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Biomedical subjects

F I Katch

Publications and source records attributed to F I Katch.

At least 19 recordsLinked to original sources
PubMed1996

Multivariate allometric scaling of men's world indoor rowing championship performance.

The World Indoor Rowing Championship (WIRC) is based on the time (T) to row a simulated 2500 m on a rowing ergometer. In the WIRC there are separate age categories but only two weight classes: light and heavyweight, thus penalizing those just heavier and those significantly lighter than the cut-off weight. Multivariate allometric scaling (MAS) provides an expression of performance free of the confounding effect of more than one scaling variable. We used MAS to scale T by height (H) and age (A) to create a new index of rowing performance, T*H(-a)*A(-b). Subjects were 148 male competitors from the 1995 WIRC. MAS indicated that T*H*A(-0.06) expresses T free of the confounding effect of H and A. We also scaled T only by H on those subjects, A < 40, (N = 109). Results showed that T*H is an optimal and particularly feasible scaling of T. Use of either convention dramatically changed race results. In conclusion, we recommend use of either the T.H (17 < or = A < or = 39) or T*H*A(-0.06) conventions to adjust WIRC performance in adult males.

Age Factors↗
PubMed1996

Ratio scaling of VO2max penalizes women with larger percent body fat, not lean body mass.

VO2max expressed in ml.BM-1.min-1 (BM = body mass) has been shown to unduly penalize heavier subjects and instead should be expressed as ml.BM-0.7.min-1. Such findings support the "theory of similarity" (TofS) that proposes the BM exponent should be 2/3 (0.67). The TofS, however, applies better to lean body mass (LBM) that is uninfluenced by fat mass. For young adults, the actual scaling exponent of LBM has yet to be satisfactorily determined. We used allometric scaling (AS) to scale VO2max by BM and LBM in 94 women (age = 27.4 +/- 6.7 yr, BM = 60.3 +/- 8.4 kg). Treadmill VO2max was assessed by indirect calorimetry and LBM was determined from hydrostatic weighing. AS yielded the following exponents (+/- 95% C.I.): BM: 0.61 +/- 0.27, and LBM: 1.04 +/- 0.26. We conclude that VO2max in ml.BM-1.min-1 indeed penalizes heavier women, but this penalty applies only to those who are heavier because of larger percent body fat, not LBM. If one takes the position that excess fatness is undesirable, then from a health and performance perspective, expressing VO2max in ml.BM-1.min-1 may provide an unbiased and useful expression of VO2max in young women.

Adipose Tissue↗
PubMed1995

U.S. government raises serious questions about reliability of U.S. Department of Agriculture's Food composition database.

A recent government report from the General Accounting Office concludes that some Handbook 8 nutritional data have so little documentation on how the data were produced that it is possible some nutrient values are not reliable, and that HNIS does not appropriately direct the generation of food composition data under its contracted laboratory studies. The report recommends that the Secretary of Agriculture direct the HNIS administrator to develop (a) specific quality assurance criteria for HNIS staff to use in evaluating food composition data obtained from others before the data are included in Handbook 8, and (b) procedures to better direct the generation of food composition data under HNIS' contracts.

Food↗
PubMed1992

Relationship among selected performance measures on the Omnitron Total Power Unit.

The present study assessed the interrelationships among selected performance parameters on the Omnitron Total Power Unit. Forty-eight males (18 to 31 yrs) repeated on 2 days the chest press, shoulder press, lat row, and lat pull-down exercises at low, medium, and high levels of resistance. Test-retest reliability for peak force, average linear velocity, and average power output ranged form r = 0.71 to r = 0.97 (p less than 0.05) (29 of 36 correlations greater than or equal to 0.9), and demonstrate that the different testing protocols provide reliable individual differences for assessing muscular performance. The average linear velocity and average power output data provide little new information about muscular performance besides that attained from peak force analysis. The percentage common variance among the levels of resistance and output modes ranged from 90 to 98%. Thus, assessing peak force at a single level of resistance on the Omnitron is sufficient to obtain an overall assessment of muscular performance.

Adolescent↗
PubMed1991

A new approach to rowing ergometry: establishing exercise intensity relative to maximum force output.

