Effects of supplementing with an 18% carbohydrate-hydrogel drink versus a placebo during whole-body exercise in −5 °C with elite cross-country ski athletes: a crossover study

Abstract Background Whilst the ergogenic effects of carbohydrate intake during prolonged exercise are well-documented, few investigations have studied the effects of carbohydrate ingestion during cross-country skiing, a mode of exercise that presents unique metabolic demands on athletes due to the combined use of large upper- and lower-body muscle masses. Moreover, no previous studies have investigated exogenous carbohydrate oxidation rates during cross-country skiing. The current study investigated the effects of a 13C-enriched 18% multiple-transportable carbohydrate solution (1:0.8 maltodextrin:fructose) with additional gelling polysaccharides (CHO-HG) on substrate utilization and gastrointestinal symptoms during prolonged cross-country skiing exercise in the cold, and subsequent double-poling time-trial performance in ~ 20 °C. Methods Twelve elite cross-country ski athletes (6 females, 6 males) performed 120-min of submaximal roller-skiing (69.3 ± 2.9% of $$ \dot{\mathrm{V}} $$V̇O2peak) in −5 °C while receiving either 2.2 g CHO-HG·min− 1 or a non-caloric placebo administered in a double-blind, randomized manner. Whole-body substrate utilization and exogenous carbohydrate oxidation was calculated for the last 60 min of the submaximal exercise. The maximal time-trial (2000 m for females, 2400 m for males) immediately followed the 120-min submaximal bout. Repeated-measures ANOVAs with univariate follow-ups were conducted, as well as independent and paired t-tests, and significance was set at P < 0.05. Data are presented as mean ± SD. Results Exogenous carbohydrate oxidation contributed 27.6 ± 6.6% to the total energy yield with CHO-HG and the peak exogenous carbohydrate oxidation rate reached 1.33 ± 0.27 g·min− 1. Compared to placebo, fat oxidation decreased by 9.5 ± 4.8% with CHO-HG, total carbohydrate oxidation increased by 9.5 ± 4.8% and endogenous carbohydrate utilization decreased by 18.1 ± 6.4% (all P < 0.05). No severe gastrointestinal symptoms were reported in either trial and euhydration was maintained in both trials. Time-trial performance (8.4 ± 0.4 min) was not improved following CHO-HG compared to placebo (− 0.8 ± 3.5 s; 95% confidence interval − 3.0 to 1.5 s; P = 0.46). No sex differences were identified in substrate utilization or relative performance. Conclusions Ingestion of an 18% multiple-transportable carbohydrate solution with gelling polysaccharides was found to be well-tolerated during 120 min of submaximal whole-body exercise, but did not improve subsequent maximal double-poling performance.

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Effects of creatine loading and prolonged creatine supplementation on body composition, fuel selection, sprint and endurance performance in humans

Clinical Science ◽

10.1042/cs1040153 ◽

2003 ◽

Vol 104 (2) ◽

pp. 153-162 ◽

Cited By ~ 10

Author(s):

Luc J.C. van LOON ◽

Audrey M. OOSTERLAAR ◽

Fred HARTGENS ◽

Matthijs K.C. HESSELINK ◽

Rodney J. SNOW ◽

...

Keyword(s):

