The Energetics of Semicontact 3 × 2-min Amateur Boxing

2014 ◽  
Vol 9 (2) ◽  
pp. 233-239 ◽  
Author(s):  
Philip Davis ◽  
Renate M. Leithäuser ◽  
Ralph Beneke
Keyword(s):  
Energy Expenditure ◽  
Metabolic Cost ◽  
High Energy ◽  
Metabolic Energy ◽  
High Energy Phosphates ◽  
High Energy Phosphate ◽  
Video Footage ◽  
Amateur Boxing ◽  
Phosphate System ◽  
Respiratory Gases

The energy expenditure of amateur boxing is unknown.Purpose:Total metabolic cost (Wtot) as an aggregate of aerobic (Waer), anaerobic lactic (W[lactate]), and anaerobic alactic (WPCr) energy of a 3 × 2-min semicontact amateur boxing bout was analyzed.Methods:Ten boxers (mean ± SD [lower/upper 95% confidence intervals]) age 23.7 ± 4.1 (20.8/26.6) y, height 180.2 ± 7.0 (175.2/185.2) cm, body mass 70.6 ± 5.7 (66.5/74.7) kg performed a semicontact bout against handheld pads created from previously analyzed video footage of competitive bouts. Net metabolic energy was calculated using respiratory gases and blood [lactate].Results:Waer, 526.0 ± 57.1 (485.1/566.9) kJ, was higher (P < .001) than WPCr, 58.1 ± 13.6 (48.4/67.8) kJ. W[lactate], 26.2 ± 7.1 (21.1/31.3) kJ, was lower (P < .001) than Waer and WPCr. An ~70-kJ fraction of the aerobic energy expenditure reflects rephosphorylation of high-energy phosphates during the breaks between rounds, which elevated Wtot to ~680 kJ with relative contributions of 77% Waer, 19% WPCr, and 4% W[lactate].Conclusions:The results indicate that the metabolic profile of amateur boxing is predominantly aerobic. They also highlight the importance of a highly developed aerobic capacity as a prerequisite of a high activity rate during rounds and recovery of the high-energy phosphate system during breaks as interrelated requirements of successful boxing.

Responses of beta-adrenoceptor in rat soleus to phosphorus compound levels and/or unloading

1994 ◽  
Vol 266 (5) ◽  
pp. C1257-C1262 ◽  
Author(s):  
Y. Ohira ◽  
K. Saito ◽  
T. Wakatsuki ◽  
W. Yasui ◽  
T. Suetsugu ◽  
...  
Keyword(s):  
Contractile Activity ◽  
Creatine Supplementation ◽  
High Energy ◽  
Hindlimb Suspension ◽  
Phosphorus Compounds ◽  
High Energy Phosphates ◽  
High Energy Phosphate ◽  
Gravitational Unloading ◽  
Beta Adrenoceptor ◽  
Muscle Contractile

Responses of beta-adrenoceptor (beta-AR) in rat soleus to gravitational unloading and/or changes in the levels of phosphorus compounds by feeding either creatine or its analogue beta-guanidinopropionic acid (beta-GPA) were studied. A decrease in the density of beta-AR (about -35%) was induced by 10 days of hindlimb suspension, but the affinity of the receptor was unaffected. Suspension unloading tended to increase the levels of adenosine triphosphate and phosphocreatine and decrease inorganic phosphate. Even without unloading, the beta-AR density decreased after an oral creatine supplementation (about -20%), which also tended to elevate the high-energy phosphate levels in muscle. However, an elevation of beta-AR density was induced (about +36%) after chronic depletion of high-energy phosphates by feeding beta-GPA (about +125%). Data suggest that the density of beta-AR in muscle is elevated if the high-energy phosphate contents are chronically decreased and vice versa. However, it may not be directly related to the degree of muscle contractile activity.

