scholarly journals The First Lactate Threshold Is a Limit for Heavy Occupational Work

2020 ◽  
Vol 5 (3) ◽  
pp. 66
Author(s):  
Patrick Fasching ◽  
Stefan Rinnerhofer ◽  
Georg Wultsch ◽  
Philipp Birnbaumer ◽  
Peter Hofmann
Keyword(s):  
Power Output ◽  
Lactate Threshold ◽  
Maximal Oxygen Consumption ◽  
Cycle Ergometer ◽  
Physical Work ◽  
Maximal Power Output ◽  
Male And Female ◽  
Female Workers ◽  
Cycle Ergometer Test ◽  
Occupational Work

Long-term heavy physical work often leads to early retirement and disability pension due to chronic overload, with a need to define upper limits. The aim of this study was to evaluate the value of the first lactate threshold (LTP1) as a physiological marker for heavy occupational work. A total of 188 male and 52 female workers performed an incremental cycle ergometer test to determine maximal exercise performance and the first and second lactate (LTP1; LTP2) and ventilatory thresholds (VT1; VT2). Heart rate (HR) recordings were obtained during one eight-hour shift (HR8h) and oxygen uptake was measured during 20 minutes of a representative work phase. Energy expenditure (EE) was calculated from gas-exchange measures. Maximal power output (Pmax), maximal oxygen consumption (VO2 max) and power output at LTP1 and LTP2 were significantly different between male and female workers. HR8h was not significantly different between male and female workers. A significant relationship was found between Pmax and power output at LTP1. HR8h as a percentage of maximum HR significantly declined with increasing performance (Pmax:r = −0.56; p < 0.01; PLTP1:r = −0.49; p < 0.01). Despite different cardio-respiratory fitness-levels; 95.4% of all workers performed their usual work below LTP1. It is therefore suggested that LTP1 represents the upper limit for sustained heavy occupational work; which supports its use to determine work capability and assessing the limits of heavy occupational work.

Design and Evaluation of a Modified Underwater Cycle Ergometer

1996 ◽  
Vol 21 (2) ◽  
pp. 134-148 ◽  
Author(s):  
An A. Chen ◽  
Glen P. Kenny ◽  
Chad E. Johnston ◽  
Gordon G. Giesbrecht
Keyword(s):  
Power Output ◽  
Maximal Exercise ◽  
Exercise Duration ◽  
Cycle Ergometer ◽  
Gear Ratio ◽  
Upright Position ◽  
Exercise Tests ◽  
Maximal Power Output ◽  
Power Outputs ◽  
Key Words Core Temperature

An underwater cycle ergometer was designed consisting of an aluminum cycle frame in water connected with a 1:1 gear ratio to a mechanically braked standard cycle ergometer supported above the water. Three progressive maximal exercise tests were performed (n = 10): (a) the underwater ergometer in water (UEW), (b) underwater ergometer in air (UEA), and (c) a standard cycle ergometer in air (SEA). At submaximal power outputs, oxygen consumption [Formula: see text] and heart rate (HR) were generally lower in the SEA condition (p <.05), indicating that exercise in the upright position was more efficient. Exercise in water (UEW) resulted in lower total exercise duration, maximal HR, and maximal Tes than in air conditions. The upright position (SEA) resulted in greater total exercise duration and maximal power output than the semirecumbent positions. Because of positional differences between the standard and underwater ergometers, air-water comparisons should be made by using the underwater ergometer in water and on land. Key words: core temperature, esophageal temperature, skin temperature, exercise, resistance, work, power output, heat balance, heat loss, heat production, thermoregulation

The Cycling Physiology of Miguel Indurain 14 Years After Retirement

2012 ◽  
Vol 7 (4) ◽  
pp. 397-400 ◽  
Author(s):  
Iñigo Mujika
Keyword(s):  
Oxygen Uptake ◽  
Blood Lactate ◽  
Body Mass ◽  
Power Output ◽  
Aerobic Power ◽  
Cycle Ergometer ◽  
Cycle Ergometer Test ◽  
Age Related ◽  
The Individual ◽  
Aerobic Power Output