Body Composition ◽

Creatine Supplementation ◽

Time Trial ◽

Oxidative Capacity ◽

Substrate Utilization ◽

Cycle Ergometer ◽

Fat Free Mass ◽

Whole Body ◽

Total Creatine ◽

Trial Performance

Most research on creatine has focused on short-term creatine loading and its effect on high-intensity performance capacity. Some studies have investigated the effect of prolonged creatine use during strength training. However, studies on the effects of prolonged creatine supplementation are lacking. In the present study, we have assessed the effects of both creatine loading and prolonged supplementation on muscle creatine content, body composition, muscle and whole-body oxidative capacity, substrate utilization during submaximal exercise, and on repeated supramaximal sprint, as well as endurance-type time-trial performance on a cycle ergometer. Twenty subjects ingested creatine or a placebo during a 5-day loading period (20g·day-1) after which supplementation was continued for up to 6 weeks (2g·day-1). Creatine loading increased muscle free creatine, creatine phosphate (CrP) and total creatine content (P<0.05). The subsequent use of a 2g·day-1 maintenance dose, as suggested by an American College of Sports Medicine Roundtable, resulted in a decline in both the elevated CrP and total creatine content and maintenance of the free creatine concentration. Both short- and long-term creatine supplementation improved performance during repeated supramaximal sprints on a cycle ergometer. However, whole-body and muscle oxidative capacity, substrate utilization and time-trial performance were not affected. The increase in body mass following creatine loading was maintained after 6 weeks of continued supplementation and accounted for by a corresponding increase in fat-free mass. This study provides definite evidence that prolonged creatine supplementation in humans does not increase muscle or whole-body oxidative capacity and, as such, does not influence substrate utilization or performance during endurance cycling exercise. In addition, our findings suggest that prolonged creatine ingestion induces an increase in fat-free mass.

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The Influence of Pole Length on Performance, O2 Cost, and Kinematics in Double Poling

International Journal of Sports Physiology and Performance ◽

10.1123/ijspp.2015-0754 ◽

2017 ◽

Vol 12 (2) ◽

pp. 211-217 ◽

Cited By ~ 13

Author(s):

Thomas Losnegard ◽

Håvard Myklebust ◽

Øyvind Skattebo ◽

Hans Kristian Stadheim ◽

Øyvind Sandbakk ◽

...

Keyword(s):

Center Of Mass ◽

Body Height ◽

Time Trial ◽

Test Protocol ◽

Warm Up ◽

Vertical Range ◽

Double Poling ◽

Cross Country Skiing ◽

Cross Country ◽

Identical Test

Purpose:In the double-poling (DP) cross-country-skiing technique, propulsive forces are transferred solely through the poles. The aim of the current study was to investigate how pole length influences DP performance, O2 cost, and kinematics during treadmill roller skiing.Methods:Nine male competitive cross-country skiers (24 ± 3 y, 180 ± 5 cm, 72 ± 5 kg, VO2max running 76 ± 6 mL · kg–1 · min–1) completed 2 identical test protocols using self-selected (84% ± 1% of body height) and long poles (self-selected + 7.5 cm; 88% ± 1% of body height) in a counterbalanced fashion. Each test protocol included a 5-min warm-up (2.5 m/s; 2.5°) and three 5-min submaximal sessions (3.0, 3.5, and 4.0 m/s; 2.5°) for assessment of O2 cost, followed by a selfpaced 1000-m time trial (~3 min, >5.0 m/s; 2.5°). Temporal patterns and kinematics were assessed using accelerometers and 2D video.Results:Long poles reduced 1000-m time (mean ± 90% confidence interval; –1.0% ± 0.7%, P = .054) and submaximal O2 cost (–2.7% ± 1.0%, P = .002) compared with self-selected poles. The center-of-mass (CoM) vertical range of displacement tended to be smaller for long than for self-selected poles (23.3 ± 3.0 vs 24.3 ± 3.0 cm, P = .07). Cycle and reposition time did not differ between pole lengths at any speeds tested, whereas poling time tended to be shorter for self-selected than for long poles at the lower speeds (≤3.5 m/s, P ≤ .10) but not at the higher speeds (≥4.0 m/s, P ≥ .23).Conclusions:DP 1000-m time, submaximal O2 cost, and CoM vertical range of displacement were reduced in competitive cross-country skiers using poles 7.5 cm longer than self-selected ones.

