Effect of 6-month high-impact step aerobics and resistance training on BMD and tibial bending strength in sedentary premenopausal women.

The rationale of this study was to examine the effectiveness of 6-month high-impact step aerobics (SA) or moderate-intensity resistance training exercise (RT) on bone mineral density (BMD) and bone bending strength in sedentary women. Results show that SA enhanced BMD in the heel, lower leg, and lumbar spine 2. INTRODUCTION: To determine the effectiveness of 6 months of high-impact step aerobics (SA) or moderate-intensity resistance training (RT) on areal bone mineral density (aBMD) and tibial bending strength in sedentary premenopausal women. METHODS: Sixty-nine women (20-35 years old) who were randomly assigned to RT (n = 22), SA (n = 26), or non-treatment control (CON, n = 21) groups completed the study. SA had a minimum of 50 high-impact landings each training session. RT had a periodized lower body resistance training program incorporating eight exercises (65-85% of 1 repetition maximum: 1-RM). Both RT and SA met 3 times weekly. aBMD was assessed using dual X-ray absorptiometry (DXA). Tibial bending strength was assessed using mechanical response tissue analysis (MRTA). Measurements at 6 months were compared to baseline using ANCOVA, adjusted for baseline measures and covariates with α = 0.05. RESULTS: Calcaneus aBMD (0.0176 vs -0.0019 or -0.0009 g/cm2 relative to RT, p < 0.004, and CON, p < 0.006, respectively), lower leg aBMD (0.0105 vs -0.0036 g/cm2, relative to RT, p = 0.02), and lumbar spine 2 (L2) aBMD (0.0082 vs -0.0157 g/cm2 relative to CON, p < 0.02) were significantly greater in the SA group after 6 months. Tibial bending strength and bone resorption biomarkers were unchanged in all three groups after 6 months. CONCLUSION: Sedentary premenopausal women engaging in 6 months of high-impact aerobic exercise improved aBMD in the calcaneus, lower leg, and L2.

Mechanical and physiological examination of barefoot and shod conditions in female runners.

Barefoot running and running using minimalist footwear have become increasingly popular in recent years. Footwear choice may affect running mechanics and the metabolic cost of running. To investigate these factors, 8 well-trained, female distance runners (mean age=20.1±1.4 years) were recruited to participate in the study. Following orientation to testing procedures, subjects completed 3 running economy tests on separate days. Treatment order (barefoot, minimalist footwear and running shoe) was counter-balanced. Each testing session consisted of a 5-min warm-up at 2.24 m · s(-1), followed by the 7-min RE test at 3.13 m · s(-1). Biomechanical data were collected at the 3-min mark for 10 s, and expired gases were collected from minutes 5-7. One-way repeated measures ANOVA revealed a statistically significant difference for running economy (p=0.04), expressed as relative oxygen uptake per km in the barefoot condition (running shoe: 204.51±2.84; minimalist footwear: 198.21±3.04; barefoot: 193.26±3.62 ml · kg(-1)· km(-1)) vs. running shoe. The other physiological and biomechanical variables were not statistically significant (p>0.05). However, moderate to large effect sizes suggested there were biomechanical changes that ensured between conditions. It should be further evaluated whether these mechanical adjustments and the running economy trend would translate into improved distance race performance while running barefoot or with minimalist footwear.

Interactions between adipose, bone, and muscle tissue markers during acute negative energy balance in male rowers.