Age-related fitness declines in athletes can be due to both aging and detraining. Very little is known about the physiological and performance decline of professional cyclists after retirement from competition. To gain some insight into the aging and detraining process of elite cyclists, 5-time Tour de France winner and Olympic Champion Miguel Indurain performed a progressive cycle-ergometer test to exhaustion 14 y after retirement from professional cycling (age 46 y, body mass 92.2 kg). His maximal values were oxygen uptake 5.29 L/min (57.4 mL · kg−1 · min−1), aerobic power output 450 W (4.88 W/kg), heart rate 191 beats/min, blood lactate 11.2 mM. Values at the individual lactate threshold (ILT): 4.28 L/min (46.4 mL · kg−1 · min−1), 329 W (3.57 W/kg), 159 beats/min, 2.4 mM. Values at the 4-mM onset of blood lactate accumulation (OBLA): 4.68 L/min (50.8 mL · kg−1 · min−1), 369 W (4.00 W/kg), 170 beats/min. Average cycling gross efficiency between 100 and 350 W was 20.1%, with a peak value of 22.3% at 350 W. Delta efficiency was 27.04%. Absolute maximal oxygen uptake and aerobic power output declined by 12.4% and 15.2% per decade, whereas power output at ILT and OBLA declined by 19.8% and 19.2%. Larger declines in maximal and submaximal values relative to body mass (19.4–26.1%) indicate that body composition changed more than aerobic characteristics. Nevertheless, Indurain’s absolute maximal and submaximal oxygen uptake and power output still compare favorably with those exhibited by active professional cyclists.

The Na+-K+-ATPase α2 gene and trainability of cardiorespiratory endurance: the HERITAGE Family Study

2000 ◽  
Vol 88 (1) ◽  
pp. 346-351 ◽  
Author(s):  
Tuomo Rankinen ◽  
Louis Pérusse ◽  
Ingrid Borecki ◽  
Yvon C. Chagnon ◽  
Jacques Gagnon ◽  
...  
Keyword(s):  
Maximal Oxygen Consumption ◽  
Endurance Performance ◽  
Cycle Ergometer ◽  
Electrolyte Balance ◽  
Exercise Tests ◽  
Maximal Power Output ◽  
Length Polymorphisms ◽  
Ergometer Exercise ◽  
Exon 1 ◽  
N 93

The Na+-K+-ATPase plays an important role in the maintenance of electrolyte balance in the working muscle and thus may contribute to endurance performance. This study aimed to investigate the associations between genetic variants at the Na+-K+-ATPase α2 locus and the response (Δ) of maximal oxygen consumption (V˙o 2 max) and maximal power output (W˙max) to 20 wk of endurance training in 472 sedentary Caucasian subjects from 99 families. V˙o 2 max andW˙max were measured during two maximal cycle ergometer exercise tests before and again after the training program, and restriction fragment length polymorphisms at the Na+-K+-ATPase α2 (exons 1 and 21–22 with Bgl II) gene were typed. Sibling-pair linkage analysis revealed marginal evidence for linkage between the α2 haplotype and ΔV˙o 2 max ( P= 0.054) and stronger linkages between the α2 exon 21–22 marker ( P = 0.005) and α2 haplotype ( P = 0.003) and ΔW˙max. In the whole cohort, ΔV˙o 2 max in the 3.3-kb homozygotes of the exon 1 marker ( n = 5) was 41% lower than in the 8.0/3.3-kb heterozygotes ( n = 87) and 48% lower than in the 8.0-kb homozygotes ( n = 380; P = 0.018, adjusted for age, gender, baselineV˙o 2 max, and body weight). Among offspring, 10.5/10.5-kb homozygotes ( n = 14) of the exon 21–22 marker showed a 571 ± 56 (SE) ml O2/min increase inV˙o 2 max, whereas the increases in the 10.5/4.3-kb ( n = 93) and 4.3/4.3-kb ( n= 187) genotypes were 442 ± 22 and 410 ± 15 ml O2/min, respectively ( P = 0.017). These data suggest that genetic variation at the Na+-K+-ATPase α2 locus influences the trainability ofV˙o 2 max in sedentary Caucasian subjects.

scholarly journals Comparison of the talk test and percent heart rate reserve for exercise prescription

Kinesiology ◽  
2018 ◽  
Vol 50 (1) ◽  
pp. 3-10 ◽  
Author(s):  
John P. Porcari ◽  
Katelyn Falck-Wiese
Keyword(s):  
Exercise Intensity ◽  
Power Output ◽  
Repeated Measures ◽  
Exercise Prescription ◽  
Ventilatory Threshold ◽  
Body Height ◽  
Cycle Ergometer ◽  
Peak Power Output ◽  
Group Exercise ◽  
Cycle Ergometer Test