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No Effect of Pre-exercise Meal on Substrate Metabolism and Time Trial Performance during Intense Endurance Exercise

International Journal of Sport Nutrition and Exercise Metabolism ◽

10.1123/ijsnem.13.4.489 ◽

2003 ◽

Vol 13 (4) ◽

pp. 489-503 ◽

Cited By ~ 8

Author(s):

David Paul ◽

Kevin A. Jacobs ◽

Raymond J. Geor ◽

Kenneth W. Hinchcliff

Keyword(s):

Lactate Threshold ◽

Energy Content ◽

Time Trial ◽

Fat Oxidation ◽

Carbohydrate Oxidation ◽

Whole Body ◽

Macronutrient Composition ◽

Glycogen Utilization ◽

And Performance ◽

Trial Performance

To determine the effect of macronutrient composition of pre-exercise meals on exercise metabolism and performance, 8 trained men exercised for 30 min above lactate threshold (30LT), followed by a 20-km time trial (TT). Approximately 3.5 h before exercise, subjects consumed a carbohydrate meal (C; 3 g carbohydrate/kg), an isoenergetic fat meal (F; 1.3 g fat/kg), or a placebo meal (P; no energy content) on 3 separate occasions in randomized order. Treatments had no effect on carbohydrate oxidation during exercise, but C decreased whole-body fat oxidation during the last 5 min of 30LT and TT, respectively (3.2 ± 1.6 and 4.8 ± 2.1 mmol · kg−1 · min−1, p < .05) when compared to F (13.3 ± 1.6 and 16.5 ± 2.7 mmol · kg−1 · min−1) and P (15.9 ± 2.7 and 17.0 ± 3.2 mmol · kg−1 · min−1). Glucose rate of appearance (Ra) and disappearance (Rd), and muscle glycogen utilization were not significantly different among treatments during exercise. TT performances were similar for C, F, and P (32.7 ± 0.5 vs. 33.1 ± 1.1 and 33.0 ± 0.8 min, p > .05). We conclude that the consumption of a pre-exercise meal has minor effects on fat oxidation during high-intensity exercise, and no effect on carbohydrate oxidation or TT performance.

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Laboratory- and field-based performance-predictions in cross-country skiing and roller-skiing

PLoS ONE ◽

10.1371/journal.pone.0256662 ◽

2021 ◽

Vol 16 (8) ◽

pp. e0256662

Author(s):

Rune Kjøsen Talsnes ◽

Guro Strøm Solli ◽

Jan Kocbach ◽

Per-Øyvind Torvik ◽

Øyvind Sandbakk

Keyword(s):

National Level ◽

Time Trial ◽

Strongly Correlated ◽

Performance Indices ◽

Performance Predictions ◽

Double Poling ◽

Individual Distance ◽

Cross Country Skiing ◽

Cross Country ◽

And Performance

The purpose of the present study was to investigate how various laboratory- and field-based tests predict on-snow cross-country (XC) skiing and roller-skiing performance. Thirty-three national-level male XC skiers (19.0±2.5 years, maximal oxygen uptake [VO2max] 70.8±4.7 mL·min-1·kg-1) performed a 13.6-km roller-ski skating competition tracked by a global positioning system (GPS), which together with individual distance International Ski Federation (FIS) points was used to assess their performance level. On separate days, time in a 6.4-km uphill running time-trial (RUN-TT) and 1.3-km uphill roller-ski double-poling time-trial (DP-TT) was measured in the field and performance indices determined while running and roller-ski skating in the laboratory. The mean finishing times for the RUN-TT and the DP-TT showed moderate to large correlations with distance FIS points and performance in the roller-ski skating competition (r = 0.56–0.72; all p<0.05). RUN-TT was more strongly correlated with distance FIS points than DP-TT (r = 0.72 versus 0.56; p<0.05). Performance indices and VO2max in incremental running and roller-ski skating in the laboratory showed large to very large correlations with distance FIS points and roller-skiing performance (r = 0.50–0.90; all p<0.05). Performance indices and VO2max in running tended to be more strongly correlated with roller-skiing performance than corresponding values obtained while roller-ski skating (all p<0.10). The present findings suggest that both laboratory performance indices and field-based performance tests provide valid predictions of XC skiing and roller-skiing performance in a heterogeneous group of male XC skiers, with test values obtained in running tending to be more strongly correlated with XC skiing performance than those found for technique-specific modalities on roller skis. However, more sophisticated and mode-specific testing might be required for more homogenous groups of elite XC skiers.