The present experiment evaluated a new approach to establish exercise intensity during hydraulic rowing ergometry. In contrast to the traditional approach where exercise intensity is augmented by systematically increasing workload, the new procedure increments the intensity of exercise while maintaining a constant percentage of maximum force output. Ten college females exercised on a hydraulic rower that allowed for control of rowing speed and resistance. The new method to establish work intensity was to row at a cadence of 30 c.min-1 at a force output equal to 50% of maximum rowing force at each setting determined dynamically prior to testing. Two protocols were used for the maximum tests on the hydraulic rower. Row 1 was a 17-min, six-stage, incremental continuous row test performed at increasingly difficult settings from easy (setting 1; 603 N) to difficult (setting 6; 893 N). Row 2 was identical to row 1 until 15 min when resistance was reduced to setting 2 (658 N) for "allout" effort during the last 2 min. During this time, cadence declined from 30 c.min-1 to 19.4 c.min-1 at dial setting 6 and increased to 35.4 c.min-1 at dial setting 2. Both rowing protocols were compared to maximal physiological responses during treadmill running (TM). Compared to TM, both rowing protocols elicited significantly lower maximum oxygen uptake (VO2max; P less than 0.05; row 1 = delta 29.0% and row 2 = delta 12.9%) and maximum heart rate (HRmax; P less than 0.05; row 1 = delta 12.9% and row 2 = delta 6.7%). Maximum ventilation (VEmax) during row 1 was also lower by 30.4% than TM (P less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Energy Metabolism↗
PubMed1991

Effects of simultaneous training for strength and endurance on upper and lower body strength and running performance.

This study examined simultaneous training for strength and endurance during a 13-week, 3-day a week program of hydraulic resistive circuit training and running. Eighteen college males (U.S. Army ROTC) were placed into low resistance (LR; n = 10) or high resistance (HR; n = 8) groups, and 10 college males were controls and did not train. There were 20 exercise stations (7 upper and lower body, and 6 supplementary). LR and HR performed 2 circuits with a work/rest ratio of 20 to 40 s during the 40 min workout. LR trained at two low resistances (approximately 100 cm.s-1), while HR trained at a higher resistance (approximately 50 cm.s-1). Following the workout, subjects ran 2 miles. Pre and post tests included strength, physical fitness, and anthropometry. Strength was assessed with (1) hydraulic resistance dynamometry for 4 exercises at 2 speeds using a computerized dynamometer (Hydra-Fitness, Belton, TX); (2) isokinetic and isotonic upright squat and supine bench press using the Ariel Exerciser (Trabuco Canyon, CA); (3) concentric and eccentric arm flexion/extension at 60 and 120 degrees.s-1 on the Biodex dynamometer (Shirley, NY), and (4) 1-RM free weight concentric and eccentric arm flexion and extension. The fitness tests included 2-mile run, sit-ups, and push-ups. Anthropometry included 3 fatfolds, 6 girths, and arm and leg volume. There were no significant changes in body composition or interactions between the fitness test measures and the 2 training groups (p greater than 0.05). Improvements averaged 15% (run time), 30% (push-ups), and 19% (sit-ups; p less than 0.05). Significant improvements also occurred in 3 of 8 measures for hydraulic testing (overall change 8.8%), in 3 of 4 1-RM tests (9.4%), and in 2 of 8 Biodex tests (6%), but no significant changes for isokinetic and isotonic squat and bench press (1.9%). The change in overall strength averaged 6.5% compared to 16% in a prior study that used hydraulic resistive training without concomitant running. We conclude that gains in strength were somewhat compromised by the simultaneous run training, and that improvements in strength and run performance were independent of LR and HR training intensity.

Adult↗
PubMed1990

Eccentric and concentric torque-velocity relationships during arm flexion and extension. Influence of strength level.