AIM: The purpose of this investigation was to study the influence of prolonged low-intensity single scull rowing exercise on plasma adipocytokine and osteokine concentrations in trained male rowers. Nine single scull rowers (age: 20.1±1.6 yrs; height: 184.1±4.6 cm; body mass: 81.2±5.3 kg; %body fat: 11.1±3.9) participated in this study. METHODS: Venous blood samples were obtained before and after a ~2 h constant load on-water sculling training session (distance: 20.6±1.5 km; HR: 133±4 bpm; intensity: 80.3±1.7% of the HR turn-point). RESULTS: The training session created an energy deficit of 1 200-1 500 kcal. Plasma adiponectin increased (+12.2%; P<0.05) while leptin decreased (-23.1%; P<0.05) at 30 min postexercise. Plasma osteocalcin (+23.7%; P<0.05) and type I carboxyterminal telopeptide (ICTP) (+28.6%; P<0.05) were increased on completion of the training session. Plasma IL-6 concentration was increased (P<0.05) about four-fold while insulin concentration was decreased (P<0.05) more than three-fold upon completion of exercise. There were no differences in TNF-α, glucose, testosterone and cortisol concentrations over time. Plasma adiponectin (r=0.59) and osteocalcin (r=0.57) concentrations measured immediately after the training session were related (P<0.05) to the distance covered. CONCLUSION: Acute negative energy balance induced by a single endurance rowing training session elicited an inverse metabolic response in adiponectin and osteocalcin concentrations in male rowers. Our results suggest that peripheral markers of negative energy balance, such as adiponectin and osteocalcin, may serve as signals for metabolic reaction to the energy cost of acute exercise in athletes.

Exercise during late-follicular menstrual phase: influence on immune parameters.

AIM: The purpose of this study was to examine whether training status and plasma hormones (estradiol--E2, progesterone--P, luteinizing hormone--LH, and follicle-stimulating hormone--FSH) have an effect on selected immune indexes during or following an acute bout of exercise. METHODS: Seven female triathletes (TRI) and 7 recreationally active (REC) females were randomly assigned to rest (RE) and exercise (EX) trials during the late-follicular menstrual phase (LF). The EX was 1 hour of cycling at 63.1+/-6% VO2peak (TRI) and 61+/-5.1% VO2peak (REC) and RE was 1 hour of sitting. Blood was drawn for both trials at baseline (0H), 1 hour (1H), and at 3 hours (3H). RESULTS: Positive correlations were found between E2 and CD19+ cells for both groups as well as P and CD8+ cells for the REC group. E2 increased during EX and returned to baseline at 3HEX for both groups, however, LH remained elevated at 3HEX for REC. There were significant exercise time effects for CD3+, CD4+, CD8+, and CD3- CD16+ CD56+ cells. The NCMC and 1:1 were elevated at 1HEX for both groups and returned to baseline by 3HEX. During RE, CD3- CD16+ CD56+ cell numbers for both groups and NCMC for REC remained elevated at 3HRE. CONCLUSIONS: E2 and P correlated with CD19+ and CD8+ cells, respectively. Although there were transient exercise-induced changes in immune indexes and E2 and LH, with LH remaining elevated at 3HEX for REC, both training groups elicited similar responses for plasma hormones, lymphocyte subpopulations, and NCMC.

Acute EPOC response in women to circuit training and treadmill exercise of matched oxygen consumption.

The purpose of the study was to evaluate the effects of circuit training (CT) and treadmill exercise performed at matched rates of oxygen consumption and exercise duration on elevated post-exercise oxygen consumption (EPOC) in untrained women, while controlling for the menstrual cycle. Eight, untrained females (31.3 +/- 9.1 years; 2.04 +/- 0.26 l min(-1) estimated VO2max; BMI=24.6+/-3.9 kg/m2) volunteered to participate in the study. Testing was performed during the early follicular phase for each subject to minimize hormonal variability between tests. Subjects performed two exercise sessions approximately 28 days apart. Resting, supine energy expenditure was measured for 30 min preceding exercise and for 1 h after completion of exercise. Respiratory gas exchange data were collected continuously during rest and exercise periods via indirect calorimetry. CT consisted of three sets of eight common resistance exercises. Pre-exercise and exercise oxygen consumption was not different between testing days (P>0.05). Thus, exercise conditions were appropriately matched. Analysis of EPOC data revealed that CT resulted in a significantly higher (p<0.05) oxygen uptake during the first 30 min of recovery (0.27 +/- 0.01 l min(-1) vs 0.23+/-0.01 l min(-1)); though, at 60 min, treatment differences were not present. Mean VO2 remained significantly higher (0.231 +/- 0.01 l min(-1)) than pre-exercise measures (0.193 +/- 0.01 l min(-1)) throughout the 60-min EPOC period (p<0.05). Heart rate, RPE, V(E) and RER were all significantly greater during CT (p<0.05). When exercise VO2 and exercise duration were matched, CT was associated with a greater metabolic disturbance and cost during the early phases of EPOC.

