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    <title><![CDATA[Medicine & Science in Sports & Exercise - Current Issue]]></title>
    <link>http://journals.lww.com/acsm-msse/pages/currenttoc.aspx</link>
    <description />
    <language>en-us</language>
    <lastBuildDate>Sun, 22 Nov 2009 04:45:29 -0600</lastBuildDate>
    <generator>Wolters Kluwer Health RSS Generator</generator>
    <image>
      <url>http://images.journals.lww.com/acsm-msse/XLargeThumb.00005768-200912000-00000.CV.jpeg</url>
      <title><![CDATA[Medicine & Science in Sports & Exercise - Current Issue]]></title>
      <link>http://journals.lww.com/acsm-msse/pages/currenttoc.aspx</link>
    </image>
    <item>
      <link>http://journals.lww.com/acsm-msse/Fulltext/2009/12000/Metabolic_Syndrome_and_Insulin_Resistance_in.1.aspx</link>
      <author>BORCHERS, JAMES R.; CLEM, KELLEY L.; HABASH, DIANE L.; NAGARAJA, HAIKADY N.; STOKLEY, LISA M.; BEST, THOMAS M.</author>
      <category>Clinical Sciences</category>
      <title><![CDATA[Metabolic Syndrome and Insulin Resistance in Division 1 Collegiate Football Players]]></title>
      <description><![CDATA[Purpose: To estimate the prevalence of metabolic syndrome and insulin resistance in a cohort of Division 1 collegiate football players.
Methods: Ninety football players were evaluated in a cross-sectional study to estimate the prevalence of metabolic syndrome, insulin resistance, and associated risk factors. Obesity was defined as a body fat >=25% determined by BOD POD measurements. The National Cholesterol Education Program Adult Treatment Panel III criteria were used to estimate prevalence of metabolic syndrome. Quantitative insulin sensitivity check index calculations were performed to estimate prevalence of insulin resistance. Linear regression techniques were used to determine association between body fat percentage and other measured continuous parameters. Fisher exact test was used to determine association between nominal variables, and one-way ANOVA compared the three groups defined by position.
Results: Summary measures showed a small prevalence of abnormal individual measurements. There was an association between body fat percentage and most evaluated parameters (P < 0.05). The prevalence of obesity, insulin resistance, and metabolic syndrome was 21%, 21%, and 9%, respectively. Obesity is closely associated with metabolic syndrome (P < 0.0001) and insulin resistance (P < 0.0001) in this population. All subjects with metabolic syndrome were obese, and the odds for insulin resistance in the obese group are 10.6 times the odds for the nonobese group. Linemen (n = 29) had 19 of the 19 obese subjects, 13 of the 19 subjects with insulin resistance, and all subjects with metabolic syndrome.
Conclusions: There is a strong association between obesity and both metabolic syndrome and insulin resistance in Division 1 collegiate football players. Linemen are at significant risk for metabolic syndrome and insulin resistance compared with other positions. This may be predictive of future health problems in Division 1 collegiate football players, especially linemen.
(C)2009The American College of Sports Medicine]]></description>
      <pubDate>12/1/2009 12:00:00 AM</pubDate>
      <guid isPermaLink="false">00005768-200912000-00001</guid>
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    <item>
      <link>http://journals.lww.com/acsm-msse/Fulltext/2009/12000/Postprandial_Oxidative_Stress__Influence_of_Sex.2.aspx</link>
      <author>BLOOMER, RICHARD J.; FEREBEE, DAVID E.; FISHER-WELLMAN, KELSEY H.; QUINDRY, JOHN C.; SCHILLING, BRIAN K.</author>
      <category>Clinical Sciences</category>
      <title><![CDATA[Postprandial Oxidative Stress: Influence of Sex and Exercise Training Status]]></title>
      <description><![CDATA[An individual's sex and exercise training status may influence oxidative stress. No study has compared postprandial oxidative stress in exercise-trained and untrained men and women.
Purpose: To compare oxidative stress biomarkers and triglycerides (TAG) in 16 trained and 16 untrained men and women after ingestion of a high-fat meal.
Methods: Blood samples were collected before, and at 1, 2, 4, and 6 h after intake of a high-fat meal and analyzed for Trolox-equivalent antioxidant capacity (TEAC), malondialdehyde, hydrogen peroxide, xanthine oxidase activity, protein carbonyls (PC), and TAG. Area under the curve was calculated for each variable.
Results: Sex main effects were noted for all variables (P < 0.01), except for PC and TEAC (P > 0.05), with higher values for men compared with women. A training status main effect was noted for TEAC (P = 0.02), with higher values for trained compared with untrained subjects. No interaction effects were noted (P > 0.05). Regression analysis indicated that TAG explained the greatest degree of variability for oxidative stress variables, and premeal TAG best predicted the TAG response to feeding (R2 = 0.50).