Cellular K+ loss and anion efflux during myocardial ischemia and metabolic inhibition

1989 ◽  
Vol 256 (4) ◽  
pp. H1165-H1175 ◽  
Author(s):  
J. N. Weiss ◽  
S. T. Lamp ◽  
K. I. Shine
Keyword(s):  
Inorganic Phosphate ◽  
Lactate Production ◽  
Selective Inhibition ◽  
High Energy ◽  
Metabolic Inhibitors ◽  
Charge Movement ◽  
High Energy Phosphates ◽  
High Energy Phosphate ◽  
Myocardial Hypoxia ◽  
Inhibition Of Glycolysis

It has been suggested that increased K+ efflux during myocardial hypoxia and ischemia may result from efflux of intracellularly generated anions such as lactate and inorganic phosphate (Pi) as a mechanism of balancing transsarcolemmal charge movement. To investigate this hypothesis cellular K+ loss using 42K+ and K+-sensitive electrodes, intracellular potential, venous lactate and Pi, and tissue lactate and high-energy phosphates were measured in isolated arterially perfused rabbit interventricular septa during exposure to metabolic inhibitors, hypoxia, and ischemia. Selective inhibition of glycolysis caused a marked increase in K+ efflux despite a fall in lactate production and maintenance of normal cellular high-energy phosphate content. During ischemia and hypoxia net loss of lactate and Pi exceeded K+ loss by a factor of 2-6. However, removal of glucose prior to ischemia or during hypoxia increased K+ loss but reduced lactate loss without affecting Pi loss. During hypoxia, 30 mM exogenous lactate did not alter K+ loss in a manner consistent with changes in passive electrodiffusion of lactate ion. These findings inhibition which is not related to anion efflux assumes greater importance under conditions in which glycolysis is inhibited, e.g., ischemia. Under conditions in which glycolysis is not inhibited, e.g., hypoxia, K+ efflux does not parallel passive electrodiffusion of lactate ions. However, this finding does not exclude the possibility that K+ loss could be coupled to carrier-mediated lactate ion efflux.

Effect of hypoxia on myocardial high-energy phosphates in the neonatal mammalian heart

1978 ◽  
Vol 235 (5) ◽  
pp. H475-H481 ◽  
Author(s):  
J. M. Jarmakani ◽  
T. Nagatomo ◽  
M. Nakazawa ◽  
G. A. Langer
Keyword(s):  
Lactate Production ◽  
Creatine Phosphate ◽  
High Energy ◽  
Adult Rabbit ◽  
High Energy Phosphates ◽  
Mechanical Function ◽  
High Energy Phosphate ◽  
Buffer Solution ◽  
Bicarbonate Buffer ◽  
Atp Concentration

The effect of hypoxia on myocardial high-energy phosphate content in the newborn, 2-wk-old, and adult rabbit was determined and compared with mechanical function. Studies were done on the ventricular septum arterially perfused with Krebs-Henseleit bicarbonate buffer solution equilibrated with 95% O2 and 5% CO2 (control) or 95% N2 and 5% CO2 (hypoxia) at 60 beats/min and 27 degrees C. In the adult, ATP concentration decreased to 68%, 56%, and 39% of control after 2, 30, and 60 min of hypoxia, respectively. After 30 min of hypoxia, ATP concentration was not different from control in the newborn but decreased to 82% of control in the 2-wk-old. After 2 min of hypoxia, creatine phosphate concentration decreased to 55% and 10% of control in the newborn and adult rabbit, respectively. Lactate production increased significantly during hypoxia and was greater in the newborn than in the adult. The data indicate that the newborn rabbit is capable of maintaining glycolysis and normal levels of myocardial ATP during hypoxia, which ensures normal myocardial mechanical function for longer periods than in the adult.

