scholarly journals Effect of sub-technique transitions on energy expenditure and physiological load in the classical-style technique among elite male cross-country skiers

2021 ◽  
Vol 121 (11) ◽  
pp. 3201-3209
Author(s):  
Tomas Carlsson ◽  
Lars Wedholm ◽  
Wilma Fjordell ◽  
Mikael Swarén ◽  
Magnus Carlsson
Keyword(s):  
Energy Expenditure ◽  
Lactate Concentration ◽  
Metabolic Stress ◽  
Blood Lactate Concentration ◽  
Energy Contribution ◽  
Mean Values ◽  
Paired Samples ◽  
Cross Country ◽  
Classical Style ◽  
Continuous Use

Abstract Purpose To investigate whether sub-technique transitions in the classical-style technique are associated with increased energy expenditure and/or metabolic stress among elite male cross-country skiers. Methods Fifteen elite male skiers completed three 10-min treadmill roller-skiing tests, each of which consisted of 5 min using the diagonal-stride technique (DS) and 5 min using the double-poling technique (DP), combined in three various modes all ensuring comparable mechanical workload, at an inclination of 2.5° and a speed of 13 km/h. In the first and third tests, the participants used 5 min continuous DS followed by 5 min continuous DP, or vice versa (no transition (NT) test), whereas in the second test, they made transitions between DS and DP every 6 s (repeated transition (RT) test). The last 3 min of each 5-min stage was used to calculate the mean values of oxygen uptake ($${\dot{\text{V}}\text{O}}_{{2}}$$ V ˙ O 2 ), respiratory exchange ratio (RER), metabolic rate (MR), mechanical work rate (MWR), and gross efficiency (GE). In addition, the pre–post-difference in blood lactate concentration (Ladiff) was determined for each test. Paired-samples t tests were used to investigate differences between tests. Results There were no significant differences between NT and RT tests regarding V̇O2, MR, MWR, or GE. Conversely, significant differences were found in RER and Ladiff, where the NT test was associated with higher RER and Ladiff values. Conclusions Roller skiing with repeated sub-technique transitions is not associated with an additional aerobic energy contribution; instead, the anaerobic energy contribution was lower compared to that under continuous use of DS and DP.

scholarly journals Physiological responses and cycle characteristics during double-poling versus diagonal-stride roller-skiing in junior cross-country skiers

2021 ◽  
Author(s):  
Erik P. Andersson ◽  
Irina Hämberg ◽  
Paulo Cesar Do Nascimento Salvador ◽  
Kerry McGawley
Keyword(s):  
Oxygen Uptake ◽  
Perceived Exertion ◽  
Lactate Concentration ◽  
Blood Lactate Concentration ◽  
Peak Oxygen Uptake ◽  
Submaximal Exercise ◽  
Rating Of Perceived Exertion ◽  
Time To Exhaustion ◽  
Double Poling ◽  
Cross Country

Abstract Purpose This study aimed to compare physiological factors and cycle characteristics during cross-country (XC) roller-skiing at matched inclines and speeds using the double-poling (DP) and diagonal-stride (DS) sub-techniques in junior female and male XC skiers. Methods Twenty-three well-trained junior XC skiers (11 women, 12 men; age 18.2 ± 1.2 yr.) completed two treadmill roller-skiing tests in a randomized order using either DP or DS. The exercise protocols were identical and included a 5 min warm-up, 4 × 5 min submaximal stages, and an incremental test to exhaustion, all performed at a 5° incline. Results No significant three-way interactions were observed between sex, submaximal exercise intensity, and sub-technique. For the pooled sample, higher values were observed for DP versus DS during submaximal exercise for the mean oxygen uptake kinetics response time (33%), energy cost (18%), heart rate (HR) (9%), blood lactate concentration (5.1 versus 2.1 mmol·L−1), rating of perceived exertion (12%), and cycle rate (25%), while cycle length was lower (19%) (all P < 0.001). During the time-to-exhaustion (TTE) test, peak oxygen uptake ($$\dot{V}$$ V ˙ O2peak), peak HR, and peak oxygen pulse were 8%, 2%, and 6% lower, respectively, for DP than DS, with a 29% shorter TTE during DP (pooled data, all P < 0.001). Conclusion In well-trained junior XC skiers, DP was found to exert a greater physiological load than DS during uphill XC roller-skiing at submaximal intensities. During the TTE test, both female and male athletes were able to ski for longer and reached markedly higher $$\dot{V}$$ V ˙ O2peak values when using DS compared to DP.