Conclusions: With the exception of TEAC, for which higher values were noted for trained compared with untrained subjects, our findings indicate that sex, not exercise training status, influences postprandial oxidative stress. Specifically, women experience a significantly lower oxidative stress response to feeding compared with men. This seems mediated in part by the TAG response to feeding.
(C)2009The American College of Sports Medicine]]></description>
      <pubDate>12/1/2009 12:00:00 AM</pubDate>
      <guid isPermaLink="false">00005768-200912000-00002</guid>
    </item>
    <item>
      <link>http://journals.lww.com/acsm-msse/Fulltext/2009/12000/Metabolic_Myopathies__Functional_Evaluation_by.3.aspx</link>
      <author>GRASSI, BRUNO; PORCELLI, SIMONE; MARZORATI, MAURO; LANFRANCONI, FRANCESCA; VAGO, PAOLA; MARCONI, CLAUDIO; MORANDI, LUCIA</author>
      <category>Clinical Sciences</category>
      <title><![CDATA[Metabolic Myopathies: Functional Evaluation by Analysis of Oxygen Uptake Kinetics]]></title>
      <description><![CDATA[Purpose: The aim was to identify additional noninvasive tools allowing to detect and to quantify the metabolic impairment in patients with mitochondrial myopathies (MM) or McArdle's disease (McA).
Methods: Kinetics of adjustment of pulmonary oxygen uptake (V[spacing dot above]O2 kinetics) during transitions to constant-load moderate-intensity cycle ergometer exercise were determined on 15 MM, 8 McA, 21 patients with signs and/or symptoms of metabolic myopathy but a negative biopsy ("patient controls"; P-CTRL), and 22 healthy untrained controls (CTRL).
Results: V[spacing dot above]O2 kinetics were slower in MM and in McA versus P-CTRL and CTRL, slower in McA versus MM, and not significantly different between P-CTRL and CTRL. The time constants ([tau]) of the monoexponential function describing the V[spacing dot above]O2 kinetics were (X[spacing macron] +/- SE) 59.2 +/- 8.5 s in MM, 87.6 +/- 16.4 s in McA, 36.9 +/- 3.1 s in P-CTRL, and 35.4 +/- 1.9 s in CTRL. In a subgroup of the patients (eight MM and seven McA), [tau] of V[spacing dot above]O2 kinetics were negatively correlated with two variables determined in a previous study (Grassi B, Marzorati M, Lanfranconi F, et al. Impaired oxygen extraction in metabolic myopathies: detection and quantification by near-infrared spectroscopy. Muscle Nerve. 2007;35:510-20): a) a muscle oxygenation index, obtained by near-infrared spectroscopy, estimating the peak capacity of skeletal muscle fractional O2 extraction; and b) V[spacing dot above]O2 peak.
Conclusions: In MM and McA patients, analysis of pulmonary V[spacing dot above]O2 kinetics during moderate-intensity exercise allows to identify and to quantify, noninvasively, the impairment of skeletal muscle oxidative metabolism. In these patients, the slower V[spacing dot above]O2 kinetics can be considered a marker of the impaired exercise tolerance. The present data could be useful for clinicians who need an objective, quantitative, and longitudinal evaluation of the impairment to be used in the follow-up of these patients as well as in the assessment of therapeutic interventions.
(C)2009The American College of Sports Medicine]]></description>
      <pubDate>12/1/2009 12:00:00 AM</pubDate>
      <guid isPermaLink="false">00005768-200912000-00003</guid>
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    <item>
      <link>http://journals.lww.com/acsm-msse/Fulltext/2009/12000/Long_Term_Exercise_Stabilizes_Atherosclerotic.4.aspx</link>
      <author>PELLEGRIN, MAXIME; MIGUET-ALFONSI, CAROLE; BOUZOURENE, KARIMA; AUBERT, JEAN-FRANÇOIS; DECKERT, VALÉRIE; BERTHELOT, ALAIN; MAZZOLAI, LUCIA; LAURANT, PASCAL</author>
      <category>Basic Sciences</category>
      <title><![CDATA[Long-Term Exercise Stabilizes Atherosclerotic Plaque in ApoE Knockout Mice]]></title>
      <description><![CDATA[Purpose: Exercise is known to reduce cardiovascular mortality. However, the precise mechanisms are still unknown. Because atherosclerotic plaque destabilization and rupture leads to dramatic cardiovascular events, stabilization of plaque might be regarded as an important goal of an exercise preventive therapy. The present study examined the plaque-stabilizing effect of long-term exercise in experimental atherosclerosis using apolipoprotein E-deficient mice (ApoE-/-).
Methods: ApoE-/- mice were subjected to 6 months of swimming exercise. A group of sedentary animals were used as controls. Morphometry and characteristics of atherosclerotic plaque stability were assessed in aortic sinus by immunohistochemistry. Aortic levels of total protein kinase Akt (protein kinase B), phosphorylated Akt at Ser473 (p-Akt), total endothelial nitric oxide synthase (eNOS), and phosphorylated eNOS at Ser1177 (p-eNOS) were assessed by Western blotting.