Forty men were tested with a computerized dynamometer for concentric and eccentric torques during arm flexion and extension at 0.52, 1.57, and 2.09 rad.s-1. Based on the summed concentric and eccentric torque scores, subjects were placed into a high strength (HS) or low strength (LS) group. The eccentric and concentric segments of the torque-velocity curves (TVCs) were generated using peak torque and constant-angle torque (CAT) at 1.57 and 2.36 rad. Angle of peak torque was also recorded. Compared to LS, HS had significantly greater estimated lean body mass (+10.2 kg) and approximately 25% greater average torque output. Reliability of the peak torque scores on 2 days in 20 subjects was r greater than or equal to 0.85. The difference between observed torques and the mathematically computed criterion torque scores averaged 1% for three validation loads that ranged from 11.4 to 90.4 kg. Statistical analysis revealed that torque output in LS plateaued at low concentric velocities and was also flattened with increasing eccentric velocities. Conversely, torque output for HS increased with decreasing concentric velocities and increased with increasing eccentric velocities. The method of plotting the TVCs for peak or CAT did not influence the pattern of TVC. Eccentric flexion peak torque occurred at a significantly shorter muscle length (1.88 rad) than concentric torque (2.12 rad). This difference was also present for extension; it was 1.88 rad for eccentric and 2.03 rad for concentric torque.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1990

Proprioceptive facilitation of muscle tension during unilateral and bilateral knee extension.

The effects of double neuromuscular facilitation (DNF) in unilateral movements and of quadruple neuromuscular facilitation (QNF) in bilateral movements were studied in 42 physically active college-age male subjects. Results showed a 10.4% significant increase of maximal knee extension torque output when unilateral extension was preceded by a knee flexion on an isokinetic exerciser and a 16.7% increase of maximal torque in the bilateral condition of simultaneous alternating flexion-extension when compared to the simultaneous extension movement. Consequently, the increased peak torque observed in the unilateral and bilateral experimental conditions in which knee extension was preceded by a knee flexion appears to be the result of a combination of neuromuscular influences and stored elastic energy.

Adult↗
PubMed1990

Relationships of body size, segmental dimensions, and ponderal equivalents to muscular strength in high-strength and low-strength subjects.

There are conflicting results in prior studies concerning the relationships among body size, muscle size, and muscular strength. The purpose of the present study was to evaluate how body size, body shape, and segmental dimensions related to individual differences in muscular strength. Subjects were tested on four dynamic measures of strength and then classified into one of two groups as high strength (HS; N = 21) and low strength (LS; N = 21). Individual differences in strength were then related to body composition and segmental anthropometry. Strength was assessed during high-resistance, low-velocity standing squat and supine bench press with an isokinetic dynamometer, and during seated bench press and knee extension with a hydraulic resistance dynamometer. Anthropometry and body composition included 11 girths, six fatfolds, predicted fat-free mass (FFM), thigh and upper arm volume, muscle + bone cross-sectional area (CSA), and the Behnke Ponderal Somatogram (PSom) body profiling system. There was a 21.3% difference in strength between HS and LS (p less than 0.05), but no significant differences in age, stature, and fatfolds. MANOVA revealed that seven of 11 girth components of PSom were larger for HS (p less than 0.05). The correlations between strength vs body mass, FFM, thigh and upper arm volume, and CSA and fatfolds in HS and LS ranged from r = -0.52 to 0.56 (r = -0.70 to 0.70 when corrected for restriction of range). We conclude that individual differences in muscular strength are poorly related to various measures of body size and segmental body dimensions.

Adult↗
PubMed1990

Validity of surface anthropometry to estimate upper-arm muscularity, including changes with body mass loss.

The differences among fatfold thicknesses, girths, and muscle plus bone cross-sectional area (M+B CSA) were examined at three sites along the upper arm (distal, mid, and proximal) by using surface anthropometry (study 1, n = 40) and x ray (study 2, n = 53). Changes in anthropometry and x ray were also evaluated in nine obese patients who reduced body mass by less than or equal to 20.5 kg over 32 wk. Weight reduction resulted in nonproportional changes at the three sites, including significant differences in M+B CSA. Thus, it would not be valid to consider the arm as a geometric cylinder. Although a one-time assessment of upper arm M+B CSA with surface anthropometry may be valid at any of the three sites, changes in M+B CSA measured at any site may result in an under- or overestimation of actual changes in M+B CSA.

Adipose Tissue↗
PubMed1990

Role of concentric force in limiting improvement in muscular strength.