Strength, Power, and Aerobic Exercise Correlates of 5-km Cross-Country Running Performance in Adolescent Runners

2006 ◽  
Vol 18 (3) ◽  
pp. 374-384 ◽  
Author(s):  
Andrew S. Cole ◽  
Megan E. Woodruff ◽  
Mary P. Horn ◽  
Anthony D. Mahon
Keyword(s):  
Muscle Power ◽  
Pearson Correlation ◽  
Vertical Jump ◽  
Lactate Concentration ◽  
Blood Lactate Concentration ◽  
Correlation Coefficients ◽  
Knee Extension ◽  
Running Economy ◽  
Running Performance ◽  
Cross Country

Relationships between physiological parameters and 5-km running performance were examined in 15 male runners (17.3 ± 0.9 years). Running economy (RE) and blood lactate concentration ([BLa]) at 241.2 m/min, VO2max, velocity at VO2max (vVO2max), vertical jump height and muscle power, and isokinetic knee extension strength at 60°/sec and 240°/sec were measured. The participants’ best 5-km race time over the last month of the cross-country season (16.98 ± 0.76 min) was used in the analysis. The data were analyzed using Pearson correlation coefficients. Significant relationships to run time were observed for VO2max (r = -.53), RE (r = .55), and vVO2max (r = -.66), but not [BLa], isokinetic muscle torque, or vertical jump. Identifying the unique strength and power characteristics related to running performance in this age group is warranted.

Acute anemia increases lactate production and decreases clearance during exercise

1989 ◽  
Vol 67 (2) ◽  
pp. 756-764 ◽  
Author(s):  
S. G. Gregg ◽  
R. S. Mazzeo ◽  
T. F. Budinger ◽  
G. A. Brooks
Keyword(s):  
Blood Glucose ◽  
Blood Lactate ◽  
Lactate Concentration ◽  
Lactate Production ◽  
Blood Lactate Concentration ◽  
Flow Distribution ◽  
Plasma Catecholamine ◽  
Metabolic Clearance ◽  
Sprague Dawley ◽  
Mean Values

We evaluated whether elevated blood lactate concentration during exercise in anemia is the result of elevated production or reduced clearance. Female Sprague-Dawley rats were made acutely anemic by exchange transfusion of plasma for whole blood. Hemoglobin and hematocrit were reduced 33%, to 8.6 +/- 0.4 mg/dl and 26.5 +/- 1.1%, respectively. Blood lactate kinetics were studied by primed continuous infusion of [U-14C]lactate. Blood flow distribution during rest and exercise was determined from injection of 153Gd- and 113Sn-labeled microspheres. Resting blood glucose (5.1 +/- 0.2 mM) and lactate (1.9 +/- 0.02 mM) concentrations were not different in anemic animals. However, during exercise blood glucose was lower in anemic animals (4.0 +/- 0.2 vs. 4.6 +/- 0.1 mM) and lactate was higher (6.1 +/- 0.4 vs. 2.3 +/- 0.5 mM). Blood lactate disposal rates (turnover measured with recyclable tracer, Ri) were not different at rest and averaged 136 +/- 5.8 mumol.kg-1.min-1. Ri was significantly elevated in both control (260.9 +/- 7.1 mumol.kg-1.min-1) and anemic animals (372.6 +/- 8.6) during exercise. Metabolic clearance rate (MCR = Ri/[lactate]) did not differ during rest (151 +/- 8.2 ml.kg-1.min-1); MCR was reduced more by exercise in anemic animals (64.3 +/- 3.8) than in controls (129.2 +/- 4.1). Plasma catecholamine levels were not different in resting rats, with pooled mean values of 0.45 +/- 0.1 and 0.48 +/- 0.1 ng/ml for epinephrine (E) and norepinephrine (NE), respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

scholarly journals Does caffeine supplementation alter energy contribution during a work-based ~30 min cycling time-trial?