Results: Exercised mice developed a more stable plaque phenotype as shown by decreased macrophage and increased smooth muscle cell content. Protein expressions of Akt, p-Akt, eNOS, and p-eNOS were not modulated by exercise.
Conclusions: Long-term exercise promotes plaque stability in ApoE-/- mice. The Akt-mediated eNOS phosphorylation pathway seems not to be the primary molecular mechanism.
(C)2009The American College of Sports Medicine]]></description>
      <pubDate>12/1/2009 12:00:00 AM</pubDate>
      <guid isPermaLink="false">00005768-200912000-00004</guid>
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    <item>
      <link>http://journals.lww.com/acsm-msse/Fulltext/2009/12000/Similar_Expression_of_Oxidative_Genes_after.5.aspx</link>
      <author>WANG, LI; PSILANDER, NIKLAS; TONKONOGI, MICHAIL; DING, SHUZHE; SAHLIN, KENT</author>
      <category>Basic Sciences</category>
      <title><![CDATA[Similar Expression of Oxidative Genes after Interval and Continuous Exercise]]></title>
      <description><![CDATA[Purpose: There is a debate whether interval or traditional endurance training is the most effective stimulus of mitochondrial biogenesis. Here, we compared the effects of acute interval exercise (IE) or continuous exercise (CE) on the muscle messenger RNA (mRNA) content for several genes involved in mitochondrial biogenesis and lipid metabolism.
Methods: Nine sedentary subjects cycled for 90 min with two protocols: CE (at 67% V[spacing dot above]O2max) and IE (12 s at 120% and 18 s at 20% of V[spacing dot above]O2max). The duration of exercise and work performed with CE and IE was identical. Muscle biopsies were taken before and 3 h after exercise.
Results: There were no significant differences between the two exercise protocols in the increases in V[spacing dot above]O2 and HR, the reduction in muscle glycogen (35%-40% with both protocols) or the changes in blood metabolites (lactate, glucose, and fatty acids). The mRNA content for major regulators of mitochondrial biogenesis [peroxisome proliferator-activated receptor (PPAR) [gamma] coactivator 1[alpha] (PGC-1[alpha]), PGC-1-related coactivator, PPAR/[delta]] and of lipid metabolism [pyruvate dehydrogenase kinase isozyme 4 (PDK4)] increased after exercise, but there was no significant difference between IE and CE. However, the mRNA content for several downstream targets of PGC-1[alpha] increased significantly only after CE, and mRNA content for nuclear respiratory factor 2 was significantly higher after CE (P < 0.025 vs IE).
Conclusions: The present findings demonstrate that, when the duration of exercise and work performed is the same, IE and CE influence the transcription of genes involved in oxidative metabolism in a similar manner.
(C)2009The American College of Sports Medicine]]></description>
      <pubDate>12/1/2009 12:00:00 AM</pubDate>
      <guid isPermaLink="false">00005768-200912000-00005</guid>
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    <item>
      <link>http://journals.lww.com/acsm-msse/Fulltext/2009/12000/Bone_Geometry,_Strength,_and_Muscle_Size_in.6.aspx</link>
      <author>POPP, KRISTIN L.; HUGHES, JULIE M.; SMOCK, AMANDA J.; NOVOTNY, SUSAN A.; STOVITZ, STEVEN D.; KOEHLER, SCOTT M.; PETIT, MOIRA A.</author>
      <category>Basic Sciences</category>
      <title><![CDATA[Bone Geometry, Strength, and Muscle Size in Runners with a History of Stress Fracture]]></title>
      <description><![CDATA[Purpose: Our primary aim was to explore differences in estimates of tibial bone strength, in female runners with and without a history of stress fractures. Our secondary aim was to explore differences in bone geometry, volumetric density, and muscle size that may explain bone strength outcomes.
Methods: A total of 39 competitive distance runners aged 18-35 yr, with (SFX, n = 19) or without (NSFX, n = 20) a history of stress fracture were recruited for this cross-sectional study. Peripheral quantitative computed tomography (XCT 3000; Orthometrix, White Plains, NY) was used to assess volumetric bone mineral density (vBMD, mg[middle dot]mm-3), bone area (ToA, mm2), and estimated compressive bone strength (bone strength index (BSI) = ToA x total volumetric density (ToD2)) at the distal tibia (4%). Total (ToA, mm2) and cortical (CoA, mm2) bone area, cortical vBMD, and estimated bending strength (strength-strain index (SSIp), mm3) were measured at the 15%, 25%, 33%, 45%, 50%, and 66% sites. Muscle cross-sectional area (MCSA) was measured at the 50% and 66% sites.
Results: Participants in the SFX group had significantly smaller (7%-8%) CoA at the 45%, 50%, and 66% sites (P <= 0.05 for all), significantly lower SSIp (9%-10%) at the 50% and 66% sites, and smaller MCSA (7%-8%) at the 66% site. The remaining bone parameters including vBMD were not significantly different between groups. After adjusting for MCSA, there were no differences between groups for any measured bone outcomes.
