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Purpose To compare the effects of strength training versus ski-ergometer training on double-poling gross efficiency (GE), maximal speed (Vmax), peak oxygen uptake (V˙O2peak" role="presentation" style="box-sizing: border-box; display: inline-table; line-height: normal; letter-spacing: normal; word-spacing: normal; word-wrap: normal; white-space: nowrap; float: none; direction: ltr; max-width: none; max-height: none; min-width: 0px; min-height: 0px; border: 0px; padding: 0px; margin: 0px; position: relative;">V˙O2peakV˙O2peak) for elite male and female junior cross-country skiers. Methods Thirty-three elite junior cross-country skiers completed a 6-week training-intervention period with two additional 40-min training sessions per week. The participants were matched in pairs and within each pair randomly assigned to either a strength-training group (STR) or a ski-ergometer-training group (ERG). Before and after the intervention, the participants completed three treadmill roller-skiing tests to determine GE, Vmax, and V˙O2peak" role="presentation" style="box-sizing: border-box; display: inline-table; line-height: normal; letter-spacing: normal; word-spacing: normal; word-wrap: normal; white-space: nowrap; float: none; direction: ltr; max-width: none; max-height: none; min-width: 0px; min-height: 0px; border: 0px; padding: 0px; margin: 0px; position: relative;">V˙O2peakV˙O2peak. Mixed between-within subjects analysis of variance (ANOVA) was conducted to evaluate differences between and within groups. Paired samples t tests were used as post hoc tests to investigate within-group differences. Results Both groups improved their Vmax and V˙O2peak" role="presentation" style="box-sizing: border-box; display: inline-table; line-height: normal; letter-spacing: normal; word-spacing: normal; word-wrap: normal; white-space: nowrap; float: none; direction: ltr; max-width: none; max-height: none; min-width: 0px; min-height: 0px; border: 0px; padding: 0px; margin: 0px; position: relative;">V˙O2peakV˙O2peak expressed absolutely (all P V˙O2peakV˙O2peak expressed absolutely (all P

This study investigated changes in technique and efficiency after high-intensity exercise to exhaustion in elite cross-country skiers. Twelve elite male skiers completed 4 min submaximal exercise before and after a high-intensity incremental test to exhaustion with the G3 skating technique on a 5% inclined roller-ski treadmill. Kinematics and kinetics were monitored by instrumented roller skis, work rate was calculated as power against roller friction and gravity, aerobic metabolic cost was determined from gas exchange, and blood lactate values indicated the anaerobic contribution. Gross efficiency was the work rate divided by aerobic metabolic rate. A recovery period of 10 min between the incremental test and the posttest was included to allow the metabolic values to return to baseline. Changes in neuromuscular fatigue in upper and lower limbs before and after the incremental test were indicated by peak power in concentric bench press and squat-jump height. From pretest to posttest, cycle length decreased and cycle rate increased by approximately 5% (P < 0.001), whereas the amount of ski forces did not change significantly. Oxygen uptake increased by 4%, and gross efficiency decreased from 15.5% ± 0.7% to 15.2% ± 0.5% from pretest to posttest (both P < .02). Correspondingly, blood lactate concentration increased from 2.4 ± 1.0 to 6.2 ± 2.5 mmol/L (P < .001). Bench-press and squat-jump performance remained unaltered. Elite cross-country skiers demonstrated a less efficient technique and shorter cycle length during submaximal roller-ski skating after high-intensity exercise. However, there were no changes in ski forces or peak power in the upper and lower limbs that could explain these differences.

Entropy method and Data Envelopment Analysis (DEA) method are adopted to carry out an effective analysis on the circular economy development of Liaoning Province between 1992 to 2011, and the results show that: the decentralization strength of input-output efficiency of Liaoning Province in this period was great, the gross efficiency of circular economy development was shocking while improving and the development trend varied in different stages; the scale efficiency was higher, and the influence of scale efficiency was higher than technical efficiency, so it can still obtain higher gross efficiency through expanding production scale. Legislation, technological innovation, green consumption and policy support are key measures for promoting the circular economy development.

The purpose of this study was to investigate and compare skiing economy and gross efficiency in cross-country skiers of different performance levels, ages and genders; male recreational skiers and elite senior and junior cross-country skiers of both genders. The skiers performed tests involving roller skiing on a treadmill using the gear 3 and diagonal stride techniques. The elite cross-country skiers were found to have better skiing economy and higher gross efficiency (5-18%) compared with the recreational skiers (p0.05) and the senior elite had better economy and higher efficiency (4-5%) than their junior counterparts (p0.05), whereas no differences could be found between the genders. Also, large ranges in economy and gross efficiency were found in all groups. It was concluded that, in addition to V[Combining Dot Above]O2peak, skiing economy and gross efficiency have a great influence on the differences in performance times between recreational and junior and senior elite cross-country skiers, as well as between individual skiers within the different categories. Thus, we recommend cross-country skiers at all performance levels to test not only V[Combining Dot Above]O2peak, but also skiing economy and efficiency.

To determine the effects of push frequency changes on force application, fraction of effective force (FEF) and gross efficiency (GE) during hand-rim propulsion. 8 male able-bodied participants performed five 4-min sub-maximal exercise bouts at 1.8 m.s(-1); the freely chosen frequency (FCF), followed by 4 counter-balanced trials at 60, 80, 120 and 140 % FCF. Kinetic data was obtained using a SMART(Wheel), measuring forces and moments. The GE was determined as the ratio of external work done and the total energy expended. Increased push frequency led to reductions in peak resultant force (P

Purpose: This study was conducted to investigate whether the pedaling frequency at a constant mechanical power contributes to the cycling efficiency (η gross and η net) , and the rate of fat and carbohydrate utilization during submaximal cycling exercise. Methods: Healthy, recreationally active men (n=ll) and women (n=5) cycled 5 min at workloads of about 54 watts at pedaling frequency of 45, 60 and 90 revolutions/min, respectively, and rested 3 min at approximately equal interval until the following step. Results: Mean Gross Efficiency (η gross) significantly decreased from 17.98±1.97% and 16.77±0.94%, at 45 rpm and 60 rpm to 13.44±0.82% at 90 rpm, and Net efficiency (η net) similarly decreased from 25.60±4.75% and 22.45±1.64% at 45 rpm and 60 rpm to 16.97±1.33% at 90 rpm. Although the rate of fat oxidation was not changed in all pedaling frequency, the rate of carbohydrate oxidation gradually rose with increase in pedaling frequency, the rate of carbohydrate oxidation at 90 rpm significantly (p

