The Physiological Effects of Beverage Ingestion During Cross Country Ski Training in Elite Collegiate Skiers

1998 ◽  
Vol 23 (1) ◽  
pp. 66-73 ◽  
Author(s):  
John G. Seifert ◽  
Maurie J. Luetkemeier ◽  
Andrea T. White ◽  
Liz M. Mino

The purpose of this study was to investigate the effects of beverage ingestion on fluid balance during 1.5 hr of low intensity cross country skiing. In Part I, 6 skiers drank water ad libitum during ski training. In Part II, 10 skiers were matched by body weight (BW) and assigned to ingest 2.5 ml kg−1 BW of water or a carbohydrate/electrolyte (CE) beverage every 2.5 km. Skiing speed averaged 11.5 km hr−1 for 90 min around a 5 km groomed track. Following 20 min of seated rest, blood samples were collected immediately before and approximately 30 min after skiing. Part I data indicated that subjects ingested 576 ± 189 ml of fluid and produced 266 ± 205 ml of urine: BW, plasma and urine osmolality, and plasma protein decreased significantly. In Part II, the CE group produced less urine (135 u75 vs 450 ± 262 ml) and had smaller decreases in plasma osmolality (−1.0 ± 1.0 vs. −7.0 ± 2.4 mOsm kg H2O) and protein (−0.11 ± 08 vs. −0.42 ± 0.24 g L−1) than the water group. No differences were observed for BW loss, % change in PV, FWC, or change in urine osmolality. It was concluded that ad lib water ingestion was inadequate to minimize fluid balance disruption, Plain water ingestion also led to significant dilution of the plasma and increased urine output. However, the ingestion of CE led to attenuation of fluid balance disruption, presumably due to the maintenance of osmotic balance in the plasma. Key words: fluid balance, cross country skiing

1986 ◽  
Vol 250 (6) ◽  
pp. F1008-F1012 ◽  
Author(s):  
U. Schwertschlag ◽  
J. G. Gerber ◽  
J. S. Barnes ◽  
A. S. Nies

The relationship of renal prostaglandin E2 (PGE2) excretion (UPGEV) to water deprivation, water diuresis, and subsequent antidiuresis by 1-desamino-8-D-arginine vasopressin (dDAVP) was studied in female volunteers. After 16 h of water deprivation, the subjects began a sustained water diuresis for 8 h. This diuresis caused a transient twofold rise in UPGEV at 2 h (P less than 0.05), which then fell back to or below baseline levels. dDAVP given during the water diuresis caused a transient rise of UPGEV as urine volume decreased and plasma osmolality fell from 277 +/- 1.5 to 271 +/- 2 mosmol/kg (P less than 0.01). Another group of subjects had the water diuresis discontinued after 4 h with dDAVP given at the 5th h when urine volume was decreasing and urine osmolality was increasing. In this setting dDAVP did not produce as great a fall in plasma osmolality nor did it increase UPGEV. These data indicate that renal prostaglandin synthesis (as determined by UPGEV) is increased transiently by an acute water load; dDAVP given during continued water ingestion results in a fall in plasma osmolality and increased PGE excretion; however, dDAVP does not increase UPGEV during normal hydration; and UPGEV is independent of changes in urine flow. These findings imply that renal prostaglandins may have a functional role in humans to inhibit the hydroosmotic actions of antidiuretic hormone, and thus hasten the excretion of a water load, and to prevent overhydration when inappropriate antidiuresis occurs. However, there is no evidence that the stimulus for prostaglandin production is dDAVP per se.