Conclusions: These findings suggest that cortical bone strength, cortical area, and MCSA are all lower in runners with a history of stress fracture. However, the lower strength was appropriate for the smaller muscle size, suggesting that interventions to reduce stress fracture risk might be aimed at improving muscle size and strength.
(C)2009The American College of Sports Medicine]]></description>
      <pubDate>12/1/2009 12:00:00 AM</pubDate>
      <guid isPermaLink="false">00005768-200912000-00006</guid>
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    <item>
      <link>http://journals.lww.com/acsm-msse/Fulltext/2009/12000/Fuel_Selection_during_Prolonged_Arm_and_Leg.7.aspx</link>
      <author>TREMBLAY, JONATHAN H.; PÉRONNET, FRANÇOIS; LAVOIE, CAROLE; MASSICOTTE, DENIS</author>
      <category>Basic Sciences</category>
      <title><![CDATA[Fuel Selection during Prolonged Arm and Leg Exercise with 13C-Glucose Ingestion]]></title>
      <description><![CDATA[Purpose: To compare fuel selection during prolonged arm (AE) and leg exercise (LE) with water or glucose ingestion.
Methods: Ten subjects (V[spacing dot above]O2max: 4.77 +/- 0.20 and 3.36 +/- 0.15 L[middle dot]min-1 for LE and AE, respectively) completed 120 min of LE and AE at 50% of the mode-specific maximal power output (353 +/- 18 and 160 +/- 9 W, respectively) with ingestion of water (20 mL[middle dot]kg-1) or 13C-glucose (2 g[middle dot]kg-1). Substrate oxidation was measured using indirect respiratory calorimetry corrected for urea excretion and 13CO2 production at the mouth.
Results: The contribution of protein oxidation to the energy yield (%En) was higher during AE than LE (~8% vs ~4%) because of the lower energy expenditure and was not significantly modified with glucose ingestion. With water ingestion, the %En from CHO oxidation was not significantly different during LE and AE (64 +/- 2% and 66 +/- 2%, respectively). Glucose ingestion significantly increased the %En from total CHO oxidation during AE (78 +/- 3%) but not during LE (71 +/- 2%). Exogenous glucose oxidation was not significantly different in AE and LE (56 +/- 4 and 65 +/- 3 g, respectively), but the %En from exogenous glucose was higher during AE than LE (30 +/- 1% and 24 +/- 1%) because of the lower energy expenditure. When glucose was ingested, the %En from endogenous CHO oxidation was significantly reduced during both AE (66 +/- 2% to 48 +/- 3%) and LE (64 +/- 2% to 47 +/- 3%) and was not significantly different in the two modes of exercise.
Conclusions: The difference in fuel selection between AE and LE when water was ingested was modest with a slightly higher reliance on CHO oxidation during AE. The amount of exogenous glucose oxidized was lower but its %En was higher during AE because of the lower energy expenditure.
(C)2009The American College of Sports Medicine]]></description>
      <pubDate>12/1/2009 12:00:00 AM</pubDate>
      <guid isPermaLink="false">00005768-200912000-00007</guid>
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    <item>
      <link>http://journals.lww.com/acsm-msse/Fulltext/2009/12000/Muscle_Metabolism_during_Exercise_with.8.aspx</link>
      <author>CERMAK, NAOMI M.; SOLHEIM, AMY S.; GARDNER, MELANIE S.; TARNOPOLSKY, MARK A.; GIBALA, MARTIN J.</author>
      <category>Basic Sciences</category>
      <title><![CDATA[Muscle Metabolism during Exercise with Carbohydrate or Protein-Carbohydrate Ingestion]]></title>
      <description><![CDATA[Introduction: Ingesting protein (PRO) with CHO during prolonged exercise is purported to improve performance compared with CHO alone by altering the regulation of skeletal muscle energy provision. However, no study has directly investigated this issue. We tested the hypothesis that compared with CHO alone, coingestion of PRO would alter markers of metabolic control, including the magnitude of glycogen use and the net expansion of the tricarboxylic acid cycle intermediate pool, which has been linked to the capacity for oxidative energy delivery.
Methods: Eight trained men (mean +/- SE: age = 29 +/- 2 yr; V[spacing dot above]O2peak = 55 +/- 2 mL[middle dot]kg-1[middle dot]min-1) cycled at 69% +/- 1% V[spacing dot above]O2peak for 90 min on two occasions, and biopsy samples (vastus lateralis) were obtained before and after exercise. In a randomized, double-blind manner, subjects ingested one of two drinks during exercise that contained either 6% CHO or 6% CHO + 2% PRO (CHO + PRO) at a rate of 1 L[middle dot]h-1 to deliver 60 g[middle dot]h-1 CHO +/- 20 g[middle dot]h-1 PRO.