We investigated the effects of familiarization on the reliability of gross efficiency (GE) and lower-limb electromyography (EMG-rms) of adults and adolescents. We also evaluated the relationship between inter-test differences in GE and EMG-rms. Nine adult and nine adolescent cyclists performed three 10 min cycling tests at 50% of peak power output, separated by 48 h. Forty-five minutes familiarization visits were performed 24 h after each test. No differences were found across the tests for adult cyclists’ GE or EMG-rms, with Coefficient of Variation (CV%) ranging from 2.6 to 2.9% (GE) and 4.3 to 7.4%. Among adolescents, there was an increase in GE between tests 1 and 2 (p 0.05) between the inter-test differences of GE and EMG-rms. GE can be reliably determined; however, adolescents require two exposures to cycling. Without familiarization, adolescent EMG-rms is more variable than adults and would require larger samples to establish differences. The weak relationships between inter-test EMG-rms and inter-test GE questions the link between muscle activation and GE changes.

Our purpose was to determine if using an individual's power-specific gross efficiency improves the accuracy of estimating energy expenditure from cycling power. 30 subjects performed a graded cycling test to develop 4 gross efficiencies: individual power-specific gross efficiencies, a group mean power-specific gross efficiency, individual fixed gross efficiencies, and a group mean fixed gross efficiency. Energy expenditure was estimated from power using these different gross efficiencies and compared to measured energy expenditure during moderate- and hard-intensity constant-power and 2 variable-power cycling bouts. Estimated energy expenditures using individual or group mean power-specific gross efficiencies were not different from measured energy expenditure across all cycling bouts (p0.05). To examine the intra-individual variability of the estimates, absolute difference scores (absolute value of estimated minus measured energy expenditure) were compared, where values closer to zero represent more accurate individual estimates. The absolute difference score using individual power-specific gross efficiencies was significantly lower compared to the other gross efficiencies across all cycling bouts (p0.01). Significant and strong correlations (r≥0.97, p0.001) were found across all cycling bouts between estimated and measured energy expenditures using individual power-specific gross efficiencies. In conclusion, using an individual's power-specific gross efficiency significantly improves their energy expenditure estimate across different power outputs.

PURPOSE: This study aimed to examine the metabolic responses and pacing strategies during the performance of successive sprint time trials (STTs) in cross-country skiing.METHODS: Ten well-trained male cross-country skiers performed four self-paced 1300-m STTs on a treadmill, each separated by 45 min of recovery. The simulated sprint time trial (STT) course was divided into three flat (1°) sections (S1, S3, and S5) involving the double poling subtechnique interspersed with two uphill (7°) sections (S2 and S4) involving the diagonal stride subtechnique. Treadmill velocity and V˙O2 were monitored continuously, and gross efficiency was used to estimate the anaerobic energy supply.RESULTS: The individual trial-to-trial variability in STTs performance time was 1.3%, where variations in O2 deficit and V˙O2 explained 69% (P < 0.05) and 11% (P > 0.05) of the variation in performance. The first and the last STTs were equally fast (228 ± 10 s) and ~1.3% faster than the second and the third STTs (P < 0.05). These two fastest STTs were associated with a 14% greater O2 deficit (P < 0.05), whereas the average V˙O2 was similar during all four STTs (86% ± 3% of V˙O2max). Positive pacing was used throughout all STTs, with significantly less time spent on the first than second course half. In addition, metabolic rates were substantially higher (~30%) for uphill than for flat skiing, indicating that pacing was regulated to the terrain.CONCLUSIONS: The fastest STTs were characterized primarily by a greater anaerobic energy production, which also explained 69% of the individual variation in performance. Moreover, the skiers used positive pacing and a variable exercise intensity according to the course profile, yielding an irregular distribution of anaerobic energy production.

[English] The aim of this study was to determine the effects of high- and low-cadence interval training on the freely chosen cadence (FCC) and performance in endurance-trained cyclists. Sixteen male endurance-trained cyclists completed a series of submaximal rides at 60% maximal power (Wmax) at cadences of 50, 70, 90, and 110 r·min−1, and their FCC to determine their preferred cadence, gross efficiency (GE), rating of perceived exertion, and crank torque profile. Performance was measured via a 15-min time trial, which was preloaded with a cycle at 60% Wmax. Following the testing, the participants were randomly assigned to a high-cadence (HC) (20% above FCC) or a low-cadence (LC) (20% below FCC) group for 18 interval-based training sessions over 6 weeks. The HC group increased their FCC from 92 to 101 r·min−1 after the intervention (p = 0.01), whereas the LC group remained unchanged (93 r·min−1). GE increased from 22.7% to 23.6% in the HC group at 90 r·min−1 (p = 0.05), from 20.0% to 20.9% at 110 r·min−1 (p = 0.05), and from 22.8% to 23.2% at their FCC. Both groups significantly increased their total distance and average power output following training, with the LC group recording a superior performance measure. There were minimal changes to the crank torque profile in both groups following training. This study demonstrated that the FCC can be altered with HC interval training and that the determinants of the optimal cycling cadence are multifactorial and not completely understood. Furthermore, LC interval training may significantly improve time-trial results of short duration as a result of an increase in strength development or possible neuromuscular adaptations. [French] Cette étude se propose de déterminer les effets d’un entraînement par intervalle à haute et à basse cadence sur la cadence librement choisie (FCC) et la performance chez des cyclistes entraînés en endurance. Seize cyclistes masculins entraînés en endurance participent à une série de courses sous-maximales sollicitant 60 % de la Wmax à des cadences de 50, 70, 90, 110 rpm et à leur FCC afin de déterminer leur cadence préférée, le rendement brut (GE), l’intensité de l’effort perçu (RPE) et le profil du moment de force sur la manivelle. On mesure la performance au moyen d’un contre-la-montre de 15 min conditionné au préalable par une course à 60 % de la Wmax. À la suite de l’évaluation, on répartit aléatoirement les participants dans les groupes à haute (HC, 20 % > FCC) et à basse (HC, 20 % < FCC) cadence pour 18 séances d’entraînement par intervalle en 6 semaines. Le groupe HC accroit (p = 0,01) sa FCC de 92 à 101 rpm à la fin de la période d’intervention tandis que le groupe LC n’enregistre pas de modification (93 rpm). Le GE passe de 22,7 % à 23,6 % dans le groupe HC à 90 rpm (p = 0,05) et de 20,0 % à 20,9 % à 110 rpm (p = 0,05) et de 22,8 % à 23,2 % à sa FCC. Les deux groupes améliorent significativement leur distance totale; le groupe LC améliore sa puissance moyenne et présente une performance supérieure. On observe à la suite de la période d’intervention des modifications minimes du profil du moment de force sur la manivelle dans les deux groupes. D’après cette étude, on peut modifier la FCC par un entraînement par intervalle de type HC, mais on ne maîtrise pas totalement les multiples facteurs de la cadence optimale à vélo. De plus, un entraînement par intervalle de type LC peut améliorer significativement la performance au contre-la-montre de brève durée; cette amélioration est possiblement due à l’augmentation de la force ou à des adaptations neuromusculaires. [Traduit par la Rédaction]