2020 ◽  
Vol 34 (3) ◽  
pp. 471-481
Author(s):  
Gabriel Barreto ◽  
Rafael Pires da Silva ◽  
Guilherme Yamaguchi ◽  
Luana Farias de Oliveira ◽  
Vitor de Salles Painelli ◽  
...  
Keyword(s):  
Perceived Exertion ◽  
Lactate Concentration ◽  
Blood Lactate Concentration ◽  
Time Trial ◽  
Energy System ◽  
Energy Contribution ◽  
Mean Power ◽  
Double Blind ◽  
Cycling Time Trial ◽  
Cycling Time

Caffeine has been shown to increase anaerobic energy contribution during short-duration cycling time-trials (TT) though no information exists on whether caffeine alters energy contribution during more prolonged, aerobic type TTs. The aim of this study was to determine the effects of caffeine supplementation on longer and predominantly aerobic exercise. Fifteen recreationally-trained male cyclists (age 38±8 y, height 1.76±0.07 m, body mass 72.9±7.7 kg) performed a ~30 min cycling TT following either 6 mg·kg-1BM caffeine (CAF) or placebo (PLA) supplementation, and one control (CON) session without supplementation, in a double- -blind, randomised, counterbalance and cross-over design. Mean power output (MPO) was recorded as the outcome measure. Respiratory values were measured throughout exercise for the determination of energy system contribution. Data were analysed using mixed-models. CAF improved mean MPO compared to CON (P=0.01), and a trend towards an improvement compared to PLA (P=0.07); there was no difference in MPO at any timepoint throughout the exercise between conditions. There was a main effect of Condition (P=0.04) and Time (P<0.0001) on blood lactate concentration, which tended to be higher in CAF vs. both PLA and CON (Condition effect, both P=0.07). Ratings of perceived exertion increased over time (P<0.0001), with no effect of Condition or interaction (both P>0.05). Glycolytic energy contribution was increased in CAF compared to CON and PLA (both P<0.05), but not aerobic or ATP-CP (both P>0.05). CAF improved aerobic TT performance compared to CON, which could be explained by increased glycolytic energy contribution.

scholarly journals Repeated Bouts of Advanced Strength Training Techniques: Effects on Volume Load, Metabolic Responses, and Muscle Activation in Trained Individuals

Sports ◽  
2019 ◽  
Vol 7 (1) ◽  
pp. 14 ◽  
Author(s):  
William Wallace ◽  
Carlos Ugrinowitsch ◽  
Matt Stefan ◽  
Jacob Rauch ◽  
Christopher Barakat ◽  
...  
Keyword(s):  
Strength Training ◽  
Muscle Activation ◽  
Perceived Exertion ◽  
Training Stimulus ◽  
Lactate Concentration ◽  
Training Session ◽  
Metabolic Stress ◽  
Blood Lactate Concentration ◽  
Training Techniques ◽  
Volume Load

This study investigated the effects of advanced training techniques (ATT) on muscular responses and if performing a second training session would negatively affect the training stimulus. Eleven strength-trained males performed a traditional strength training session (TST) and four different ATT: pre-exhaustion A (PE-A), pre-exhaustion B (PE-B), forced repetitions (FR), and super-set (SS). On day 1, SS produced lower volume load than TST, FR, and PE-B (−16.0%, p ≤ 0.03; −14.9, p ≤ 0.03 and −18.2%, p ≤ 0.01, respectively). On day 2, SS produced lower volumes than all the other ATT (−9.73–−18.5%, p ≤ 0.03). Additionally, subjects demonstrated lower perceived exertion on day 1 compared to day 2 (6.5 ± 0.4 AU vs. 8.7 ± 0.3 AU, p = 0.0001). For blood lactate concentration [La-] on days 1 and 2, [La-] after the tenth set was the highest compared to all other time points (baseline: 1.7 ± 0.2, fifth-set: 8.7 ± 1.0, tenth-set 9.7 ± 0.9, post-5 min: 8.7 ± 0.7 mmol∙L−1, p ≤ 0.0001). Acute muscle swelling was greater immediately and 30-min post compared to baseline (p ≤ 0.0001). On day 2, electromyography (EMG) amplitude on the clavicular head of the pectoralis major was lower for SS than TST, PE-A, and PE-B (−11.7%, p ≤ 0.01; −14.4%, p ≤ 0.009; −20.9%, p = 0.0003, respectively). Detrimental effects to the training stimulus were not observed when ATT (besides SS) are repeated. Strength trained individuals can sustain performance, compared to TST, when they are using ATT in an acute fashion. Although ATT have traditionally been used as a means to optimize metabolic stress, volume load, and neuromuscular responses, our data did not project differences in these variables compared to TST. However, it is important to note that different ATT might produce slight changes in volume load, muscle excitation, and fluid accumulation in strength-trained individuals from session to session.