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The Effects of a Short Specific Versus a Long Traditional Warm-Up on Time-Trial Performance in Cross-Country Skiing Sprint

International Journal of Sports Physiology and Performance ◽

10.1123/ijspp.2019-0618 ◽

2020 ◽

Vol 15 (7) ◽

pp. 941-948

Author(s):

Guro Strøm Solli ◽

Pål Haugnes ◽

Jan Kocbach ◽

Roland van den Tillaar ◽

Per Øyvind Torvik ◽

...

Keyword(s):

Heart Rate ◽

Time Trial ◽

Rating Of Perceived Exertion ◽

Warm Up ◽

Sprint Time ◽

Time Trial Performance ◽

Significant Difference ◽

Cross Country Skiing ◽

Cross Country ◽

Trial Performance

Purpose: To compare the effects of a short specific and a long traditional warm-up on time-trial performance in cross-country skiing sprint using the skating style, as well as related differences in pacing strategy and physiological responses. Methods: In total, 14 (8 men and 6 women) national-level Norwegian cross-country skiers (age 20.4 [3.1] y; VO2max 65.9 [5.7] mL/kg/min) performed 2 types of warm-up (short, 8 × 100 m with gradual increase from 60% to 95% of maximal speed with a 1-min rest between sprints, and long, ∼35 min at low intensity, including 5 min at moderate and 3 min at high intensity) in a randomized order with 1 hour and 40 minutes of rest between tests. Each warm-up was followed by a 1.3-km sprint time trial, with continuous measurements of speed and heart rate. Results: No difference in total time for the time trial between the short and long warm-ups (199 [17] vs 200 [16] s; P = .952), or average speed and heart rate for the total course, or in the 6 terrain sections (all P < .41, η2 < .06) was found. There was an effect of order, with total time-trial time being shorter during test 2 than test 1 (197 [16] vs 202 [16] s; P = .004). No significant difference in blood lactate and rating of perceived exertion was found between the short versus long warm-ups or between test 1 and test 2 at any of the measurement points during the test day (P < .58, η2 > .01). Conclusions: This study indicates that a short specific warm-up could be as effective as a long traditional warm-up during a sprint time trial in cross-country skiing.

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Comparison of Exclusive Double Poling to Classic Techniques of Cross-country Skiing

Medicine & Science in Sports & Exercise ◽

10.1249/mss.0000000000001840 ◽

2019 ◽

Vol 51 (4) ◽

pp. 760-772 ◽

Cited By ~ 6

Author(s):

THOMAS STÖGGL ◽

OLLI OHTONEN ◽

MASAKI TAKEDA ◽

NAOTO MIYAMOTO ◽

CORY SNYDER ◽

...

Keyword(s):

Double Poling ◽

Cross Country Skiing ◽

Cross Country

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Near Infrared Spectroscopy for Muscle Specific Analysis of Intensity and Fatigue during Cross-Country Skiing Competition—A Case Report

Sensors ◽

10.3390/s21072535 ◽

2021 ◽

Vol 21 (7) ◽

pp. 2535

Author(s):

Thomas Stöggl ◽

Dennis-Peter Born

Keyword(s):