Low sodium attenuation of the Ca2+ paradox in the newborn rabbit myocardium

1985 ◽  
Vol 248 (3) ◽  
pp. H345-H349
Author(s):  
S. Uemura ◽  
H. Young ◽  
S. Matsuoka ◽  
J. M. Jarmakani
Keyword(s):  
Rabbit Heart ◽  
High Energy ◽  
Adult Rabbit ◽  
High Energy Phosphates ◽  
Mechanical Function ◽  
High Energy Phosphate ◽  
Newborn Rabbit ◽  
Low Sodium ◽  
Resting Tension ◽  
Rabbit Myocardium

The effect of low sodium (Na 24 mM) perfusate during Ca2+ depletion on mechanical function, tissue high-energy phosphate, creatine kinase (CK) release, and tissue potassium was studied in the arterially perfused newborn and adult rabbit heart. During Ca2+ depletion, the time for DT and +dT/dtmax to decline to half-maximal value in newborn muscles perfused with low Na (46 +/- 3 S) was significantly (P less than 0.05) longer than the value obtained with normal Na (14 +/- 1 S). Similar values were obtained in the adult. During Ca2+ repletion, the increase in resting tension and CK release was attenuated in the low Na groups, and the values in the newborn were significantly less than in the adult. The recovery of +dT/dtmax and tissue high-energy phosphates in the low Na groups were significantly greater than in the normal Na groups, and the values in the newborn were significantly greater than in the adult. These data suggest that low Na during the Ca2+-free period delays both cellular Ca2+ depletion during the Ca2+-free period and Ca2+ influx during Ca2+ repletion. This effect in the newborn is greater than in the adult and might be explained by Na+-Ca2+ exchange.

scholarly journals Human walking in the real world: Interactions between terrain type, gait parameters, and energy expenditure

2019 ◽  
Author(s):  
DB Kowalsky ◽  
JR Rebula ◽  
LV Ojeda ◽  
PG Adamczyk ◽  
AD Kuo
Keyword(s):  
Energy Expenditure ◽  
Real World ◽  
Metabolic Cost ◽  
Metabolic Energy ◽  
Least Squares Regression ◽  
The Real ◽  
Terrain Type ◽  
Gait Parameters ◽  
Surface Irregularities ◽  
Metabolic Energy Expenditure

AbstractHumans often traverse real-world environments with a variety of surface irregularities and inconsistencies, which can disrupt steady gait and require additional effort. Such effects have, however, scarcely been demonstrated quantitatively, because few laboratory biomechanical measures apply outdoors. Walking can nevertheless be quantified by other means. In particular, the foot’s trajectory in space can be reconstructed from foot-mounted inertial measurement units (IMUs), to yield measures of stride and associated variabilities. But it remains unknown whether such measures are related to metabolic energy expenditure. We therefore quantified the effect of five different outdoor terrains on foot motion (from IMUs) and net metabolic rate (from oxygen consumption) in healthy adults (N = 10; walking at 1.25 m/s). Energy expenditure increased significantly (P < 0.05) in the order Sidewalk, Dirt, Gravel, Grass, and Woodchips, with Woodchips about 27% costlier than Sidewalk. Terrain type also affected measures, particularly stride variability and virtual foot clearance (swing foot’s lowest height above consecutive footfalls). In combination, such measures can also roughly predict metabolic cost (adjusted R2 = 0.52, partial least squares regression), and even discriminate between terrain types (10% reclassification error). Body-worn sensors can characterize how uneven terrain affects gait, gait variability, and metabolic cost in the real world.

Effect of hyperventilation on dynamics of cerebral energy metabolism

1975 ◽  
Vol 228 (6) ◽  
pp. 1862-1867 ◽  
Author(s):  
K Kogure ◽  
R Busto ◽  
A Matsumoto ◽  
P Scheinberg ◽  
OM Reinmuth
Keyword(s):  
Energy Metabolism ◽  
Closed System ◽  
Energy Production ◽  
Energy Charge ◽  
High Energy ◽  
Utilization Rate ◽  
High Energy Phosphates ◽  
High Energy Phosphate ◽  
Cerebral Energy Metabolism ◽  
Extreme Degree

Hypocapnia of moderate and extreme degree (Paco2 21.1 and 13.5 torr, respectively)was induced by hyperventilation in rats subjected to the closed system of Lowry inorder to evaluate the effects on utilization rate of cerebral energy metabolites. The tissue levels of high-energy phosphates and calculated intracellular pH did not change, whereas glucose, pyruvate, and lactate increased significantly. The La/Pyratio and NADH/NAD-+ RATIO BOTH INCREASED IN PROPORTION TO THE DEGREE OF HYPOCAPNIA.Utilization rates of glucose, glycogen, and ATP were all significantly reduced by hypocapnia, whereas the utilization rate of phosphocreatine was increased. The rate oftotal high-energy phosphate use was also diminished in proportion to the degree of hypocapnia. The constant value of the energy charge (0.94 plus or minus 0.01) indicates that the energy production rate might also be reduced by hyperventilation; thus the intermediate metabolics and substrates increased. It is concluded that extreme hypocapnia reduces the rate of cerebral energy metabolism significantly.