scholarly journals Validating Physiological and Biomechanical Parameters during Continuous Swimming at Speed Corresponding to Lactate Threshold

Proceedings ◽  
2019 ◽  
Vol 25 (1) ◽  
pp. 4
Author(s):  
Gavriil G. Arsoniadis ◽  
Ioannis S. Nikitakis ◽  
Petros G. Botonis ◽  
Ioannis Malliaros ◽  
Argyris G. Toubekis
Keyword(s):  
Lactate Threshold ◽  
Lactate Concentration ◽  
Blood Lactate Concentration ◽  
Maximum Speed ◽  
Front Crawl ◽  
Stroke Length ◽  
Mean Values ◽  
Speed Test ◽  
Biomechanical Parameters ◽  
The Individual

AIM: The purpose of this study was to validate the physiological responses and biomechanical parameters during continuous swimming at intensity corresponding to lactate threshold previously calculated by an intermittent, progressively increasing speed test (7 × 200-m). MATERIAL & METHOD: Nine competitive male and female swimmers (age, 19.2 ± 2.3 years; height, 175.3 ± 7.5 cm; body mass, 67.6 ± 8.7 kg; VO2max, 46.5 ± 15.6 mL/kg/min) performed a 7 × 200-m front crawl test reaching maximum speed in the last effort. Blood lactate concentration (BL) and oxygen uptake (VO2) were determined after each repetition, while heart rate (HR) was recorded continuously. Stroke rate (SR) and stroke length (SL) were measured in each 200-m effort. The speed at lactate threshold (sLT) was calculated using the individual speed vs. BL, and subsequently BL, VO2, HR, SR, and SL corresponding to sLT were calculated (BL-sLT, VO2-sLT, HR-sLT, SR-sLT, and SL-sLT). On a subsequent day, swimmers performed 30-min continuous swimming (T30) with a constant speed corresponding to sLT. BL, V02, HR, SR, and SL (BL-T30, V02-T30, HR-T30, SR-T30, and SL-T30) were measured in the 10th and 30th minutes of the T30 test, and the mean values were used for the statistical analysis. RESULTS: The speed corresponding to sLT was not different from the speed at T30 (1.33 ± 0.08 vs. 1.32 ± 0.09 m/s, p > 0.05). There was no difference between tests in VO2 (VO2-sLT, 34.9 ± 13.3 vs. VO2-T30, 32.1 ± 11.4 ml/kg/min, p = 0.47). However, not all swimmers were able to complete T30 at sLT, and BL, HR, and SR were higher, while SL was lower at the end of T30 compared to sLT (BL-sLT, 3.47 ± 0.60 mmol/L vs. BL-T30, 5.28 ± 3.15 mmol/L, p = 0.05; HR-sLT, 163 ± 10 vs. HR-T30, 171 ± 11 b/min, p = 0.03; SR-sLT, 28.0 ± 4.0 vs. SR-T30, 33.8 ± 3.2 strokes/min, p < 0.001; SL-sLT, 2.6 ± 0.4 vs. SL-T30, 2.4 ± 0.3 m/cycles, p < 0.001). A Bland-and-Altman plot indicated agreement between 7 × 200 and T30 in BL (bias 1.8 ± 2.4 mmol/L), VO2 (bias −2.9 ± 11.4 ml/kg/min), HR (bias 10.3 ± 12 b/min), SR (bias 5.3 ± 3.4 strokes/min), and SL (bias −0.3 ± 0.2 m/cycle), but the range of physiological and biomechanical data variations was large. CONCLUSIONS: Continuous swimming at speed corresponding to lactate threshold may not show the same physiological and biomechanical responses as those predicted by a progressively increasing speed test of 7 × 200-m.

