flow paths. Differential C-Q relationships between solutes suggest that infiltrating waters approach calcite saturation before reaching the pyrite oxidation front, after which sulfuric acid reduces carbonate alkalinity. This reduction in alkalinity results in CO2 outgassing when waters equilibrate to surface conditions, and reduces the riverine export of carbon and alkalinity by roughly 33% annually. Future changes in snowmelt dynamics that control the balance of carbonic and sulfuric acid weathering may substantially alter carbon cycling in the East River. Ultimately, we demonstrate that differential C-Q relationships between major solutes can provide unique insights into the complex subsurface flow and biogeochemical dynamics that operate at catchment scales

Warm and cold wet states in the western United States during the Pliocene–Pleistocene

The size distribution of lakes records the competition between precipitation delivery and evaporation. Lakes were abundant in the terminally draining basins of the western United States (USA) during both the colder-than-preindustrial latest Pleistocene glacial period (ca. 14–29 ka) and the warmer-than-preindustrial mid-Pliocene (ca. 2.9–3.3 Ma). To understand the hydroclimatic conditions that permitted lakes, we couple lake mass balance equations with a water and energy balance framework (sensu Budyko). Further, we compare paleo-lake area distributions to forward-modeled lake areas using climate model simulations of the Last Glacial Maximum (LGM, 19–26 ka) and mid-Pliocene. We conclude that both warmer- and colder-than-modern periods of the Pliocene–Pleistocene resulted in wetter-than-modern conditions in the terminally draining basins of the western USA through similar mechanisms. Specifically, the presence of lakes during the LGM reflects increased precipitation in addition to decreased evaporative demand. In the southern Great Basin, LGM lakes require large increases in precipitation across the region. During the mid-Pliocene, increased evaporative demand necessitated increased precipitation to maintain lakes. Further, the increase in precipitation and dominantly southwestern distribution of mid-Pliocene lake deposits is consistent with proposed mean “El Niño–like” conditions altering regional hydroclimate during this period. These observations suggest that during interglacial periods, the western USA resides within a local aridity maximum, and both long-term increases and decreases in global temperatures have been associated with wetter conditions across much of the western USA in the past

Effects of Fetal Programming on Osteoporosis

This chapter deals with the bone metabolic syndrome programmed by fetal nutritional deprivation, and the effect of compensatory growth from over-feeding in early life. The prophylaxis and treatment of the resulting conditions of osteoporosis and osteopenia are complex processes and depend on multi-professional cooperation. Aspects of nutrition-dependant embryogenesis are discussed, together with the need for hormonal, vitamin and mineral supplementation in cases of pathological osteogenesis. Clinical examples are presented of nutritionally-deprived pregnant women during World War Two and the late effects of intrauterine malnutrition on the bone quality of their offspring. In addition, one case suggestive of transgenerational transfer is presented, with a woman who had been nutritionally deprived as a fetus later having a son who in early middle age began showing typical signs of fetal nutritional deprivation even though his own intrauterine nutrition had been normal. The public health issue of fetal nutrition and bone quality in peoples migrating from famine-affected backgrounds to developed countries is also raised