1988 ◽  
Vol 254 (3) ◽  
pp. R417-R423 ◽  
Author(s):  
B. J. Freund ◽  
J. R. Claybaugh ◽  
G. M. Hashiro ◽  
M. S. Dice

Endurance exercise training alters the regulation of body fluids. To investigate specifics of these alterations, hormonal, electrolyte, and renal responses to water ingestion (1% of lean body wt) were studied in six moderately trained (T) and 6 untrained (UT) male subjects. No differences between groups for base-line hormonal, electrolyte, or renal measurements were found. After water ingestion, atrial natriuretic factor remained unaltered in both groups. Predrink plasma antidiuretic hormone (ADH) levels of 0.51 +/- (SE) 0.19 (UT) and 0.47 +/- 0.07 microU/ml (T) remained unchanged in the T group but were reduced from min 9 through 90 in the UT group. At 30 min postdrink, UT subjects had lower ADH values than T subjects (0.18 +/- 0.02 vs. 0.33 +/- 0.05 microU/ml), while plasma osmolality was similarly reduced by approximately 3 mosmol/kg in both groups. Urine flow rates increased in both groups from similar values of 0.85 +/- 0.24 (UT) and 0.67 +/- 0.11 ml/min (T) to peak flows of 4.6 +/- 1.6 for UT and 2.7 +/- 1.1 ml/min (T) to peak T, P less than or equal to 0.05) at 60 min postdrink. Urine osmolality was reduced from similar values of 809.1 +/- 62.1 and 867.0 +/- 56.1 mosmol/kg to values of 248.8 +/- 87.6 and 469 +/- 146.1 mosmol/kg for UT and T, respectively (UT vs. T, P less than 0.05), at 60 min. Reduced ADH before reductions in plasma osmolality in the UT but not the T subjects suggests that T subjects have a reduced oropharyngeal inhibition of ADH.(ABSTRACT TRUNCATED AT 250 WORDS)


1978 ◽  
Vol 40 (3) ◽  
pp. 583-589 ◽  
Author(s):  
K. Y. Mustafa ◽  
N. A. Mahmoud ◽  
K. A. Gumaa ◽  
A. M. A. Gader

1. Fluid intake, urine output and evaporative water loss were measured and fluid balance calculated in sixteen subjects for 1 d before Ramadan, during weeks 1–5 of fasting and on the 10th day after the end of Ramadan.2. Plasma osmolality at 06.00 hours, the beginning of the fast, at 18.00 hours, before breaking the fast and at 19.00 hours, 1 h after breaking the fast, and urine osmolality during the day and night were measured before, during and after Ramadan.3. All subjects developed an initial negative fluid balance which was maximum at the beginning of week 3 of fasting and that deficit was compensated for during the later weeks.4. Compensation was brought about by an increase in urine concentration, a decrease in urine volume by day, and salt retention.5. No significant changes were observed in plasma osmolality during the days of fasting and the ‘setting’ of plasma osmolality during Ramadan also was not changed.6. It was concluded that healthy young adults maintain good control of fluid and electroytes during Ramadan.


2019 ◽  
Vol 51 (4) ◽  
pp. 760-772 ◽  
Author(s):  
THOMAS STÖGGL ◽  
OLLI OHTONEN ◽  
MASAKI TAKEDA ◽  
NAOTO MIYAMOTO ◽  
CORY SNYDER ◽  
...  

2004 ◽  
Vol 38 (4) ◽  
pp. 506-506
Author(s):  
P Blackman

2015 ◽  
Vol 41 (3) ◽  
pp. 248-256 ◽  
Author(s):  
Niek F. Casteleijn ◽  
Debbie Zittema ◽  
Stephan J.L. Bakker ◽  
Wendy E. Boertien ◽  
Carlo A. Gaillard ◽  
...  