Exercise intensity is traditionally prescribed using %HRmax, %HRR, %VO2max, or %VO2R. Recently, the Talk Test (TT) has been proposed as an alternative method to guide exercise intensity. However, it is unknown if prescribing exercise intensity solely using the TT can provoke training responses that are comparable to traditional guidelines. This study compared the responses to training using either the TT or %HRR. Forty-four subjects (17 males and 27 females: age=20.4±3.02 years; body height=170.5±9.79 cm; body weight=71.9±13.63 kg) completed an incremental maximal cycle ergometer test, were stratified by VO2max and gender, and randomly assigned to training groups guided by either %HRR (n=20) or the TT (n=24). Both groups completed 40-minute training sessions three days per week for 10 weeks. In the HRR group, exercise intensity was targeted (per ACSM guidelines) at 40-59% HRR for weeks 1-4, 50-59% HRR for weeks 5-8, and 60-79% HRR for weeks 9-10. In the TT group, exercise intensity was targeted at the highest power output (PO) that still allowed for comfortable speech. Changes in VO2max, peak power output (PPO), VO2 at ventilatory threshold (VT), and PO at VT were compared between the groups using two-way ANOVA with repeated measures. There were significant (p&lt;.05) pre vs. post increases in VO2max (TT=10.6%; HRR=11.5%), PPO (TT=19%; HR=14%), VO2 at VT (T=32.7%; HRR=56.9%), and PO at VT (TT=43.1%; HRR=38.6%) in both groups, with no significant (p&gt;0.05) interaction effect. Guiding exercise prescription using the TT is a simple and effective method for prescribing exercise intensity and elicits improvements in exercise performance that are comparable to the traditional %HRR guidelines.

scholarly journals The influence of bicycle lean on maximal power output during sprint cycling

2021 ◽  
Author(s):  
Ross D. Wilkinson ◽  
Rodger Kram
Keyword(s):  
Power Output ◽  
Direct Evidence ◽  
Cycle Ergometer ◽  
Maximal Power ◽  
Maximal Power Output ◽  
Bicycle Dynamics ◽  
Competitive Cyclists ◽  
Sprint Cycling ◽  
Ad Libitum

Competitive cyclists typically sprint out of the saddle and alternately lean their bikes from side-to-side, away from the downstroke pedal. Yet, there is no direct evidence as to whether leaning the bicycle, or conversely, attempting to minimize lean, affects maximal power output during sprint cycling. Here, we modified a cycling ergometer so that it can lean from side-to-side but can also be locked to prevent lean. This modified ergometer made it possible to compare maximal 1-s crank power during non-seated, sprint cycling under three different conditions: locked (no lean), ad libitum lean, and minimal lean. We found that leaning the ergometer ad libitum did not enhance maximal 1-s crank power compared to a locked condition. However, trying to minimize ergometer lean decreased maximal 1-s crank power by an average of 5% compared to leaning ad libitum. IMU-derived measures of ergometer lean provided evidence that, on average, during the ad-lib condition, subjects leaned the ergometer away from the downstroke pedal as in overground cycling. This suggests that our ergometer provides a suitable emulation of lateral bicycle dynamics. Overall, we find that leaning a cycle ergometer ad libitum does not enhance maximal power output, and conversely, trying to minimize lean impairs maximal power output.

Predicting Cycling Performance in Trained to Elite Male and Female Cyclists

2014 ◽  
Vol 9 (4) ◽  
pp. 610-614 ◽  
Author(s):  
Robert P. Lamberts
Keyword(s):  
Power Output ◽  
High Performance ◽  
Perceived Exertion ◽  
Maximal Oxygen Consumption ◽  
Average Power ◽  
Time Trial ◽  
Cycling Performance ◽  
Gas Analysis ◽  
Peak Power Output ◽  
Male And Female

In high-performance cycling, it is important to maintain a healthy balance between training load and recovery. Recently a new submaximal cycle test, known as the Lamberts and Lambert Submaximal Cycle Test (LSCT), has been shown to be able to accurately predict cycling performance in 15 well-trained cyclists. The aim of this study was to determine the predictive value of the LSCT in 102 trained to elite cyclists (82 men and 20 women). All cyclists performed an LSCT test followed by a peak-power-output (PPO) test, which included respiratory-gas analysis for the determination of maximal oxygen consumption (VO2max). They then performed the LSCT test followed by a 40-km time trial (TT) 72 h later. Average power output during the 3 stages of the LSCT increased from 31%, 60%, and 79% of PPO, while the ratings of perceived exertion increased from 8 to 13 to 16. Very good relationships were found between actual and LSCT-predicted PPO (r = .98, 95%CI: .97–.98, P < .0001), VO2max (r = .96, 95%CI: .97–.99, P < .0001) and 40-km-TT time (r = .98, 95%CI: .94–.97, P < .0001). No gender differences were found when predicting cycling performance from the LSCT (P = .95). The findings of this study show that the LSCT is able to accurately predict cycling performance in trained to elite male and female cyclists and potentially can be used to prescribe and fine-tune training prescription in cycling.