The effects of chondroitin sulfate supplementation on indices of muscle damage induced by eccentric arm exercise.

AIM: Delayed onset of muscle soreness (DOMS) often results from unaccustomed exercise or exercise that involves heavy eccentric loading of skeletal muscle. Chondroitin sulfate (CS) has been reported to possess anti-inflammatory and analgesic properties and has been used widely in the treatment of osteoarthritis. Based on these findings, the investigators sought to determine whether CS supplementation might reduce DOMS symptoms associated with eccentric arm exercise. METHODS: Sixteen non-resistance-trained males participated in a double-blind protocol. Subjects consumed 3,600 mg x day-1 of encapsulated CS or placebo for 14 days preceding the exercise protocol and during 48 hours of follow-up measurements. Subjects performed a maximum of 50 eccentric contractions of the elbow flexors against a resistance that was 120% of the concentric one-repetition maximum. RESULTS: Significant time effects were present for soreness, relaxed elbow extension (joint angle), and creatine kinase; all measures were significantly altered 48 hours after the exercise session. No effects were present for complement system fragment C3a and prostaglandin E2. No significant treatment or interaction effects were detected for any of the variables. CONCLUSIONS: CS supplementation was not found to be effective in the prevention of DOMS, nor did it influence biochemical indices of inflammation and muscle damage following heavy eccentric loading of the arm flexors.

Effects of hormone replacement therapy on selected indices of immune function in postmenopausal women.

The purpose of this study was to examine the effects of long-term hormone replacement therapy (HRT) on selected indices of resting immune function in postmenopausal women. Postmenopausal women aged 54-66 were divided into two groups, those taking HRT (n = 17) and controls (n = 19). Blood samples were obtained and analyzed for mononuclear cell numbers, lymphocyte proliferation (LP) and natural cell-mediated cytotoxicity (NCMC). There were no significant differences between groups for mononuclear cell numbers. LP was significantly higher for HRT, while NCMC was significantly lower for HRT. HRT is currently being prescribed to postmenopausal women for prevention of a variety of medical conditions including osteoporosis, cardiovascular disease, stroke, and Alzheimer's disease yet HRT is often associated with altered immune parameters. In this study, women taking HRT had increased lymphocyte blastogenesis and decreased NCMC compared to controls.

Influence of acute submaximal exercise on T-lymphocyte suppressor cell function in healthy young men.

A defect in T-lymphocyte suppressor cell function has been reported to occur in a number of autoimmune diseases. The influence of exercise on suppressor cell function has not been determined in individuals with autoimmune diseases, nor has it been determined in healthy individuals. The purpose of this investigation was to determine the effect of an acute bout of submaximal exercise on suppressor cell function in healthy males. Each subject (n = 10) completed an exercise trial (E; 1 h of cycle ergometry at 70.6% of maximal oxygen uptake, followed by 2 h of recovery) and a resting trial (R; 3 h of seated rest), separated by at least 1 week. Treatment (E or R) order was counterbalanced. Venous blood samples were obtained pre-exercise (PRE), immediately after exercise (POST), and 2 h post-exercise (2HPOST), and at the same time points in the R trial. Lymphocyte phenotype percentages were determined by flow cytometry, while concanavalin-A-induced suppressor cell function was determined on peripheral blood mononuclear cells. No change was observed in the percentage of T-cytotoxic/suppressor cells. Suppressor cell function was significantly different between treatments, with the POST E value [mean (SD) 56.8 (1.6)%] being higher than the POST R value [41.7 (1.9)%]. No significant difference was observed 2HPOST. In conclusion, acute submaximal exercise resulted in a transient increase in suppressor cell function in healthy males.