Results: CHO + PRO ingestion increased the plasma concentration of branched chain (561 +/- 46 vs 301 +/- 32 [mu]mol[middle dot]L-1) and essential amino acids (1071 +/- 98 vs 670 +/- 71 [mu]mol[middle dot]L-1) after exercise versus CHO (both P values <=0.05). However, net muscle glycogen use (CHO + PRO = 223 +/- 31 vs CHO = 185 +/- 38 mmol[middle dot]kg-1 dry weight) and tricarboxylic acid cycle intermediate expansion (CHO + PRO = 2.3 +/- 0.7 vs CHO = 2.1 +/- 0.2 mmol[middle dot]kg-1 dry weight) were similar between trials. Blood creatine kinase activity and 20-km time trial performance measured approximately 24 h after the first exercise bout were not different between treatments.
Conclusion: When trained men ingest CHO at a rate on the upper end of the range generally recommended to improve endurance performance, coingestion of PRO does not alter specific markers proposed to reflect an enhanced capacity for skeletal muscle energy delivery.
(C)2009The American College of Sports Medicine]]></description>
      <pubDate>12/1/2009 12:00:00 AM</pubDate>
      <guid isPermaLink="false">00005768-200912000-00008</guid>
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      <link>http://journals.lww.com/acsm-msse/Fulltext/2009/12000/WISE_2005__Exercise_and_Nutrition_Countermeasures.9.aspx</link>
      <author>SCHNEIDER, SUZANNE M.; LEE, STUART M. C.; MACIAS, BRANDON R.; WATENPAUGH, DONALD E.; HARGENS, ALAN R.</author>
      <category>Basic Sciences</category>
      <title><![CDATA[WISE-2005: Exercise and Nutrition Countermeasures for Upright V[spacing dot above]O2pk during Bed Rest]]></title>
      <description><![CDATA[Purpose: Exercise prescriptions for spaceflight include aerobic and resistive countermeasures, yet few studies have evaluated their combined effects on exercise responses after real or simulated microgravity. We hypothesized that upright aerobic capacity (V[spacing dot above]O2pk) is protected during a 60-d bed rest (BR) in which intermittent (40%-80% pre-BR V[spacing dot above]O2pk) aerobic exercise (supine treadmill exercise against lower body negative pressure) was performed 2-4 d[middle dot]wk-1 and resistive exercise (inertial flywheel exercises) was performed 2-3 d[middle dot]wk-1. Further, we hypothesized that ingestion of an amino acid supplement that was shown previously to counteract muscle atrophy, would reduce the decline in V[spacing dot above]O2pk in nonexercising subjects during BR.
Methods: Twenty-four healthy women (8 nonexercise controls (CON), 8 exercisers (EX), and 8 nonexercisers with nutritional supplementation (NUT)) underwent a 20-d ambulatory baseline period, 60 d of 6[degrees] head-down tilt BR, and 21 d of ambulatory recovery. V[spacing dot above]O2pk was measured pre-BR and on the third day of recovery from BR (R3).
Results: In the EX group, V[spacing dot above]O2pk (mean +/- SE) was not different from pre-BR (-3.3 +/- 1.2%) on R3, although it decreased significantly in the CON (-21.2 +/- 2.1%) and NUT (-25.6 +/- 1.6%) groups.
Conclusions: These results indicate that alternating aerobic and resistive exercise on most days during prolonged microgravity simulated by BR is sufficient to preserve or allow quick recovery of upright aerobic capacity in women but that a nutritional supplementation alone is not effective.
(C)2009The American College of Sports Medicine]]></description>
      <pubDate>12/1/2009 12:00:00 AM</pubDate>
      <guid isPermaLink="false">00005768-200912000-00009</guid>
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      <link>http://journals.lww.com/acsm-msse/Fulltext/2009/12000/Effects_of_Stride_Length_and_Running_Mileage_on_a.10.aspx</link>
      <author>EDWARDS, W. BRENT; TAYLOR, DAVID; RUDOLPHI, THOMAS J.; GILLETTE, JASON C.; DERRICK, TIMOTHY R.</author>
      <category>Applied Sciences</category>
      <title><![CDATA[Effects of Stride Length and Running Mileage on a Probabilistic Stress Fracture Model]]></title>
      <description><![CDATA[The fatigue life of bone is inversely related to strain magnitude. Decreasing stride length is a potential mechanism of strain reduction during running. If stride length is decreased, the number of loading cycles will increase for a given mileage. It is unclear if increased loading cycles are detrimental to skeletal health despite reductions in strain.
Purpose: To determine the effects of stride length and running mileage on the probability of tibial stress fracture.