Time to exhaustion during cycling is not well predicted by critical power calculations

2020 ◽  
Vol 45 (7) ◽  
pp. 753-760 ◽  
Author(s):  
Jesus G. Pallarés ◽  
Jose R. Lillo-Bevia ◽  
Ricardo Morán-Navarro ◽  
Victor Cerezuela-Espejo ◽  
Ricardo Mora-Rodriguez
Keyword(s):  
Oxygen Consumption ◽  
Power Output ◽  
Critical Power ◽  
Maximal Oxygen Consumption ◽  
Cycle Ergometer ◽  
Time To Exhaustion ◽  
Wingate Anaerobic Test ◽  
Wide Range ◽  
Power Outputs ◽  
Anaerobic Test

Three to 5 cycling tests to exhaustion allow prediction of time to exhaustion (TTE) at power output based on calculation of critical power (CP). We aimed to determine the accuracy of CP predictions of TTE at power outputs habitually endured by cyclists. Fourteen endurance-trained male cyclists underwent 4 randomized cycle-ergometer TTE tests at power outputs eliciting (i) mean Wingate anaerobic test (WAnTmean), (ii) maximal oxygen consumption, (iii) respiratory compensation threshold (VT2), and (iv) maximal lactate steady state (MLSS). Tests were conducted in duplicate with coefficient of variation of 5%–9%. Power outputs were 710 ± 63 W for WAnTmean, 366 ± 26 W for maximal oxygen consumption, 302 ± 31 W for VT2 and 247 ± 20 W for MLSS. Corresponding TTE were 00:29 ± 00:06, 03:23 ± 00:45, 11:29 ± 05:07, and 76:05 ± 13:53 min:s, respectively. Power output associated with CP was only 2% lower than MLSS (242 ± 19 vs. 247 ± 20 W; P < 0.001). The CP predictions overestimated TTE at WAnTmean (00:24 ± 00:10 mm:ss) and MLSS (04:41 ± 11:47 min:s), underestimated TTE at VT2 (–04:18 ± 03:20 mm:ss; P < 0.05), and correctly predicted TTE at maximal oxygen consumption. In summary, CP accurately predicts MLSS power output and TTE at maximal oxygen consumption. However, it should not be used to estimate time to exhaustion in trained cyclists at higher or lower power outputs (e.g., sprints and 40-km time trials). Novelty CP calculation enables to predict TTE at any cycling power output. We tested those predictions against measured TTE in a wide range of cycling power outputs. CP appropriately predicted TTE at maximal oxygen consumption intensity but err at higher and lower cycling power outputs.

Peak Oxygen Uptake in Children: Evaluation of an Older Prediction Method and Development of a New One

2008 ◽  
Vol 20 (1) ◽  
pp. 62-73 ◽  
Author(s):  
Sigurbjörn Árni Arngrímsson ◽  
Torarinn Sveinsson ◽  
Erlingur Jóhannsson
Keyword(s):  
Oxygen Uptake ◽  
Prediction Method ◽  
Resting Energy Expenditure ◽  
Prediction Equation ◽  
Peak Oxygen Uptake ◽  
Cycle Ergometer ◽  
Maximal Heart Rate ◽  
Maximal Power Output ◽  
Cycle Ergometer Test ◽  
New Equation

The purpose of this study was to validate an equation that has been used to predict peak oxygen uptake (VO2peak) and, if invalid, to develop a new equation predicting VO2peak from performance on a cycle ergometer test. Forty-five 9- and 15-year-old children underwent a VO2peak test and were randomized into developmental (DEV) and cross-validation (C-V) groups. The equation under validation, which requires knowledge of resting energy expenditure (REE), underestimated VO2peak (p < .05), but once adjusted with a new parameter calculated in DEV, it cross-validated well (rYY′ = .98, SE = .18 L · min−1). The accuracy of a new prediction equation built in DEV, not using REE, was confirmed in C-V (rYY′ = .98, SE = .17 L · min−1) and the slope and intercept were not different from the line of identity (p < .05). VO2peak in schoolchildren can be predicted with good accuracy from an equation based on the whole sample [VO2peak′ = −1.5986 + 0.0115 · (maximal power output) + 0.0109 · (mass) + 0.1313 · (gender) + 0.0085 · (maximal heart rate)].

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