Pre-exercise carbohydrate and fluid ingestion: influence of glycemic response on 10-km treadmill running performance in the heat.

BACKGROUND: The purpose of this study was to determine the influence of ingesting solutions containing mixtures of carbohydrate (CHO) types on pre-exercise glycemic response, exercise-induced hypoglycemia, metabolic responses, and 10-km treadmill running performance in a warm environment. METHODS: Ten trained runners completed 6, self-paced 10-km treadmill runs one hour after ingesting 900 ml of one of the following test solutions: a water placebo (WP), an 8 g 100 ml-1 high fructose corn syrup solution (HFG; 72 g CHO), a 6 g 100 ml-1 glucose solution (GLU; 54 g CHO), a 6 g.100 ml-1 sucrose/glucose mixture (SUG; 54 g CHO), or banana with water to equal 900 ml (BAN; approx. 54 g CHO). The sixth condition was 675 ml of an 8 g.100 ml-1 HFCS solution (LFG; 54 g CHO). Blood samples were taken prior to ingestion and every 15 min during rest and at 15 and 30 min, and at the end of the 10-km run. Blood was analyzed for glucose (BG) insulin (IN), glycerol, lactate, and percent change in plasma volume. Urine volume during the 1 hour of rest and change in body mass during exercise were also determined. RESULTS: A significant (p < 0.05) correlation (r = -0.684) was seen between the pre-exercise glycemic response (PEGR = area under the resting BG curve) and the change in BG from pre-EX to 15 min of exercise. BG at 15 min of exercise was significantly higher in the WP (5.22 mM) versus the other conditions (HFG = 3.32, LFG = 3.91, GLU = 3.38, BAN = 3.74 & SUG = 3.63 mM). Pre-exercise IN was lower in the WP (6.54 U ml-1) condition versus the other conditions (HFG = 22.1, LFG = 16.2, GLU = 23.3, BAN = 18.8 & SUG = 12.8 U.ml-1). Ten km performance times were not different (WP = 41.87, HFG = 41.66, LFG = 41.79, GLU = 41.65, BAN = 41.53, and SUG = 41.75 min). A significantly greater body mass loss occurred due to urine production during the 60 min of rest in the WP compared to the other conditions. The degree of exercise-induced decline in blood glucose was related to the PEGR; however, the decline in BG did not affect 10-km running performance. In addition, there were no differences in the metabolic responses during exercise between the different CHO types, nor did the type of CHO influence running performance. Finally, the presence of CHO and/or electrolytes in the hydration solutions produced a better fluid retention during the 60-min pre-exercise rest period compared to water. CONCLUSIONS: The results confirmed that if a competitive athlete consumed a breakfast prior to ingesting a CHO-electrolyte beverage, a practice that is common, the glycemic responses may be different.

Effects of endurance training on selected parameters of immune function in elderly women.

BACKGROUND: Immune function decreases with age, rendering the elderly more susceptible to infection and tumor development. In addition, intense exercise has been shown to decrease immune function in some populations. Few studies have examined the effects of exercise on immune function in the elderly and, to our knowledge, no studies have examined the effects of exercise on a population of active, but nonexercising elderly. OBJECTIVE: The purpose of this study was to examine the effects of a 10-week endurance training program on selected parameters of immune function in active elderly women. METHODS: A total of 29 healthy, active women, aged 70-87, were randomly assigned to either an exercise (76 +/- 5 years, n = 15) or control (77 +/- 6 years, n = 14) group. The exercise group walked 3 days/week at 70% heart rate reserve (HRR). The duration on day 1 was 20 min and it was increased by 5 min each day until subjects were walking for 50 min (week 3). It remained at 50 min for the duration of the study, while controls maintained normal activity. Blood samples were obtained from both groups at rest, and from the exercise group after 20 min of walking at 70% HRR and after 2 h of recovery. Blood samples were collected prior to endurance training and again after 10 weeks of endurance training. RESULTS: There was a significant decrease in 1-mile walk times as well as heart rate at completion of the walk in the exercise group. Natural cell-mediated cytotoxicity (NCMC) was significantly higher post-exercise, compared to pre-exercise both before and after training. After training it remained significantly elevated 2 h post-exercise. The resting NCMC was significantly decreased in controls at week 10 but not in the exercise group. CONCLUSION: Ten weeks of endurance training resulted in a significant decrease in both the 1-mile walk time and the post-walk heart rate in the exercisers but not the controls, without resulting in either an acute or chronic suppression of immune function. Further, endurance training may lead to an attenuation of the decrease in cellular immune measures which occurs during the winter, since the control group experienced a decrease in NCMC and the exercisers did not.