Methods: Ten male subjects ran overground at their preferred running velocity during two conditions: preferred stride length and 10% reduction in preferred stride length. Force platform and kinematic data were collected concurrently. A combination of experimental and musculoskeletal modeling techniques was used to determine joint contact forces acting on the distal tibia. Peak instantaneous joint contact forces served as inputs to a finite element model to estimate tibial strains during stance. Stress fracture probability for stride length conditions and three running mileages (3, 5, and 7 miles[middle dot]d-1) were determined using a probabilistic model of bone damage, repair, and adaptation. Differences in stress fracture probability were compared between conditions using a 2 x 3 repeated-measures ANOVA.
Results: The main effects of stride length (P = 0.017) and running mileage (P = 0.001) were significant. Reducing stride length decreased the probability of stress fracture by 3% to 6%. Increasing running mileage increased the probability of stress fracture by 4% to 10%.
Conclusions: Results suggest that strain magnitude plays a more important role in stress fracture development than the total number of loading cycles. Runners wishing to decrease their probability for tibial stress fracture may benefit from a 10% reduction in stride length.
(C)2009The American College of Sports Medicine]]></description>
      <pubDate>12/1/2009 12:00:00 AM</pubDate>
      <guid isPermaLink="false">00005768-200912000-00010</guid>
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      <link>http://journals.lww.com/acsm-msse/Fulltext/2009/12000/Critical_Torque,_Estimated_Time_to_Exhaustion,_and.11.aspx</link>
      <author>HENDRIX, C. RUSSELL; HOUSH, TERRY J.; MIELKE, MICHELLE; ZUNIGA, JORGE M.; CAMIC, CLAYTON L.; JOHNSON, GLEN O.; SCHMIDT, RICHARD J.</author>
      <category>Applied Sciences</category>
      <title><![CDATA[Critical Torque, Estimated Time to Exhaustion, and Anaerobic Work Capacity from Linear and Nonlinear Mathematical Models]]></title>
      <description><![CDATA[Theoretically, critical torque (CT) is the maximal isometric torque that can be maintained without fatigue, and anaerobic work capacity (AWC) is the total "isometric work" associated with stored energy sources within the muscle.
Purpose: The purpose of this study was twofold: 1) to determine whether there were differences among the estimates of CT and AWC from linear and nonlinear mathematical models and 2) to compare the estimated time to exhaustion (ETTE) values associated with the CT estimates from the linear and nonlinear mathematical models.
Methods: Nine adult subjects (mean +/- SD age = 21.6 +/- 1.2 yr) performed three or four continuous, fatiguing, isometric muscle actions of the leg extensors at 30%, 45%, 60%, and 75% of maximum voluntary isometric contraction to determine the time to exhaustion (Tlim) values. Five mathematical models (two linear, two nonlinear, and one exponential) were used to estimate CT and AWC (the exponential model did not estimate AWC) from the relationships between "isometric work" or torque and Tlim. Individual torque versus Tlim curves was also generated from the fatiguing isometric muscle actions to calculate the ETTE values.
Results: The exponential model resulted in greater mean CT and lower ETTE values than the other models. There were no significant differences, however, between models for AWC.
Conclusion: Torque-curve analyses indicated that the mean ETTE values range from 7.26 to 16.98 min, and therefore all five CT models (23.0 to 37.0 N[middle dot]m) overestimated the torque levels that could be maintained for an extended period without fatigue.
(C)2009The American College of Sports Medicine]]></description>
      <pubDate>12/1/2009 12:00:00 AM</pubDate>
      <guid isPermaLink="false">00005768-200912000-00011</guid>
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      <link>http://journals.lww.com/acsm-msse/Fulltext/2009/12000/The_Western_States_100_Mile_Endurance_Run_.12.aspx</link>
      <author>HOFFMAN, MARTIN D.; WEGELIN, JACOB A.</author>
      <category>Applied Sciences</category>
      <title><![CDATA[The Western States 100-Mile Endurance Run: Participation and Performance Trends]]></title>
      <description><![CDATA[Purpose: Examine changes in demographics of participants and performance trends at the Western States 100-Mile Endurance Run (WSER) since its inception in 1974.
Methods: Name, age, sex, and finish information was obtained on runners in the WSER from 1974 to 2007. Linear regression analyses, ANOVA, and t-tests were used to examine participation and performance trends.
Results: The mean age of participants increased (P < 0.001) to around 45 yr, with men being an average of 3 yr older (P < 0.001) than women. The increase in average age of starters was accounted for by the growth in participation among women >=40 yr and men >=50 yr, and by the decreasing participation among men <50 yr. Between 1986 and 2007, there was an increasing participation among women to around 20% of all starters. With this came improved (P < 0.01) finish times for the top 5 overall women and the top 5 women in the 30-39 and 40-49 yr age groups, whereas performances among the men did not improve over this time span. Average ages of the top performers increased (P <= 0.002) since 1990 to the upper 30s for both sexes, but the fastest times among men were comparable across the 30-39 and 40-49 yr age groups.
Conclusions: Participation in the WSER has increased among women and older athletes, and the ages of the fastest runners at the WSER have gradually risen to the extent that these runners are older than the ages at which the fastest marathons are run. In contrast to what has been observed for men, finish times have improved for the top women across the last two decades at the WSER.