High-energy phosphate compounds of rat diaphragm and skeletal muscle fibers

1961 ◽  
Vol 200 (1) ◽  
pp. 182-186 ◽  
Author(s):  
Ruth D. Peterson ◽  
Clarissa H. Beatty ◽  
Rose M. Bocek
Keyword(s):  
Uric Acid ◽  
Absorption Maximum ◽  
Room Temperature ◽  
Creatine Phosphate ◽  
High Energy ◽  
High Energy Phosphates ◽  
Rat Diaphragm ◽  
High Energy Phosphate ◽  
Atp Levels

The metabolism of high-energy phosphates in a muscle fiber preparation and diaphragm has been investigated. During dissection the creatine phosphate (CrP) level of fibers decreased but was reconstituted during soaking to 61% of the in situ value and remained uncharged during incubation. Dissection and soaking did not affect the adenosinetriphosphate + adenosinediphosphate (ATP + ADP) levels but incubation caused small decreases. Similar decreases in CrP and ATP levels of diaphragm occurred during incubation. The decreases in the ATP levels in fibers and diaphragm correlated with decreases in adenine absorption. A concomitant shift occurred in the absorption peak of fiber media toward the absorption maximum of hypoxanthine. In contrast, the curves for diaphragm media showed a progressive shift toward the absorption maximum for uric acid. Uricase analyses demonstrated uric acid in diaphragm media. The mesothelial covering of the diaphragm was shown to have a separate and distinct metabolism which converts hypoxanthine to uric acid. Soaking the fibers in iced buffer instead of buffer at room temperature decreased the CrP levels after incubation, ATP values were unaffected.

Exercise hyperthermia as a factor limiting physical performance: temperature effect on muscle metabolism

1985 ◽  
Vol 59 (3) ◽  
pp. 766-773 ◽  
Author(s):  
S. Kozlowski ◽  
Z. Brzezinska ◽  
B. Kruk ◽  
H. Kaciuba-Uscilko ◽  
J. E. Greenleaf ◽  
...  
Keyword(s):  
Adverse Effect ◽  
Muscle Metabolism ◽  
Creatine Phosphate ◽  
High Energy ◽  
High Energy Phosphates ◽  
Glycogen Depletion ◽  
Heavy Exercise ◽  
High Energy Phosphate ◽  
Glycolytic Intermediates ◽  
Temperature Equilibrium

The muscle contents of high-energy phosphates and their derivatives [ATP, ADP, AMP, creatine phosphate (CrP), and creatine], glycogen, some glycolytic intermediates, pyruvate, and lactate were compared in 11 dogs performing prolonged heavy exercise until exhaustion (at ambient temperature 20.0 +/- 1.0 degrees C) without and with trunk cooling using ice packs. Without cooling, dogs were able to run for 57 +/- 8 min, and their rectal (Tre) and muscle (Tm) temperatures increased to 41.8 +/- 0.2 and 43.0 +/- 0.2 degrees C, respectively. Compared with noncooling, duration of exercise with cooling was longer by approximately 45% while Tre and Tm at the time corresponding to the end of exercise without cooling were lower by 1.1 +/- 0.2 and 1.2 +/- 0.2 degrees C, respectively. The muscle contents of high-energy phosphates (ATP + CrP) decreased less, the rate of glycogen depletion was lower, and the increases in the contents of AMP, pyruvate, and lactate as well as in the muscle-to-blood lactate ratio were smaller. The muscle content of lactate was positively correlated with Tm. The data indicate that with higher body temperature equilibrium between high-energy phosphate breakdown and resynthesis was shifted to the lower values of ATP and CrP and glycolysis was accelerated. The results suggest that hyperthermia developing during prolonged muscular work exerts an adverse effect on muscle metabolism that may be relevant to limitation of endurance.