Iron status and resting immune function in female collegiate swimmers.

Iron deficiency may lead to anemia and may result in compromised endurance exercise performance. Iron deficiency has also been reported to adversely affect the immune system and has been associated with attenuation of natural killer cell (NK) activity. This study was conducted to examine the relationship between iron status and NK activity in highly conditioned female athletes. Ten collegiate female swimmers (SWM) and 9 inactive females (SED) participated in this investigation. Resting blood samples were obtained and analyzed for serum iron and ferritin. NK activity (% lysis) was determined using a whole blood method (51Cr release assay). No significant relationship was found between iron and NK activity (r = 0.55, p =.09), nor between serum ferritin and NK activity (r = 0.33, p =.35) for SWM. ANOVA revealed significantly greater NK activity for SWM (51.63 +/- 15.79%) versus SED (30.34 +/- 13.67%). Serum ferritin levels were not significantly different between SWM (20.38 +/- 8.62 hg á ml-1) and SED (16.79 +/- 10.53 hg á ml-1), nor were iron values different between groups (16.54 +/- 2. 17 mmol á L-1 SWM; 11.92 +/- 2.61 mmol á L-1 SED). A significant relationship between iron status and resting immune function could not be established. Exercise training may affect NK activity; however, the influence of iron status on immune function requires further evaluation.

Indomethacin does not influence natural cell-mediated cytotoxic response to endurance exercise.

Natural cell-mediated cytotoxicity (NCMC) has been shown to be attenuated during recovery from high-intensity or prolonged exercise. Two theories have been proposed to explain the transient suppression of NCMC: prostaglandin-induced inhibition of natural killer (NK) cell activity or a numerical redistribution of NK cells. This study was designed to examine the effects of oral indomethacin (a prostaglandin inhibitor) on NCMC before and after 1 h of high-intensity running (85% maximal oxygen uptake). A secondary purpose was to compare whole blood and isolated peripheral blood mononuclear cell assay procedures for assessing NCMC. Ten male distance runners completed two trials that were preceded by either 48 h of indomethacin (Indo; 150 mg/day) or no treatment (control). NK (CD3(-)/CD16(+)/CD56(+)) cell concentrations were significantly elevated postexercise but were not affected by Indo. NCMC was significantly suppressed at 1.5 h of recovery relative to preexercise only with the whole blood assay procedure. Indo was not found to influence NCMC, leukocyte, or lymphocyte subset concentrations. Mean cytotoxic response was significantly greater with the whole blood method.

Effects of resistance training on selected indexes of immune function in elderly women.

Women aged 67-84 yr were randomly assigned to either resistance exercise (RE, n = 15) or control group (C, n = 14). RE group completed 10 wk of resistance training, whereas C group maintained normal activity. Blood samples were obtained from the RE group (at the same time points as for resting C) at rest, immediately after resistance exercise, and 2 h after exercise before (week 0) and after (week 10) training. Mononuclear cell (CD3+, CD3+CD4+, CD3+CD8+, CD19+, and CD3-CD16+CD56+) number, lymphocyte proliferative (LP) response to mitogen, natural cell-mediated cytotoxicity (NCMC), and serum cortisol levels were determined. Strength increased significantly in RE subjects (%change 8-repetition maximum = 148%). No significant group, exercise time, or training effects were found for CD3+, CD3+CD4+, or CD3+CD8+ cells, but there was a significant exercise time effect for CD3-CD16+CD56+ cells. LP response was not different between groups, across exercise time, or after training. NCMC was increased immediately after exercise for RE subjects at week 0 and for RE and C groups at week 10. The week 0 and week 10 NCMC values were above baseline for both RE and C groups 2 h after exercise. In conclusion, acute resistance exercise did not result in postexercise suppression of NCMC or LP, and 10 wk of resistance training did not influence resting immune measures in women aged 67-84 yr.