Carlsson, M, Carlsson, T, Wedholm, L, Nilsson, M, Malm, C, and Tonkonogi, M. Physiological demands of competitive sprint and distance performance in elite female cross-country skiing. J Strength Cond Res 30(8): 2138-2144, 2016-The purpose was to investigate the relationship between elite females' competitive performance capability in sprint and distance cross-country skiing and the variables of gross efficiency (GE), work rate at the onset of blood-lactate accumulation (OBLA4mmol), maximal oxygen uptake (V[Combining Dot Above]O2max), maximal speed (Vmax), and peak upper-body oxygen uptake (V[Combining Dot Above]O2peak). Ten elite female cross-country skiers (age 24.5 ± 2.8 years) completed treadmill roller-skiing tests to determine GE, OBLA4mmol, and V[Combining Dot Above]O2max using the diagonal-stride technique as well as Vmax and V[Combining Dot Above]O2peak using the double-poling technique. International Ski Federations ranking points for sprint (FISsprint) and distance (FISdist) races were used as competitive performance data. There were correlations between the FISsprint and the V[Combining Dot Above]O2max expressed absolutely (p = 0.0040), Vmax (p = 0.012), and V[Combining Dot Above]O2peak expressed absolutely (p0.001) and as a simple ratio-standard (p = 0.049). The FISdist were correlated with OBLA4mmol (p = 0.048), V[Combining Dot Above]O2max expressed absolutely (L·min) (p = 0.015) and as a simple ratio-standard (p = 0.046), and V[Combining Dot Above]O2peak expressed absolutely (p = 0.036) and as a simple ratio-standard (ml·min·kg) (p = 0.040). The results demonstrate that the physiological abilities reflected by V[Combining Dot Above]O2max and V[Combining Dot Above]O2peak are indicators of competitive sprint and distance performance in elite female cross-country skiing. In addition, the ability to generate a high Vmax indicates the performance in sprint races, whereas the skier's OBLA4mmol reflects the performance capability in distance races. Based on the results, when evaluating the performance capacity of elite female cross-country skiers, it is recommended to use physiological variables that reflect competitive performance.

The purposes of the current study were to 1) test if the hinge position in the binding of skating skis has an effect on gross efficiency or cycle characteristics and 2) investigate whether hinge positioning affects synergistic components of the muscle activation in six lower leg muscles. Eleven male skiers performed three 4-min sessions at moderate intensity while cross-country ski-skating and using a klapskate binding. Three different positions were tested for the binding’s hinge, ranging from the front of the first distal phalange to the metatarsal-phalangeal joint. Gross efficiency and cycle characteristics were determined, and the electromyographic (EMG) signals of six lower limb muscles were collected. EMG signals were wavelet transformed, normalized, joined into a multi-dimensional vector, and submitted to a principle component analysis (PCA). Our results did not reveal any changes to gross efficiency or cycle characteristics when altering the hinge position. However, our EMG analysis found small but significant effects of hinge positioning on muscle coordinative patterns (P < 0.05). The changed patterns in muscle activation are in alignment with previously described mechanisms that explain the effects of hinge positioning in speed-skating klapskates. Finally, the within-subject results of the EMG analysis suggested that in addition to the between-subject effects, further forms of muscle coordination patterns appear to be employed by some, but not all participants. Copyright: © 2016 Bolger et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

Purpose:Manufacturers of uncoupled cycling cranks claim that their use will increase economy of motion and gross efficiency. Purportedly, this occurs by altering the muscle-recruitment patterns contributing to the resistive forces occurring during the recovery phase of the pedal stroke. Uncoupled cranks use an independent-clutch design by which each leg cycles independently of the other (ie, the cranks are not fixed together). However, research examining the efficacy of training with uncoupled cranks is equivocal. The purpose of this study was to determine the effect of short-term training with uncoupled cranks on the performance-related variables economy of motion, gross efficiency, maximal oxygen uptake (VO2max), and muscle-activation patterns.Methods:Sixteen trained cyclists were matched-paired into either an uncoupled-crank or a normal-crank training group. Both groups performed 5 wk of training on their assigned cranks. Before and after training, participants completed a graded exercise test using normal cranks. Expired gases were collected to determine economy of motion, gross efficiency, and VO2max, while integrated electromyography (iEMG) was used to examine muscle-activation patterns of the vastus lateralis, biceps femoris, and gastrocnemius.Results:No significant changes between groups were observed for economy of motion, gross efficiency, VO2max, or iEMG in the uncoupled- or normal-crank group.Conclusions:Five weeks of training with uncoupled cycling cranks had no effect on economy of motion, gross efficiency, muscle recruitment, or VO2max compared with training on normal cranks.

We purposed to study energy expenditure, power output and gross efficiency during kayak ergometer exercise in 12 elite sprint kayakers. 6 males (age 24.2±4.8 years, height 180.4±4.8 cm, body mass 79.7±8.5 kg) and 6 females (age 24.3±4.5 years, height 164.5±3.9 cm, body mass 65.4±3.5 kg), performed an incremental intermittent protocol on kayak ergometer with V˙O 2 and blood lactate concentration assessment, a non-linear increase between power output and energy expenditure being observed. Paddling power output, energy expenditure and gross efficiency corresponding to V˙O 2 max averaged 199.92±50.41 W, 75.27±6.30 ml.kg − 1 .min − 1 , and 10.10±1.08%. Male kayakers presented higher V˙O 2 max, power output and gross efficiency at the V˙O 2 max, and lower heart rate and maximal lactate concentration than females, but no differences were found between genders regarding energy expenditure at V˙O 2 max. Aerobic and anaerobic components of energy expenditure evidenced a significant contribution of anaerobic energy sources in sprint kayak performance. Results also suggested the dependence of the gross efficiency on the changes in the amount of the aerobic and anaerobic contributions, at heavy and severe intensities. The inter-individual variance of the relationship between energy expenditure and the corresponding paddling power output revealed a relevant tracking for females (FDγ=0.73±0.06), conversely to the male group (FDγ=0.27±0.08), supporting that some male kayakers are more skilled in some paddling intensities than others.

