Bone Metabolism During Exercise and Recovery: The Influence of Plasma Volume and Physical Fitness

Abstract

Understanding the reaction of bone to physical exercise is important for the development of strategies to increase and maintain bone mass. In this study the aim was to investigate the relationship among exercise intensity, physical capacity, and the biochemical responses, estimated by measuring biochemical markers of bone metabolism in serum. As a complement to the circulating concentrations we also accounted for the plasma volume shifts during and after exercise. The study included 10 men and 10 women, mean age 29 years, with a wide range of physical capacity, who performed a standardized running exercise test on a motor-driven treadmill with loads corresponding to 47 and 76% of VO2 max (maximal oxygen uptake) followed by a maximal effort until exhaustion. Total work time was about 35 minutes. Venous blood samples were drawn at rest, after each load, and after 30 minutes and 24 hours of recovery. The reductions in plasma volume during exercise were 4.3% (P < 0.05) and 15.1% (P < 0.001) whereas after 24 hours in recovery there was an expansion of 7.5% (P < 0.001). There were marked, intensity-related, increases of PICP and tALP concentrations (P < 0.001) during exercise. Since these were of the order of plasma volume reduction they did not correspond to a change in the calculated circulating amount (content). However, as the concentrations returned to basal during recovery, the total circulating amounts were increased at this point (P < 0.05). Osteocalcin was also increased during recovery (P < 0.01), although concentrations were unchanged during the entire study. The amount (P < 0.001) and concentration (P < 0. 05) of ICTP were also increased during follow-up. Serum PTH concentrations rose (P < 0.05) in proportion to the intensity of exercise and remained elevated during recovery. The subjects' VO2 max demonstrated positive relationships to the biochemical responses to exercise in bone and BMD of the legs, and a negative relationship to basal PTH levels. Bone turnover and PTH secretion was stimulated by exercise, and low basal levels of PTH and high BMD were induced by a high level of physical fitness. These observations correlate well with the favorable effects of exercise and training on bone mass.

Changes in Bone Metabolism and Antioxidant Status with Combined Exercise and Honey Supplementation in Young Female Rats

“…Previous studies on the effects of exercise on serum calcium were inconsistent. Increase in serum calcium has been observed following physical activities [23]. The absence of significant effects with jumping exercise alone on serum total calcium in the present study was consistent with Maimoun et al [24] which reported that a single session of strenuous exercise did not result in any significant change in serum total calcium.…”

Changes of Bone Metabolism Markers and Muscular Performance with Combined Aerobic Dance Exercise and Honey Supplementation in Adult Women

“…However, significant change in serum osteocalcin was not observed in this previous study. Meanwhile, Brahm et al 41 reported that running on a treadmill with 76% of VO 2max followed by a maximal effort until exhaustion resulted significant increases of 1CTP and osteocalcin levels during 24 hours of recovery. The authors speculated that during exercise, plasma content decreased and resulted diffusion of osteocalcin to the extravascular space.…”

Análise de parâmetros bioquímicos séricos e urinários em atletas de meia maratona

“…Além disso, a concentração de ferro sérico livre mostrou uma elevação significativa (p = 0,028), e esse achado pode ser indicativo de hemólise. Exercícios físicos extenuantes podem produzir hemoglobinúria assintomática, em que a hemólise pode ser decorrente do impacto dos pés no solo, aumento da força de cisalhamento do sangue periférico nas paredes dos vasos, decréscimo da concentração de óxido nítrico, bem como estresse oxidativo (12,20,(33)(34)(35). Por outro lado, os resultados de bilirrubina e urobilinogênio urinário após o esforço não mostraram diferença significativa.…”

“…O treino de resistência pode provocar uma expansão volêmica, o que justificaria uma queda na concentração de hemoglobina nos atletas. Nesses casos, ocorre um fenômeno reacional e transitório chamado pseudoanemia dilucional (11,33,34), o que não foi o caso. A análise da concentração de ferro sérico e do índice de saturação da transferrina mostrou uma significativa elevação após a prova (p < 0,05).…”