The effects of swimming and running on energy intake during 2 hours of recovery.

OBJECTIVE: To determine energy intake in the 2 hrs after swimming (S) and running (R) at the same relative exercise intensity and duration (71.8 +/- 2.5% VO2max; 45 min) to evaluate whether a difference in recovery energy intake could explain the greater body fat observed in swimmers relative to runners. EXPERIMENTAL DESIGN: this was a randomized crossover design. SETTING: running exercise was conducted on a motorized treadmill (Quinton) while swimming was conducted in a 45.7 m pool. PARTICIPANTS: eight well-trained competitive male triathletes participated in this investigation. INTERVENTIONS: subjects were blinded to the purpose of the study and swam and ran on separate occasions for 45 min at 71.8 +/- 2.5% of VO2max. Subjects were then placed in a room with a variety of foods and beverages for 2 hrs after R and S. MEASURES: energy intake (kJ/2 hrs and kcal/2 hrs) was determined by weighing and measuring the food remaining in the room after 2 hrs of postexercise recovery. Expired gases, heart rates, and Ratings of Perceived Exertion were obtained at 15 min intervals throughout exercise. Blood samples for serum glucose and lactate were obtained preexercise and immediately, 15 min, and 135 min postexercise. Perceived hunger and thirst ratings were obtained after the subjects were seated in the room containing the food. RESULTS: Serum glucose was significantly (p < or = 0.05) higher after R compared to S immediately after exercise (5.4 +/- 0.3 mmol/L for R and 4.2 +/- 0.1 mmol/L for S) but no significant differences were observed for hunger using a five point Likert scale (3.3 +/- 0.3 for R and 3.4 +/- 0.3 for S), energy intake (4584 +/- 611 kJ/2 hrs; 1095 +/- 146 kcal/2 hrs for R and 4383 +/- 484 kJ/2 hrs; 1047 +/- 116 kcal for S) or blood lactate. CONCLUSION: The type of exercise, swimming or running, did not significantly influence energy intake during 2 hours of postexercise recovery.

Influence of carbohydrate status on immune responses before and after endurance exercise.

To determine the effect of carbohydrate (CHO) status on immune responses after long-duration exercise, on two occasions, 10 men completed a glycogen-depleting bout of cycle ergometry followed by 48 h of either a high-CHO diet (HiCHO; 8.0 g CHO/kg) or a low-CHO diet (LoCHO; 0.5 g CHO/kg). After the 48 h, subjects completed a 60-min ride at 75% maximal O2 uptake (EX). Blood samples were taken predepletion, pre-EX, post-EX, and 2 and 24 h post-EX and were assayed for leukocyte number and function, glucose, glutamine, and cortisol. The glucose responses were significantly higher in the HiCHO (4.62 +/- 0.26 mM) vs. the LoCHO (3.19 +/- 0.15 mM) condition post-EX, and glutamine was significantly higher in the HiCHO (0.472 +/- 0.036 mM) vs. the LoCHO (0.410 +/- 0.025 mM) condition throughout. Cortisol levels were significantly greater in the LoCHO (587 +/- 50 nM) vs. the HiCHO (515 +/- 62 nM) condition throughout the trial. Lymphocyte proliferation (phytohemagglutinin) was significantly depressed after exercise. However, there was no difference between conditions, and the depression was not correlated with elevations in cortisol. Circulating numbers of leukocytes, neutrophils, lymphocytes, and lymphocyte subsets were significantly greater in the LoCHO vs. the HiCHO condition at the post-EX and 2 h post-EX time points. These data indicate that the exercise and diet manipulation altered the number of circulating leukocytes but did not affect the decrease in lymphocyte proliferation that occurred after exercise.