Exercise efficiency at low power outputs, energetically comparable to daily living activities, can be influenced by homeostatic perturbations (e.g., weight gain/loss). However, an appropriate efficiency calculation for low power outputs used in these studies has not been determined. Fifteen active subjects (seven females, eight males) performed 14, 5-min cycling trials: two types of seated rest (cranks vertical and horizontal), passive (motor-driven) cycling, no-chain cycling, no-load cycling, cycling at low (10, 20, 30, 40 W), and moderate (50, 60, 80, 100, 120 W) power outputs. Mean delta efficiency was 57% for low power outputs compared to 41.3% for moderate power outputs. Means for gross (3.6%) and net (5.7%) efficiencies were low at the lowest power output. At low power outputs, delta and work efficiency values exceeded theoretical values. In conclusion, at low power outputs, none of the common exercise efficiency calculations gave values comparable to theoretical muscle efficiency. However, gross efficiency and the slope and intercept of the metabolic power vs mechanical power output regression provide insights that are still valuable when studying homeostatic perturbations.

HOPKER, J. G., S. A. JOBSON, H. C. GREGSON, D. COLEMAN, and L. PASSFIELD. Reliability of Cycling Gross Efficiency Using the Douglas Bag Method. Med. Sci. Sports Exerc., Vol. 44, No. 2, pp. 290–296, 2012. Purpose: The aim of this study was to establish the reliability of gross efficiency (GE) measurement (the ratio of mechanical power input to metabolic power output, expressed as a percentage) using the Douglas bag method. Methods: The experiment was conducted in two parts. Part 1 examined the potential for errors in the Douglas bag method arising from gas concentration analysis, bag residual volume, and bag leakage or gas diffusion rates. Part 2 of this study examined the within-subject day-to-day variability of GE in 10 trained male cyclists using the Douglas bag method. Participants completed three measurements of GE on separate days at work rates of 150, 180, 210, 240, 270, and 300 W. Results: The results demonstrate that the reliability of gas sampling is high with a coefficient of variation (CV) G0.5% for both O2 and CO2. The bag residual volume CV was E15%, which amounts to +0.4 L. This could cause the largest error, but this can be minimized by collecting large gas sample volumes. For part 2, a mean CV of 1.5% with limits of agreement of +0.6% in GE units, around a mean GE of 20.0%, was found. Conclusions: The Douglas bag method of measuring expired gases and GE was found to have very high reliability and could be considered the gold-standard approach for evaluating changes in GE. Collecting larger expired gas samples minimizes

Cyclist position on his bicycle and individual anthropometric parameters are very important to optimise pedalling biomechanics (Bini et al. 2011). Postural imbalance can lead to increase joint stre...

The purpose of the present study was to examine the effect of frequency on efficiency and performance during G3 roller ski skating. Eight well-trained male cross-country skiers performed three submaximal 5-min speeds (10, 13, and 16 km/h) and a time-to-exhaustion (TTE) performance (at 20 km/h) using the G3 skating technique using freely chosen, high, and low frequency at all four speeds. All tests were done using roller skis on a large treadmill at 5% incline. Gross efficiency (GE) was calculated as power divided by metabolic rate. Power was calculated as the sum of power against frictional forces and power against gravity. Metabolic rate was calculated from oxygen consumption and blood lactate concentration. Freely chosen frequency increased from 60 to 70 strokes/min as speed increased from 10 to 20 km/h. GE increased with power. At high power (20 km/h performance test), both efficiency and performance were significantly reduced by high frequency. In regard to choice of frequency during G3 roller ski skating, cross-country skiers seems to be self-optimized both in relation to energy saving (efficiency) and performance (TTE).

Anaerobic capacity (AnC) can be estimated by subtracting VO 2 consumed from VO 2 demand, which can be estimated from multiple submaximal exercise bouts or by gross efficiency (GE), requiring one submaximal bout. This study compares AnC using the MAOD and GE method. The precision of estimated VO 2 demand and AnC, determined by MAOD using 3 power output – VO 2 regressions, based on VO 2 from min 8–10 (10 − Y), during min 4 without (4 − Y) and with forced y-intercept (4+Y), and from GE was evaluated by the 95% confidence interval (CI). Well-trained males (n=15) performed submaximal exercise tests to establish VO 2 demand with the MAOD and GE method. To determine AnC subjects completed a constant power output trial. The 3 MAOD procedures and GE method had no significant difference for VO 2 demand and AnC. The 4+Y MAOD procedure and GE method resulted in a smaller 95% CI of VO 2 demand and AnC than the 10 − Y ( P

''The present study aimed to test the influence of the pedalling technique on the occurrence of muscular fatigue and on the energetic demand during prolonged constant-load cycling exercise. Subjects performed two prolonged (45 min) cycling sessions at constant intensity (75% of maximal aerobic power). In a random order, participants cycled either with their preferred technique (PT) during one session or were helped by a visual force-feedback to modify their pedalling pattern during the other one (FB). Index of pedalling effectiveness was significantly (P

Purpose: Because cycling is an extreme endurance sport, energy saving and therefore efficiency is of importance for performance. It is generally believed that gross efficiency (GE) is affected by pedaling technique. A measurement of pedaling technique has traditionally been done using force effectiveness ratio (FE; ratio of effective force and total force). The aim of the present study was to investigate the relationship among GE, FE, and a new technique parameter, dead center (DC) size in competitive cyclists. Method: Twenty-one competitive cyclists cycled for 10 min at approximately 80% V?O2max at a freely chosen cadence (FCC). GE, FE ratio, and DC size were calculated from oxygen consumption and propulsive force recordings. Results: Mean work rate was 279 W, mean FCC was 93.1 rpm, and mean GE was 21.7%. FE was 0.47 and 0.79 after correction for inertial forces; DC was 27.3% and 25.7%, respectively. DC size correlated better with GE (r = 0.75) than with the FE ratio (r = 0.50). Multiple regressions revealed that DC sizewas the only significant (P = 0.001) predictor for GE. Interestingly, DC size and FE ratio did not correlate with each other. Conclusions: DC size is a pedaling technique parameter that is closely related to energy consumption. To generate power evenly around the whole pedal, revolution may be an important energy-saving trait