Does Prior 1500-m Swimming Affect Cycling Energy Expenditure in Well-Trained Triathletes?

2005 ◽  
Vol 30 (4) ◽  
pp. 392-403 ◽  
Author(s):  
Anne Delextrat ◽  
Jeanick Brisswalter ◽  
Christophe Hausswirth ◽  
Thierry Bernard ◽  
Jean-Marc Vallier
Keyword(s):  
Energy Expenditure ◽  
Blood Lactate ◽  
Energy Demand ◽  
Lactate Concentration ◽  
Blood Lactate Concentration ◽  
Exercise Duration ◽  
Cycle Ergometer ◽  
Warm Up ◽  
Key Words Lactate ◽  
Pedaling Frequency

The purpose of this study was to determine the effects of a 1,500-m swim on energy expenditure during a subsequent cycle task. Eight well-trained male triathletes (age 26.0 ± 5.0 yrs; height 179.6 ± 4.5 cm; mass 71.3 ± 5.8 kg; [Formula: see text] 71.9 ± 7.8 ml kg−1•min−1) underwent two testing sessions in counterbalanced order. The sessions consisted of a 30-min ride on the cycle ergometer at 75% of maximal aerobic power (MAP), and at a pedaling frequency of 95 rev•min−1, preceded either by a 1,500-m swim at 1.20 m•s−1 (SC trial) or by a cycling warm-up at 30% of MAP (C trial). Respiratory and metabolic data were collected between the 3rd and the 5th min, and between the 28th and 30th min of cycling. The main results indicated a significantly lower gross efficiency (13.0%) and significantly higher blood lactate concentration (56.4%), [Formula: see text] (5.0%), HR (9.3%), [Formula: see text] (15.7%), and RF (19.9%) in the SC compared to the C trial after 5 min, p <  0.05. After 30 min, only [Formula: see text] (7.9%) and blood lactate concentration (43.9%) were significantly higher in the SC compared to the C trial, p <  0.05. These results confirm the increase in energy cost previously observed during sprint-distance triathlons and point to the importance of the relative intensity of swimming on energy demand during subsequent cycling. Key words: lactate, oxygen uptake, intensity, exercise duration, performance

scholarly journals Performance Diagnostic in Cross-Country Skiing

2015 ◽  
Vol 16 (2) ◽  
Author(s):  
Benedikt A. Gasser ◽  
Hans H. Hoppeler
Keyword(s):  
Heart Rate ◽  
Blood Lactate ◽  
Lactate Concentration ◽  
Blood Lactate Concentration ◽  
Endurance Capacity ◽  
Maximum Heart Rate ◽  
Running Speed ◽  
Cross Country Skiing ◽  
Cross Country ◽  
The Relationship

AbstractPurpose. Recreational cross-country skiers can benefit from a performance diagnostic when planning a training program. The aim of this study was to establish a simple test protocol to measure endurance capacity and provide training recommendations. Methods. The relationship between endurance performance and cross-country skiing technique was assessed using two tests. First, a lactate threshold test whereby running speed was determined on a treadmill at 4 mmol/l blood lactate concentration. Second, participants completed a variation of the Cooper test using skating technique on flat terrain to determine the distance covered in 12 min and maximum heart rate. Results. There was a correlative (r = 0.18 respectivelly R2 = 0.43) relationship of between the distance covered in the Cooper test and treadmill running speed at 4 mmol/l blood lactate concentration. Conclusions. The two tests allow recreational athletes to rank themselves with regards to their endurance capacity within a population. The relationship between distance covered and maximum heart rate can indicate whether future training should focus on technical or physical improvement.

scholarly journals Does caffeine supplementation alter energy contribution during a work-based ~30 min cycling time-trial?