Effect of 4 wk of deep water run training on running performance.

The purpose of this study was to determine whether trained competitive runners could maintain on-land running performance using 4 wk of deep water run training instead of on-land training. Eleven well-trained competitive runners (10 males, 1 female; ages, 32.5 +/- 5.4 yr; height, 179.8 +/- 9.3 cm; weight, 70.4 +/- 6.7 kg (mean +/- SD)) trained exclusively using deep water run training for 4 wk. Subjects trained 5-6 d.wk-1 for a total of 20-24 sessions (mean +/- SD, 22 +/- 1.5 sessions). Instruction and practice sessions were conducted prior to the training period. Before and after the deep water run training, subjects completed a 5-km race on the treadmill using a computer based system, a submaximal run at the same absolute workload to assess running economy, and a combined lactate threshold and maximal oxygen consumption test. No significant differences were found for (mean +/- SEM): 5-km run time (pre, 1142.7 +/- 39.5 s; post, 1149.8 +/- 36.9 s; P = 0.28), submaximal oxygen consumption (pre 44.8 +/- 1.2 mL.kg-1.min-1; post, 45.3 +/- 1.5 mL.kg-1.min-1; P = 0.47), lactate threshold running velocity (pre, 249.1 +/- 0.9 m.min-1; post, 253.6 +/- 6.3 m.min-1; P = 0.44), or maximal oxygen consumption (pre, 63.4 +/- 1.3 mL.kg-1.min-1; post, 62.2 +/- 1.3 mL.kg-1.min-1; P = 0.11). Also no differences were found among Global Mood State pre-training, each week during training, and post-training. Competitive distance runners maintained running performance using 4 wk of deep water run training as a replacement for on-land training.

Maximal accumulated oxygen deficit of resistance-trained men.

The primary purpose of the study was to compare maximal accumulated oxygen deficit (MAOD) in resistance-trained (RT), endurance-trained (ET), and untrained men (UT). A secondary purpose was to determine the influence of leg muscle mass (MM) on MAOD by examining the relationship between MM and MAOD and by comparing MAOD expressed relative to MM between the groups. MAOD was determined during 2-4 min of constant-load fatiguing cycling. MM, estimated via anthropometric measurements, was higher (p < .05) for RT (mean +/- SE; 25.5 +/- 3.4 kg) compared to ET (20.3 +/- 3.5) and UT (21.6 +/- 3.4). MAOD in liters O2eq was larger in RT (4.75 +/- 0.3) compared to UT (3.07 +/- 0.3) and ET (3.75 +/- 0.3). A significant positive correlation was observed between MAOD (LO2eq) and MM (kg) for RT only (RT, r = .85; ET, r = .55; UT, r = .20). Based on the correlational and mean MM data, the higher MAOD (LO2eq) in RT relative to ET and UT is predominantly the result of their larger leg muscle mass.

A linkage study of HLA and inherited adenocarcinoma of the colon.

A kindred with the familial cancer syndrome is reported in which every confirmed affected member of the pedigree had at least one primary carcinoma of the colon. The average age at which cancer appeared was 38 years, and multiple primary neoplasm occurred in 23% of the cancer patients. Transmission of the cancer trait is consistent with an autosomal dominant mode of inheritance. Colonoscopy eliminated the presence of any unsuspected cancers in family members at risk. HLA typing was done, and by direct typing or inference, data were available on 66 living and deceased individuals. There were four informative matings in the kindred, the offspring of which showed only three crossovers of a possible 17. The lod score totaled 1.06 at a recombination fraction of 0.20. The need for cooperative efforts of many investigators in HLA linkage studies is emphasized, along with the potential value of such an approach.