Technique and energy saving are two variables often considered as important for performance in cycling and related to each other. Theoretically, excellent pedalling technique should give high gross efficiency (GE). The purpose of the present study was to examine the relationship between pedalling technique and GE. 10 well-trained cyclists were measured for GE, force effectiveness (FE) and dead centre size (DC) at a work rate corresponding to ~75% of VO2max during level and inclined cycling, seat adjusted forward and backward, at three different cadences around their own freely chosen cadence (FCC) on an ergometer. Within subjects, FE, DC and GE decreased as cadence increased (p

Purpose Athletes are trained to choose the pace which is perceived to be correct during a specific effort, such as the 1500-m speed skating competition. The purpose of the present study was to "override" self-paced (SP) performance by instructing athletes to execute a theoretically optimal pacing profile.Methods Seven national-level speed-skaters performed a SP 1500-m which was analysed by obtaining velocity (every 100 m) and body position (every 200 m) with video to calculate total mechanical power output. Together with gross efficiency and aerobic kinetics, obtained in separate trials, data were used to calculate aerobic and anaerobic power output profiles. An energy flow model was applied to SP, simulating a range of pacing strategies, and a theoretically optimal pacing profile was imposed in a second race (IM).Results Final time for IM was similar to 2 s slower than SP. Total power distribution per lap differed, with a higher power over the first 300 m for IM (637.0 (49.4) vs 612.5 (50.0) W). Anaerobic parameters did not differ. The faster first lap resulted in a higher aerodynamic drag coefficient and perhaps a less effective push-off.Conclusion Experienced athletes have a well-developed performance template, and changing pacing strategy towards a theoretically optimal fast start protocol had negative consequences on speed-skating technique and did not result in better performance.

The purpose of this study was to investigate asymmetry of muscle activation in participants with different levels of experience and performance with cycling. Two separate experiments were conducted, one with nine cyclists and one with nine non-cyclists. The experiments involved incremental maximal and sub-maximal constant load cycling tests. Bilateral surface electromyography (EMG) and gross and net muscle efficiency were assessed. Analyses of variance in mixed linear models and t-tests were conducted. The cyclists in Experiment 1 presented higher gross efficiency (P0.05), whereas net efficiency did not differ between the two experiments (21.3 ± 1.4% and 19.8 ± 1.0% for cyclists and non-cyclists, respectively). The electrical muscle activity increased significantly with exercise intensity regardless of leg preference in both experiments. The coefficient of variation of EMG indicated main effects of leg in both experiments. The non-preferred leg of non-cyclists (Experiment 2) presented statistically higher variability of muscle activity in the gastrocnemius medialis and vastus lateralis. Our findings suggest similar electrical muscle activity between legs in both cyclists and non-cyclists regardless of exercise intensity. However, EMG variability was asymmetric and appears to be strongly influenced by exercise intensity for cyclists and non-cyclists, especially during sub-maximal intensity. Neural factors per se do not seem to fully explain previous reports of pedalling asymmetries.

The purpose of this study was to determine the effect of "Pose" cycling (a combination of specific bicycle setup and pedaling technique) on metabolic efficiency and pedaling mechanics. Eighteen recreational cyclists were tested for efficiency and pedaling mechanics during steady-state cycling (90% gas-exchange threshold) using two different bicycle setups (preferred and "Pose") and three different pedaling rates (70, 90 and 110 rpm). Nine of the participants underwent a coaching intervention (4 × 1 h) consisting of drills based on the "Pose" instruction manual. The remaining nine participants did not receive an intervention. All participants were tested before and after the intervention period. Analyses of variance were performed to test the independent effects of the "Pose"-specific bicycle setup and pedaling technique on gross efficiency and pedaling mechanics. The "Pose"-specific bicycle setup resulted in increased gross efficiency at each pedaling rate compared to the participants' preferred bicycle position (P < 0.05). This increase in efficiency was accompanied by a significant increase in trunk frontal area (P < 0.05). The coaching intervention resulted in decreased gross efficiency at 110 rpm (P < 0.05); at this pedaling rate the intervention resulted in a slight increase in the non-muscular contribution to pedal power in the experimental group and a decrease in the control group. The combination of changed bicycle setup and pedaling technique had no effect on gross efficiency and only small effects on pedaling mechanics. Our findings add to a growing body of literature that short-term interventions in pedaling technique can change pedaling mechanics but do not improve efficiency during steady-state cycling. Dr Nicholas Romanov

The aim of this study was to examine differences in cycling efficiency between competitive male and female cyclists. Thirteen trained male (mean ± SD: 34 ± 8 yr, 74.1 ± 6.0 kg, Maximum Aerobic Power (MAP) 414 ± 40 W, VO2max 61.3 ± 5.4 ml·kg-1·min-1) and 13 trained female (34 ± 9 yr, 60.1 ± 5.2 kg, MAP 293 ± 22 W, VO2max 48.9 ± 6.1 ml·kg-1·min-1) competitive cyclists completed a cycling test to ascertain their gross efficiency (GE). Leg and lean leg volume of all cyclists was also measured. Calculated GE was significantly higher in female cyclists at 150W (22.5 ± 2.1 vs 19.9 ± 1. 8%; p < 0.01) and 180W (22.3 ± 1.8 vs 20.4 ± 1.5%; p = 0.01). Cadence was not significantly different between the groups (88 ± 6 vs 91 ± 5 rev·min-1). Lean leg volume was significantly lower for female cyclists (4.04 ± 0.5 vs 5.51 ± 0.8 dm3; p < 0.01) and was inversely related to GE in both groups at 150 and 180W (r = -0.59 and -0.58; p < 0.05). Lean leg volume was shown to account for the differences in GE between the males and females. During an "unloaded" pedalling condition, male cyclists had a significantly higher O2 cost than female cyclists (1.0 ± 0.1 vs 0.7 ± 0.1 L·min-1; p < 0.01), indicative of a greater non-propulsive cost of cycling. These results suggest that differences in efficiency between trained male and female cyclists can be partly accounted for by sex-specific variation in lean leg volume

There has been much debate in the recent scientific literature regarding the possible ability to increase gross efficiency in cycling via training. Using cross-sectional study designs, researchers have demonstrated no significant differences in gross efficiency between trained and untrained cyclists. Reviewing this literature provides evidence to suggest that methodological inadequacies may have played a crucial role in the conclusions drawn from the majority of these studies. We present an overview of these studies and their relative shortcomings and conclude that in well-controlled and rigorously designed studies, training has a positive influence upon gross efficiency. Putative mechanisms for the increase in gross efficiency as a result of training include, muscle fibre type transformation, changes to muscle fibre shortening velocities and changes within the mitochondria. However, the specific mechanisms by which training improves gross efficiency and their impact on cycling performance remain to be determined.