2020 ◽  
Vol 34 (3) ◽  
pp. 471-481
Author(s):  
Gabriel Barreto ◽  
Rafael Pires da Silva ◽  
Guilherme Yamaguchi ◽  
Luana Farias de Oliveira ◽  
Vitor de Salles Painelli ◽  
...  
Keyword(s):  
Perceived Exertion ◽  
Lactate Concentration ◽  
Blood Lactate Concentration ◽  
Time Trial ◽  
Energy System ◽  
Energy Contribution ◽  
Mean Power ◽  
Double Blind ◽  
Cycling Time Trial ◽  
Cycling Time

Caffeine has been shown to increase anaerobic energy contribution during short-duration cycling time-trials (TT) though no information exists on whether caffeine alters energy contribution during more prolonged, aerobic type TTs. The aim of this study was to determine the effects of caffeine supplementation on longer and predominantly aerobic exercise. Fifteen recreationally-trained male cyclists (age 38±8 y, height 1.76±0.07 m, body mass 72.9±7.7 kg) performed a ~30 min cycling TT following either 6 mg·kg-1BM caffeine (CAF) or placebo (PLA) supplementation, and one control (CON) session without supplementation, in a double- -blind, randomised, counterbalance and cross-over design. Mean power output (MPO) was recorded as the outcome measure. Respiratory values were measured throughout exercise for the determination of energy system contribution. Data were analysed using mixed-models. CAF improved mean MPO compared to CON (P=0.01), and a trend towards an improvement compared to PLA (P=0.07); there was no difference in MPO at any timepoint throughout the exercise between conditions. There was a main effect of Condition (P=0.04) and Time (P<0.0001) on blood lactate concentration, which tended to be higher in CAF vs. both PLA and CON (Condition effect, both P=0.07). Ratings of perceived exertion increased over time (P<0.0001), with no effect of Condition or interaction (both P>0.05). Glycolytic energy contribution was increased in CAF compared to CON and PLA (both P<0.05), but not aerobic or ATP-CP (both P>0.05). CAF improved aerobic TT performance compared to CON, which could be explained by increased glycolytic energy contribution.

Increasing Oxygen Uptake in Well-Trained Cross-Country Skiers During Work Intervals With a Fast Start

2020 ◽  
Vol 15 (3) ◽  
pp. 383-389 ◽  
Author(s):  
Bent R. Rønnestad ◽  
Tue Rømer ◽  
Joar Hansen
Keyword(s):  
Peak Power ◽  
Perceived Exertion ◽  
Lactate Concentration ◽  
Blood Lactate Concentration ◽  
Constant Speed ◽  
Rating Of Perceived Exertion ◽  
Leg Press ◽  
Maximal Aerobic Speed ◽  
Fast Start ◽  
Cross Country

Purpose: Accumulated time at a high percentage of peak oxygen consumption (VO2peak) is important for improving performance in endurance athletes. The present study compared the acute effect of a roller-ski skating session containing work intervals with a fast start followed by decreasing speed (DEC) with a traditional session where the work intervals had a constant speed (similar to the mean speed of DEC; TRAD) on physiological responses, rating of perceived exertion, and leg press peak power. Methods: A total of 11 well-trained cross-country skiers performed DEC and TRAD in a randomized order (5 × 5-min work intervals, 3-min relief). Each 5-minute work interval in the DEC protocol started with 1.5 minutes at 100% of maximal aerobic speed followed by 3.5 minutes at 85% of maximal aerobic speed, whereas the TRAD protocol had a constant speed at 90% of maximal aerobic speed. Results: DEC induced a higher VO2 than TRAD, measured as both peak and average of all work intervals during the session (98.2% [2.1%] vs 95.4% [3.1%] VO2peak, respectively, and 87.6% [1.9%] vs 86.1% [3.2%] VO2peak, respectively) with a lower mean rating of perceived exertion after DEC than TRAD (16.1 [1.0] vs 16.5 [0.7], respectively) (all P < .05). There were no differences between sessions for mean heart rate, blood lactate concentration, or leg press peak power. Conclusion: DEC induced a higher mean VO2 and a lower rating of perceived exertion than TRAD, despite similar mean speed, indicating that DEC can be a good strategy for interval sessions aiming to accumulate more time at a high percentage of VO2peak.

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