Bioenergetics of acute vasogenic edema

1980 ◽  
Vol 53 (4) ◽  
pp. 470-476 ◽  
Author(s):  
Leslie N. Sutton ◽  
Frank Welsh ◽  
Derek A. Bruce
Keyword(s):  
White Matter ◽  
Adenosine Triphosphate ◽  
Vasogenic Edema ◽  
Lactate Concentration ◽  
High Energy ◽  
High Energy Phosphates ◽  
High Energy Phosphate ◽  
Content Type ◽  
Cold Lesion ◽  
Fine Print

✓ The bioenergetic mechanisms of vasogenic edema were studied by measuring concentrations of adenosine triphosphate (ATP), phosphocreatine (CrP), and lactate in rapidly frozen edematous white matter in cats. When edema was produced using a cold lesion, it was found that both ATP and CrP were reduced to one-half of control values, and that lactate was elevated. When a correction was applied for dilution, however, it was found that high-energy phosphates were equal to control values, and that lactate was even more significantly elevated. This pattern contrasted with that seen in white-matter ischemia, in which CrP is depressed out of proportion to ATP. Finally, it was found that the white-matter lactate concentration in the plasma infusion model of edema was increased. It is concluded that vasogenic edema induces an increase in lactate, but does not deplete high-energy phosphate compounds in affected white matter.

Abstract 1571: Hibernating Myocardium has Reduced High Energy Phosphate Levels and a Preconditioning-Like Effect with Slower ATP Depletion in Response to Acute Ischemia

Circulation ◽  
2007 ◽  
Vol 116 (suppl_16) ◽  
Author(s):  
Qingsong Hu ◽  
Gen Suzuk ◽  
John M Canty ◽  
James A Fallavollita
Keyword(s):  
High Energy ◽  
Atp Depletion ◽  
Energy Utilization ◽  
Hibernating Myocardium ◽  
Wall Thickening ◽  
Acute Ischemia ◽  
High Energy Phosphates ◽  
High Energy Phosphate ◽  
Chronic Coronary Artery Disease ◽  
Atp Levels

Background. Pigs with a chronic LAD stenosis develop hibernating myocardium with contractile dysfunction and reduced resting flow. We hypothesized that this reduced energy utilization preserves ATP and protects the heart from irreversible injury during acute ischemia. Methods. Pigs with hibernating myocardium were studied 3-months after instrumentation with a 1.5 mm proximal LAD stenosis (n=7). Hibernating myocardium was confirmed by reduced LAD wall thickening (2.4±0.2 vs.6.1±0.6 mm in remote, p<0.05) and reduced resting flow (0.95±0.15 vs. 1.66±0.29 ml/min/g in remote, p<0.05) without infarction. Subendocardial samples were rapidly excised from propofol anesthetized pigs and serial depletion of high energy phosphates quantified by HPLC (in μmol/g dry weight) during simulated total ischemia in vitro (37°C). Results. At Baseline, ATP and ADP were significantly reduced in the hibernating LAD region in comparison to controls (n=8, Table ), with preserved CP/ATP and ATP/ADP ratios. During simulated ischemia, hibernating myocardium displayed a markedly reduced rate of ATP depletion (ΔATP), with ATP levels at 20 min significantly higher than control (Table ). Higher ATP levels were maintained throughout 80 min of ischemia. Interestingly, identical preservation of high energy phosphates occurred in the remote normally perfused region of hearts with hibernating myocardium (Table ). Conclusion. These data indicate that there is a balanced reduction in high energy phosphate levels in hibernating myocardium with chronic protection from ischemia manifested by a slower rate of ATP depletion during acute ischemia. This preconditioning-like effect is global suggesting that it arises from stimuli that are not directly related to ischemia. This raises the possibility that stretch from cyclical elevations in LV filling pressure or a circulating factor released from the heart in response to ischemia can protect the heart in chronic coronary artery disease.

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