The purpose of this study was to examine the effect of regulation of work rate, computer controlled versus controlled by the subject, on the relationship between work rate, freely chosen pedal rate (FCC) and gross efficiency. Eighteen male cyclists participated in the study. One group, freely cycling (FC) on a competition bike mounted on an electromagnetic roller, could use gearing and cadence to achieve each work rate. The other group (EC) was cycling on an ergometer which enables a constant work rate, independent of cadence. Subjects performed an increasing work rate protocol from 100 W up to exhaustion. We found a strong interaction between group and work rate on cadence (P < 0.001). In the FC group, work rate affected cadence (P < 0.001), increasing from 72 rpm at 100 W to 106 rpm at 350 W. For the EC group, no work rate effect was present (average FCC 92 rpm). Gross efficiency increased with work rate for both groups. The efficiency-cadence relationship was strongly affected by the protocol. At a given work rate, very similar efficiency values were obtained at highly different cadences. The discrepancy in the FCC-work rate relationship between the EC group and the FC group may be related to the manner in which one can regulate work rate. FCC depends not only on work rate but is also affected considerably by the manner in which the work rate can be controlled by cadence. This finding may have important implications for the interpretation of the preferred pedaling rate, especially how this is related to optimizing metabolic cost.

Tail pipe emission reduction, increased use of renewable fuels and efficient supply of auxiliary power for road vehicles using fuel cells have been the main drivers of the European project BIOFEAT (biodiesel fuel processor for a fuel cell auxiliary power unit for a vehicle). Within the project a biodiesel fuelled heat integrated fuel processor for 10 kW e capacity has been designed and constructed. Demonstration tests showed a high quality reformate with less than 10 ppm of CO and a gross efficiency of 87%.

This report describes the changes in physiological capacity of a heavy-weight rower who obtained seven medals in World Championships and Olympic Games. The investigation was carried out over the last 6 years of the rower’s international competition career in comparison with peer champions, and the following 4 years. Over the first period, maximal oxygen uptake ( $$ \dot{V}{\text{O}}_{2\max } $$ ) remained above 6 l min−1 which is an outstanding value. The training load measured over the last 18 months of the period increased from 119 to 142 km wk−1 of rowing. Four years after the international competition period, $$ \dot{V}{\text{O}}_{2\max } $$ had only declined by 3.6% although the training load had declined by 35%. These data suggest that the ability of this rower to compete at top level for years was related to ability to maintain an outstanding $$ \dot{V}{\text{O}}_{2\max } $$ . Gross efficiency and ability to rely on anaerobic glycolysis did not emerge as relevant factors.

The purpose of this study was to determine whether there is a causal relationship between pedalling “circularity” and cycling efficiency. Eleven trained cyclists were studied during submaximal cycling. Variables recorded included gross and delta efficiency and the ratio of minimum to peak torque during a duty cycle. Participants also completed a questionnaire about their training history. The most notable results were as follows: gross efficiency (r = -0.72, P < 0.05 at 250 W) was inversely correlated with the ratio of minimum to peak torque, particularly at higher work rates. There was a highly significant inverse correlation between delta efficiency and average minimum torque at 200 W (r = -0.76, P < 0.01). Cycling experience was positively correlated with delta efficiency and gross efficiency, although experience and the ratio of minimum to peak torque were not related. These results show that variations in pedalling technique may account for a large proportion of the variation in efficiency in trained cyclists. However, it is also possible that some underlying physiological factor influences both. Finally, it appears that experience positively influences efficiency, although the mechanism by which this occurs remains unclear.

Perturbations in body weight have been shown to affect energy expenditure and efficiency during physical activity. The separate effects of weight loss and exercise training on exercise efficiency or the proportion of energy derived from fat oxidation during physical activity, however, are not known. The purpose of this study was to determine the separate and combined effects of exercise training and weight loss on metabolic efficiency, economy (EC), and fat oxidation during steady-state moderate submaximal exercise. Sixty-four sedentary older (67 ± 0.5 yr) overweight to obese (30.7 ± 0.4 kg/m2) volunteers completed 4 mo of either diet-induced weight loss (WL; n = 11), exercise training (EX; n = 36), or the combination of both interventions (WLEX; n = 17). Energy expenditure, gross efficiency (GE), EC, and proportion of energy expended from fat (EF) were determined during a 1-h submaximal (50% of peak aerobic capacity) cycle ergometry exercise before the intervention and at the same absolute work rate after the intervention. We found that EX increased GE by 4.7 ± 2.2%. EC was similarly increased by 4.2 ± 2.1% by EX. The addition of concomitant WL to EX (WLEX) resulted in greater increases in GE (9.0 ± 3.3%) compared with WL alone but not compared with EX alone. These effects remained after adjusting for changes in lean body mass. The proportion of energy derived from fat during the bout of moderate exercise increased with EX and WLEX but not with WL. From these findings, we conclude that exercise training, either alone or in combination with weight loss, increases both exercise efficiency and the utilization of fat during moderate physical activity in previously sedentary, obese older adults. Weight loss alone, however, significantly improves neither efficiency nor utilization of fat during exercise.