(C)2009The American College of Sports Medicine]]></description>
      <pubDate>12/1/2009 12:00:00 AM</pubDate>
      <guid isPermaLink="false">00005768-200912000-00012</guid>
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      <link>http://journals.lww.com/acsm-msse/Fulltext/2009/12000/Accelerometer_Prediction_of_Energy_Expenditure_.13.aspx</link>
      <author>HOWE, CHERYL A.; STAUDENMAYER, JOHN W.; FREEDSON, PATTY S.</author>
      <category>Applied Sciences</category>
      <title><![CDATA[Accelerometer Prediction of Energy Expenditure: Vector Magnitude Versus Vertical Axis]]></title>
      <description><![CDATA[It is suggested that triaxial accelerometers (RT3) are superior to single-plane accelerometers for predicting energy expenditure (EE).
Purpose: To compare the RT3 uniaxial and triaxial prediction of activity EE (AEE) during treadmill activities (TM) and activities of daily living (ADL).
Methods: Two hundred and twelve subjects (aged 20-60 yr) completed TM speeds of 1.34, 1.56, and 2.23 m[middle dot]s-1 at 0% and 3% grades, stair ascent/descent, moving a box, and two randomly assigned ADL. Subjects wore a portable indirect calorimeter to measure EE to calculate AEE by subtracting resting metabolic rate. Acceleration counts in the vertical (V), medial-lateral, and anterior-posterior planes were collected in a single RT3 secured to the hip. Predicted AEE (RT3AEE) was estimated from vector magnitude (VM) counts using a proprietary algorithm. A paired t-test compared RT3AEE versus AEE. The relationship among V and VM counts and AEE was examined using linear regression analyses.
Results: RT3 overestimated AEE for all activities combined, overestimated for TM (9.0%), and underestimated for ADL (34.3%; P < 0.001). The R2 values between RT3AEE and AEE for TM and ADL were R2 = 0.78 and R2 = 0.15, respectively. The RT3 underestimated activity with greater upper body movements by 24.4%-64.5% (P < 0.001). V and VM counts were similarly related to AEE (R2 = 0.35) and RT3AEE (R2 = 0.83-0.89).
Conclusions: Although the RT3 did not accurately predict AEE from accelerometer counts, stronger relationships existed between predicted and measured AEE for TM compared with ADL. Compared with V counts, using VM counts to predict AEE did not significantly improve the relationship between counts and AEE. Analytic techniques beyond linear regression with VM as a covariate or with counts from each axis entering the model separately may improve estimates of AEE from triaxial accelerometers.
(C)2009The American College of Sports Medicine]]></description>
      <pubDate>12/1/2009 12:00:00 AM</pubDate>
      <guid isPermaLink="false">00005768-200912000-00013</guid>
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    <item>
      <link>http://journals.lww.com/acsm-msse/Fulltext/2009/12000/Effects_of_Successive_Air_and_Trimix_Dives_on.14.aspx</link>
      <author>MARINOVIC, JASNA; LJUBKOVIC, MARKO; OBAD, ANTE; BAKOVIC, DARIJA; BRESKOVIC, TONI; DUJIC, ZELJKO</author>
      <category>Applied Sciences</category>
      <title><![CDATA[Effects of Successive Air and Trimix Dives on Human Cardiovascular Function]]></title>
      <description><![CDATA[Introduction: The use of trimix (a mixture of oxygen, helium, and nitrogen) has significantly increased among the diver population. However, data indicating how trimix dives at most common depths affect the cardiovascular function are sparse. The purpose of this study was to investigate the cardiovascular effects of trimix dives and compare them with air dives and to determine whether the repetition of dives in successive days affects their extent.
Methods: Nine professional divers performed four dives in consecutive days where the dive depth was progressively increased to the maximum of 55 m. Divers used air in the first dive, nitrox 25 in the second, and trimix 20/30 in the third and fourth dives. Echocardiography was performed before and after each dive.
Results: After each dive, a significantly decreased left ventricular ejection fraction and fractional shortening and an increased end-systolic volume without a change in end-diastolic volume were found, indicating a depressed systolic function of the left side of the heart. Assessment of the ratio between pulmonary artery acceleration time and right ventricular ejection time (used as an indicator of pulmonary artery pressure (PAP)) revealed an increase in PAP after all the dives. No physiologically relevant cumulative effects of the multiple dives or signs of acclimatization were found.
Conclusions: The current study shows that the cardiovascular effects of trimix dives do not differ from those of the dives with compressed air. However, it suggests that even a very safe and conservative trimix diving profile exerts significant cardiovascular effects.