We hypothesized that resistance training with combined eccentric and concentric actions, and concentric action only, should yield similar changes in muscular strength. Subjects in a free weight group trained three times a week for 12 wk with eccentric and concentric actions (FW, n = 16), a second group trained with concentric-only contractions using hydraulic resistance (HY; n = 12), and a control group did not train (n = 11). Training for FW and HY included five sets of supine bench press and upright squat at an intensity of 1-6 repetition maximum (RM) plus five supplementary exercises at 5-10 RM for a total of 20 sets per session for approximately 50 min. Testing at pre-, mid-, and posttraining included 1) 1 RM bench press and squat with and 2) without prestretch using free weights; 3)isokinetic peak force and power for bench press and squat at 5 degrees/s, and isotonic peak velocity and power for bench press with 20-kg load and squat with 70-kg load; 4) hydraulic peak bench press force and power, and peak knee extension torque and power at fast and slow speeds; and 5) surface anthropometry (fatfolds and girths to estimate upper arm and thigh volume and muscle area). Changes in overall fatness, muscularity, and muscle + bone cross-sectional area of the limbs did not differ between groups (P greater than 0.05). Improvements in free weight bench press and squat were similar (P greater than 0.05) in FW (approximately 24%) and HY (approximately 22%, P less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1989

Interrelationships among various measures of upper body strength assessed by different contraction modes. Evidence for a general strength component.

Two studies were conducted in 83 college men to determine the degree of generality of individual differences in upper body muscular strength assessed by different testing modes. In study 1 (N = 43), correlations were computed between four measures of upper body strength using the bench press movement, maximal isokinetic (0.09 rad.s-1), maximal fast (0.126 m.s-1) and slow (0.037 m.s-1) hydraulic, and one repetition maximum (1-RM) free weight bench press (BP). Compared to free weight BP, maximal strength during isokinetic and slow hydraulic BP was approximately 29% and approximately 8% larger, and fast hydraulic BP strength was approximately 63% lower (p less than 0.05). Simple linear regression of isokinetic BP on 1-RM BP yielded r = 0.79, error of prediction (SE) = 12%, and generality = 81%. The corresponding averaged values for the regression of slow and fast hydraulic BP on free weight 1-RM BP were r = 0.77, SE = 13.5%, and generality = 84%. In Study 2 (N = 40), testing included maximal isokinetic concentric and eccentric arm flexion and extension at 0.524, 1.570, and 2.094 rad.s-1. The ratio of concentric to eccentric torque at the 3 speeds averaged 0.68 (flexion) and 0.70 (extension), and eccentric torques were 32% and 30% greater than concentric torques (p less than 0.05). The linear regression between concentric vs. eccentric flexion and extension torques at the three velocities yielded an average r = 0.80, SE = 13.7%, and generality = 73%.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1989

Reliability and validity of the Omnitron hydraulic resistance exercise and testing device.

This study assessed the measurement reliability and validity of the Hydra-Fitness Omnitron, a microprocessor-controlled isokinetic ergometer that provides concentric resistance for dynamic extension and flexion movements as well as resistance for isometric contractions. Maximal peak torque output measured by the Omnitron and strain gauge devices connected to the apparatus were compared in 26 physically active males who were tested over 3 days for isometric knee extension and isokinetic knee flexion/extension at two resistance levels. Maximal torque outputs remained stable on days 2 and 3 (p less than 0.05), and intraclass reliability yielded r = 0.94 to 0.98. There was no difference between the slopes of the regression lines for the different experimental conditions (p less than 0.05). There was significant improvement between day 1 and days 2 and 3 that corresponded to a combination of a training and learning effect. Thus, one practice session was necessary to obtain reliable individual differences. The validity correlations between peak torque output measured from the Omnitron and strain gauges were greater than r = 0.94. There was a small discrepancy (0.44 to 0.88 Nm) between the two measuring devices that can be explained by the difference in shank pad positioning that accommodates for different segment lengths. We conclude that reliability and validity were excellent over a wide range of torque outputs measured during maximal isometric and maximal dynamic double concentric flexion and extension movements.

Adult↗