We assessed the possible association between variants of the genes encoding for the angiotensin-converting enzyme ( ACE) and alpha-actinin-3 ( ACTN3) (both individually and combined) and several endurance phenotypic traits, e.g., peak power output (PPO), ventilatory (VT) and respiratory compensation threshold (RCT), among others, in professional road cyclists and sedentary controls (n = 46 each). We applied an ANCOVA test using the aforementioned phenotype traits as dependent variables, ACE and/or ACTN3 genotype as the fixed (independent) factor and age and body mass as covariates. We only found a significant genotype effect with no concomitant covariate effect for ACTN3, with cyclists who were not alpha-actinin-3 deficient (RR + RX genotypes) having higher PPO and VT values than their XX counterparts (mean [SEM]: 7.4 (0.1) vs. 7.1 (0.1) W/kg, p = 0.035; and 4.5 (0.1) vs. 4.3 (0.1) W/kg, p = 0.029, respectively). Cyclists with an "extreme" ACTN3 and ACE genotype combination, i.e., most strength/power oriented (DD + RR/RX), had higher RCT values than those with the "intermediate" combinations (II + RX/RR, p = 0.036; and DD + XX, p = .0004) but similar to those with the most endurance oriented genotype (II + XX). No significant differences (p > 0.05) were found in controls. In summary, in world-class cyclists, we only found an association between ACTN3 genotypes and VT and PPO, and between ACTN3/ACE genotype combinations and RCT. 1.589 JCR (2009) Q2, 27/73 Sport sciences UEM

The aim of this study was to examine the claim that reductions of 8 – 18% in submaximal oxygen consumption ([Vdot]O2) could be due to changing components on a Monark ergometer, from standard pedals without toe-clips or straps (flat pedals) to racing pedals of that era, which included toe-clips and straps (toe-clip pedals). This previously untested assertion was evaluated using 11 males (mean age 22.3 years, s = 1.2; height 1.82 m, s = 0.07; body mass 82.6 kg, s = 8.8) who completed four trials in a randomized, counterbalanced order at 60 rev · min−1 on a Monark cycle ergometer. Two trials were completed on flat pedals and two trials on toe-clip pedals. The Douglas bag method was used to assess [Vdot]O2 and gross efficiency during successive 5-min workloads of 60, 120, 180, and 240 W. The mean [Vdot]O2 was 2.1% higher for toe-clip pedals than flat pedals and there was a 99% probability that toe-clip pedals would not result in an 8% lower [Vdot]O2. These results indicate that toe-clip pedals do not...

The effects of energy supplementation on Leu utilization in growing steers were evaluated in 2 experiments by using 6 ruminally cannulated Holstein steers. In Exp. 1, steers (initial BW = 150 +/- 7 kg) were limit-fed (2.3 kg of DM/d) a diet based on soybean hulls and received a basal ruminal infusion of 100 g of acetate/d, 75 g of propionate/d, and 75 g of butyrate/d, as well as abomasal infusions of 200 g of glucose/d and a mixture (215 g/d) containing all essential AA except Leu. Treatments were arranged as a 3 x 2 factorial, with 3 amounts of Leu infused abomasally (0, 4, and 8 g/d) and supplementation of diets with 2 amounts of energy (0 and 1.9 Mcal/d of GE). Supplemental energy was supplied by ruminal infusion of 100 g of acetate/ d, 75 g of propionate/d, and 75 g of butyrate/d, as well as abomasal infusion of 200 g of glucose/d to provide energy to the animal without affecting the microbial protein supply. When no supplemental energy was provided, Leu supplementation increased N balance, with no difference between 4 and 8 g/d of Leu (24.5, 27.0, and 27.3 g/d for 0, 4, and 8 g/d of Leu), but when additional energy was supplied, N retention increased linearly in response to Leu (25.6, 28.5, and 31.6 g/d for 0, 4, and 8 g/d of Leu; Leu x energy interaction, P = 0.06). The changes in N balance were the result of changes in urinary N excretion. The greater Leu retentions in response to energy supplementation when Leu was the most limiting nutrient indicate that energy supplementation improved the true efficiency of Leu utilization. In addition, supplemental energy increased the gross efficiency of Leu utilization when the Leu supply was not limiting by increasing the maximal rates of protein deposition. Experiment 2 was similar to Exp. 1, but steers had an initial BW of 275 +/- 12 kg and were limit-fed at 3.6 kg of DM/d. Retention of N was not affected (P = 0.22) by Leu supplementation, indicating that Leu did not limit protein deposition. Energy supply increased N retention (P < 0.01) independently of Leu supplementation (33.0 vs. 27.8 g/d). Overall, energy supplementation improved Leu utilization by modestly increasing N retention when Leu was limiting and by increasing the ability of steers to respond to the greatest amount of supplemental Leu. We conclude from these results that the assumption of a constant efficiency of AA utilization is unlikely to be appropriate for growing steers.

This study analysed muscular, mechanical and physiological parameters using a circular chainring (CC) and a non circular Osymetric chainring (OC). OC was characterized by the use of 11 lowerradius during top and bottom dead cerner and a higher radius during downstroke and upstroke phases. Twelve triathleres performed (i) an 8 min submaximal test and (ii) Iwo 8 s maximal sprint rests. Gross efficiency was calculated during the submaximal rest. InSlantaneous external force and pedalling rate 'vere recorded and the instantaneous nel crank torque was calculated during both tests. Lower limb muscles coordination pattern (timing and magnirude) were also recorded. During the submaximal rest, the only significant differences were the lower net crank torque or OC vs. CC at (f and I gOa and the higher nel crank torque of OC vs. CC at 90° (P < 0.(5). Concerning the sprint test, the only significant difference was the higher burst duration of the biceps femoris muscle with OC (P < 0.05). Present results indicate that OC facilitated mechanically the foot path at 0° and 1800 Nevertheless. this mechanical effect did nOI seem to be sufficient to improve performance since the muscles coordination pattern was not modified.

The effects of the fungus, Trichoderma harzanium, treated cassava waste on milk quantity and quality were investigated in a completely randomized design model with twelve lactating West African dwarf does. Goats were fed the experimental diets containing O (A), 20 (B), 30 (C) and 40% (D) Trichoderma treated cassava waste during a 13 week lactation trial. The results revealed significant differences in milk quantity and quality. The highest milk yield was recorded for diet D followed closely by diets C, B and A in that order. Inclusion of fungus treated cassava waste resulted in significant increasing milk fat, protein, solids not fat (SNF), and total solids. While the inclusion had little effect on milk pH and specific gravity. The yield of 40% fat corrected milk (FCM) and gross efficiency of milk increased significantly (P < 0.05) by the addition of fungus treated cassava waste in the diet. In conclusion, the addition of Trichoderma treated cassava waste was beneficial to lactating West African dwarf goats.

The purpose of this study was to determine economy and mechanical efficiency in men and women during both arm cranking (AC) and leg cycling (LC) at 70%, 85%, 100%, and 115% of mode-specific ventilatory threshold (T(vent)). Recreationally active men (n=9) and women (n=9) with similar values for %VO2peak at T(vent) served as subjects. All subjects performed 5 min of exercise at each intensity of 70%, 85%, 100%, and 115% of T(vent) for both AC and LC. Economy was expressed as W/L/min. Gross efficiency (GE) was determined as the ratio of work accomplished to total energy expended (%). Delta efficiency (DE) was determined as the ratio of delta work accomplished to delta energy expended (%). Economy and efficiency during LC were greater than during AC in men and women. During AC or LC exercise, no sex differences were found in either economy (P=0.93 for AC, 0.98 for LC), GE (P=0.88 for AC, 0.75 for LC), or DE (P=0.57 for AC, 0.51 for LC). These findings indicate that men and women show similar economy and efficiency during both AC and LC exercise when subjects have similar %VO2peak at Tvent.