(C)2009The American College of Sports Medicine]]></description>
      <pubDate>12/1/2009 12:00:00 AM</pubDate>
      <guid isPermaLink="false">00005768-200912000-00014</guid>
    </item>
    <item>
      <link>http://journals.lww.com/acsm-msse/Fulltext/2009/12000/A_New_Device_to_Estimate_V_spacing_dot_above_O2.15.aspx</link>
      <author>YAMAZAKI, TOSHIAKI; GEN-NO, HIROKAZU; KAMIJO, YOSHI-ICHIRO; OKAZAKI, KAZUNOBU; MASUKI, SHIZUE; NOSE, HIROSHI</author>
      <category>SPECIAL COMMUNICATIONS: Methodological Advances</category>
      <title><![CDATA[A New Device to Estimate V[spacing dot above]O2 during Incline Walking by Accelerometry and Barometry]]></title>
      <description><![CDATA[Purpose: To examine whether the biased estimation of oxygen consumption rate (V[spacing dot above]O2, mL[middle dot]kg-1[middle dot]min-1) by accelerometry during incline walking can be improved by the addition of altitude changes as measured by barometry.
Methods: We measured V[spacing dot above]O2 by respiratory gas analysis and vector magnitude (VM, G) from triaxial accelerations in 42 healthy people (mean +/- SD age = 63 +/- 7 yr) during graded walking on a treadmill while the incline was varied from -15% to +15%. They walked at subjectively slow, moderate, and fast speeds on level and uphill inclines and, in addition to these, at their fastest speed at 0% incline. They then walked at ~3, 4, and 5 km[middle dot]h-1 on downhill inclines for 3 min each. We determined a regression equation to estimate V[spacing dot above]O2 from VM and theoretical vertical upward (Hu, m[middle dot]min-1) and downward speeds (Hd, m[middle dot]min-1) for the last 1 min of each trial. To validate the precision of the equation, we measured VM and altitude changes with a portable device equipped with a triaxial accelerometer and a barometer in 11 of the 42 subjects walking on an outdoor hill and compared the estimated V[spacing dot above]O2 with the value simultaneously measured by respiratory gas analysis.
Results: V[spacing dot above]O2 above resting was estimated from V[spacing dot above]O2 = 0.044 VM + 1.365 Hu + 0.553 Hd (r = 0.93, P < 0.001) and the estimated V[spacing dot above]O2(y) was almost identical to the measured V[spacing dot above]O2(x) (y = 0.97x, r = 0.88, P < 0.001) with a mean difference of -0.20 +/- 3.47 (mean +/- SD) by Bland-Altman analysis in the range of 2.0-33.0 mL[middle dot]kg-1[middle dot]min-1.
Conclusions: V[spacing dot above]O2 during walking on various inclines can be precisely estimated by using the device equipped with a triaxial accelerometer and a barometer.
(C)2009The American College of Sports Medicine]]></description>
      <pubDate>12/1/2009 12:00:00 AM</pubDate>
      <guid isPermaLink="false">00005768-200912000-00015</guid>
    </item>
    <item>
      <link>http://journals.lww.com/acsm-msse/Fulltext/2009/12000/Drug_Interactions_Analysis_and_Management_2009.16.aspx</link>
      <author>Ranieri, Melissa</author>
      <category>SPECIAL COMMUNICATIONS: Book Reviews</category>
      <title><![CDATA[Drug Interactions Analysis and Management 2009]]></title>
      <description><![CDATA[No abstract available]]></description>
      <pubDate>12/1/2009 12:00:00 AM</pubDate>
      <guid isPermaLink="false">00005768-200912000-00016</guid>
    </item>
    <item>
      <link>http://journals.lww.com/acsm-msse/Fulltext/2009/12000/Fundamentals_of_Cancer_Prevention,_2nd_Edition.17.aspx</link>
      <author>Carr, Vincent</author>
      <category>SPECIAL COMMUNICATIONS: Book Reviews</category>
      <title><![CDATA[Fundamentals of Cancer Prevention, 2nd Edition]]></title>
      <description><![CDATA[No abstract available]]></description>
      <pubDate>12/1/2009 12:00:00 AM</pubDate>
      <guid isPermaLink="false">00005768-200912000-00017</guid>
    </item>
    <item>
      <link>http://pdfs.journals.lww.com/acsm-msse/2009/12000/Author_Listing.18.pdf</link>
      <category>AUTHOR INDEX:  PDF Only</category>
      <title><![CDATA[Author Listing]]></title>
      <description><![CDATA[No abstract available]]></description>
      <pubDate>12/1/2009 12:00:00 AM</pubDate>
      <guid isPermaLink="false">00005768-200912000-00018</guid>
    </item>
    <item>
      <link>http://pdfs.journals.lww.com/acsm-msse/2009/12000/Key_Word_Listing.19.pdf</link>
      <category>KEY WORD INDEX:  PDF Only</category>
      <title><![CDATA[Key Word Listing]]></title>
      <description><![CDATA[No abstract available]]></description>
      <pubDate>12/1/2009 12:00:00 AM</pubDate>
      <guid isPermaLink="false">00005768-200912000-00019</guid>
    </item>
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