Background: Vasopressin plays an essential role in osmoregulation, but has deleterious effects in patients with ADPKD. Increased water intake to suppress vasopressin activity has been suggested as a potential renoprotective strategy. This study investigated whether urine and plasma osmolality can be used as reflection of vasopressin activity in ADPKD patients. Methods: We measured urine and plasma osmolality, plasma copeptin concentration, total kidney volume (TKV, by MRI) and GFR (125I-iothalamate). In addition, change in estimated GFR (eGFR) during follow-up was assessed. Results: Ninety-four patients with ADPKD were included (56 males, age 40 ± 10, mGFR 77 ± 32 ml/min/1.73 m2, TKV 1.55 (0.99-2.40) l. Urine osmolality, plasma osmolality and copeptin concentration were 420 ± 195, 289 ± 7 mOsmol/l and 7.3 (3.2-14.6) pmol/l, respectively. Plasma osmolality was associated with copeptin concentration (R = 0.54, p < 0.001), whereas urine osmolality was not (p = 0.4). In addition, urine osmolality was not associated with TKV (p = 0.3), in contrast to plasma osmolality (R = 0.52, p < 0.001) and copeptin concentration (R = 0.61, p < 0.001). Fifty-five patients were followed for 2.8 ± 0.8 years. Baseline plasma and urine osmolality were not associated with change in eGFR (p = 0.6 and p = 0.3, respectively), whereas baseline copeptin concentration did show an association with change in eGFR, in a crude analysis (St. β = -0.41, p = 0.003) and also after adjustment for age, sex and TKV (St. β = -0.23, p = 0.05). Conclusions: These data suggest that neither urine nor plasma osmolality are valid measures to identify ADPKD patients that may benefit from increasing water intake. Copeptin appears a better alternative for this purpose.


Author(s):  
Jinny Jeffery ◽  
Ruth M Ayling ◽  
Richard J S McGonigle

Hypernatraemia over 160 mmol/L is considered to be severe. This case reports a patient who developed extreme hypernatraemia with a serum sodium concentration of 196 mmol/L. The patient was known to have chronic renal impairment and was admitted with acute deterioration of renal function secondary to dehydration. This was considered to be secondary to poor oral fluid intake (related to depression) and lithium-induced nephrogenic diabetes insipidus with salt-losing nephropathy. The patient had a high urinary sodium excretion but was also in a pure water losing state as evidenced by an inappropriately low urine osmolality for the plasma osmolality and was successfully treated with hypotonic intravenous fluid and desmopressin.


Sensors ◽  
2021 ◽  
Vol 21 (7) ◽  
pp. 2535
Author(s):  
Thomas Stöggl ◽  
Dennis-Peter Born

The aims of the study were to assess the robustness and non-reactiveness of wearable near-infrared spectroscopy (NIRS) technology to monitor exercise intensity during a real race scenario, and to compare oxygenation between muscle groups important for cross-country skiing (XCS). In a single-case study, one former elite XCS (age: 39 years, peak oxygen uptake: 65.6 mL/kg/min) was equipped with four NIRS devices, a high-precision global navigation satellite system (GNSS), and a heart rate (HR) monitor during the Vasaloppet long-distance XCS race. All data were normalized to peak values measured during incremental laboratory roller skiing tests two weeks before the race. HR reflected changes in terrain and intensity, but showed a constant decrease of 0.098 beats per minute from start to finish. Triceps brachii (TRI) muscle oxygen saturation (SmO2) showed an interchangeable pattern with HR and seems to be less affected by drift across the competition (0.027% drop per minute). Additionally, TRI and vastus lateralis (VL) SmO2 revealed specific loading and unloading pattern of XCS in uphill and downhill sections, while rectus abdominus (RA) SmO2 (0.111% drop per minute) reflected fatigue patterns occurring during the race. In conclusion, the present preliminary study shows that NIRS provides a robust and non-reactive method to monitor exercise intensity and fatigue mechanisms when applied in an outdoor real race scenario. As local exercise intensity differed between muscle groups and central exercise intensity (i.e., HR) during whole-body endurance exercise such as XCS, NIRS data measured at various major muscle groups may be used for a more detailed analysis of kinetics of muscle activation and compare involvement of upper body and leg muscles. As TRI SmO2 seemed to be unaffected by central fatigue mechanisms, it may provide an alternative method to HR and GNSS data to monitor exercise intensity.


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