WOS: 000349331900010, PubMed ID: 25713670, The purpose of this study was to compare the effects of sprint interval training (SIT) and continuous endurance training (CET) on selected anthropometric, aerobic, and anaerobic performance indices as well as the blood lipid profile, inflammatory and muscle damage markers in healthy young males. Fifteen recreationally active male volunteers (age: 21.7 +/- 2.2 years, body mass: 83.0 +/- 8.0 kg, body height: 1.82 +/- 0.05 m) were divided into two groups according to their initial VO2max levels. Training programs were conducted 3 times per week for 7 weeks. The SIT program consisted of 4-6 Wingate anaerobic sprints with a 4.5 min recovery, while CET consisted of 30-50 min cycling at 60% VO2max. Biochemical, anthropometric and fitness assessments were performed both pre and post-intervention. Significant improvements in VO2max, anaerobic power and capacity, and VO2 utilization during the submaximal workout and significant decreases in body fat and in waist circumference after the intervention occurred in both SIT and CET groups. Significantly greater gross efficiency was measured in the CET group. No differences in the lipid profile or serum levels of inflammatory, myocardial and skeletal muscle damage markers were observed after the training period. The study results agree with the effectiveness of a 30 s all-out training program with a reduced time commitment for anthropometric, aerobic and anaerobic adaptation and eliminate doubts about its safety as a model.

Purpose: While a number of studies have investigated gross efficiency (GE) in laboratory conditions, few studies have analyzed it in field conditions. Therefore, the aim of this study was to analyze the effect of gradient and cadence on GE in field conditions. Methods: Thirteen trained cyclists (mean ± SD age 23.3 ± 4.1 y, stature 177.0 ± 5.5 cm, body mass 69.0 ± 7.2 kg, maximal oxygen uptake [V̇O2max] 68.4 ± 5.1 mL ∙ min–1 ∙ kg–1) completed an incremental graded exercise test to determine ventilatory threshold (VT) and 4 field trials of 6 min duration at 90% of VT on flat (1.1%) and uphill terrain (5.1%) with 2 different cadences (60 and 90 rpm). V̇O2 was measured with a portable gas analyzer and power output was controlled with a mobile power crank that was mounted on a 26-in mountain bike. Results: GE was significantly affected by cadence (20.6% ± 1.7% vs 18.1% ± 1.3% at 60 and 90 rpm, respectively; P < .001) and terrain (20.0% ± 1.5% vs 18.7% ± 1.7% at flat and uphill cycling, respectively; P = .029). The end-exercise V̇O2 was 2536 ± 352 and 2594 ± 329 mL/min for flat and uphill cycling, respectively (P = .489). There was a significant difference in end-exercise V̇O2 between 60 (2352 ± 193 mL/min) and 90 rpm (2778 ± 431 mL/min) (P < .001). Conclusions: These findings support previous laboratory-based studies demonstrating reductions in GE with increasing cadence and gradient that might be attributed to changes in muscle-activity pattern.

Previous research showed that gross efficiency (GE) declines during exercise and therefore influences the expenditure of anaerobic and aerobic resources.Purpose:To calculate the anaerobic work produced during cycling time trials of different length, with and without a GE correction.Methods:Anaerobic work was calculated in 18 trained competitive cyclists during 4 time trials (500, 1000, 2000, and 4000-m). Two additional time trials (1000 and 4000 m) that were stopped at 50% of the corresponding “full” time trial were performed to study the rate of the decline in GE.Results:Correcting for a declining GE during time-trial exercise resulted in a significant (P < .001) increase in anaerobically attributable work of 30%, with a 95% confidence interval of [25%, 36%]. A significant interaction effect between calculation method (constant GE, declining GE) and distance (500, 1000, 2000, 4000 m) was found (P < .001). Further analysis revealed that the constant-GE calculation method was different from the declining method for all distances and that anaerobic work calculated assuming a constant GE did not result in equal values for anaerobic work calculated over different time-trial distances (P < .001). However, correcting for a declining GE resulted in a constant value for anaerobically attributable work (P = .18).Conclusions:Anaerobic work calculated during short time trials (

Purpose:To reach top performance in cycling, optimizing distribution of energy resources is crucial. The purpose of this study was to investigate power output during 250-m, 500-m, and 1000-m cycling time trials and the characteristics of the adopted pacing strategy.Methods:Nine trained cyclists completed an incremental test and 3 time trials that they were instructed to finish as quickly as possible. Preceding the trials, peak power during short sprints (PPsprint) and gross efficiency (GE) were measured. During the trials, power output and oxygen consumption were measured to calculate the contribution of the aerobic and anaerobic energy sources. After the trial GE was measured again.Results:Peak power during all trials (PPTT) was lower than PPsprint. In the 250-m trial the PPTT was higher in the 1000-m trial (P = .008). The subjects performed a significantly longer time at high intensity in the 250-m than in the 1000-m (P = .029). GE declined significantly during all trials (P < .01). Total anaerobically attributable work was less in the 250-m than in the 500-m (P = .015) and 1000-m (P < .01) trials.Conclusion:The overall pacing pattern in the 250-m trial appears to follow an all-out strategy, although peak power is still lower than the potential maximal power output. This suggests that a true all-out pattern of power output may not be used in fixed-distance events. The 500-m and 1000-m had a more conservative pacing pattern and anaerobic power output reached a constant magnitude.

A design is presented for a modernized lignite-fired TPE-216M boiler for a highly efficient 225-MW power-generating unit, which can be installed at the Kharanorskaya state area power plant (Station No. 3). The boiler has a guaranteed gross efficiency of 92.5%, and satisfies modern ecological requirements: NOx concentration of less then 300 mg/m3 in the flue gases, owing to the high gross efficiency of the unit, which is no less than 40%, NOx emissions computed per 1 kW · h are reduced additionally by 10%, and the same applies to CO2 emissions. The temperature of the steam is raised from 545 to 565°C. A low-pressure water economizer, which is included in the heat diagram of the unit, is installed to lower the temperature of the exiting gases.