Infrared Spectroscopy ◽

Near Infrared Spectroscopy ◽

Exercise Intensity ◽

Near Infrared ◽

Whole Body ◽

Long Distance ◽

Specific Loading ◽

Cross Country Skiing ◽

Cross Country ◽

Muscle Groups

The aims of the study were to assess the robustness and non-reactiveness of wearable near-infrared spectroscopy (NIRS) technology to monitor exercise intensity during a real race scenario, and to compare oxygenation between muscle groups important for cross-country skiing (XCS). In a single-case study, one former elite XCS (age: 39 years, peak oxygen uptake: 65.6 mL/kg/min) was equipped with four NIRS devices, a high-precision global navigation satellite system (GNSS), and a heart rate (HR) monitor during the Vasaloppet long-distance XCS race. All data were normalized to peak values measured during incremental laboratory roller skiing tests two weeks before the race. HR reflected changes in terrain and intensity, but showed a constant decrease of 0.098 beats per minute from start to finish. Triceps brachii (TRI) muscle oxygen saturation (SmO2) showed an interchangeable pattern with HR and seems to be less affected by drift across the competition (0.027% drop per minute). Additionally, TRI and vastus lateralis (VL) SmO2 revealed specific loading and unloading pattern of XCS in uphill and downhill sections, while rectus abdominus (RA) SmO2 (0.111% drop per minute) reflected fatigue patterns occurring during the race. In conclusion, the present preliminary study shows that NIRS provides a robust and non-reactive method to monitor exercise intensity and fatigue mechanisms when applied in an outdoor real race scenario. As local exercise intensity differed between muscle groups and central exercise intensity (i.e., HR) during whole-body endurance exercise such as XCS, NIRS data measured at various major muscle groups may be used for a more detailed analysis of kinetics of muscle activation and compare involvement of upper body and leg muscles. As TRI SmO2 seemed to be unaffected by central fatigue mechanisms, it may provide an alternative method to HR and GNSS data to monitor exercise intensity.

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Is There an Optimal Pole Length for Double Poling in Cross Country Skiing?

Journal of Applied Biomechanics ◽

10.1123/jab.2016-0071 ◽

2017 ◽

Vol 33 (3) ◽

pp. 197-202 ◽

Cited By ~ 8

Author(s):

Franziska Onasch ◽

Anthony Killick ◽

Walter Herzog

Keyword(s):

Oxygen Uptake ◽

Body Height ◽

Metabolic Cost ◽

Male Athletes ◽

Double Poling ◽

Acute Study ◽

Ground Contact Time ◽

Cross Country Skiing ◽

Cross Country ◽

The Given

The aim of this study was to determine the effects of pole length on energy cost and kinematics in cross country double poling. Seven sub-elite male athletes were tested using pole sets of different lengths (ranging between 77% and 98% of participants’ body height). Tests were conducted on a treadmill, set to a 2% incline and an approximate racing speed. Poling forces, contact times, and oxygen uptake were measured throughout the testing. Pole length was positively correlated with ground contact time (r = .57, p < .001) and negatively correlated with poling frequency (r = −.48, p = .003). Pole length was also positively correlated with pole recovery time and propulsive impulse produced per poling cycle (r = .36, p = .031; r = .35, p = .042, respectively). Oxygen uptake and pole length were negatively correlated (r = −.51, p = .004). This acute study shows that increasing pole length for double poling in sub-elite cross country skiers under the given conditions seems to change the poling mechanics in distinct ways, resulting in a more efficient poling action by decreasing an athlete’s metabolic cost.

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Choice of Pole and Ski Lengths Among Elite Cross-Country Skiers: The Influence of Sex and Performance Level

Frontiers in Sports and Active Living ◽

10.3389/fspor.2021.654864 ◽

2021 ◽

Vol 3 ◽

Author(s):

Per-Øyvind Torvik ◽

Roland van den Tillaar ◽

Øyvind Sandbakk

Keyword(s):

Body Height ◽

Sprint Performance ◽

Performance Level ◽

Whole Body ◽

Men And Women ◽

Male And Female ◽

Secondary Purpose ◽

Double Poling ◽

Cross Country ◽

And Performance

Cross-country (XC) skiers employ whole-body exercise to generate speed through poles and skis. The choice of optimal pole and ski lengths are therefore of high importance. The aim of this study was to document pole and ski lengths among elite male and female cross-country skiers in the classical and skating styles and to investigate sex differences in body-height-normalized pole and ski lengths. Our secondary purpose was to correlate body-height-normalized pole and ski lengths with performance level within both sexes. In total, Norwegian men and women (n = 87 and 36, respectively), participating in the Norwegian XC championship 2020, were investigated. Most athletes used poles close to the length allowed by the International Ski Federation (FIS) in the classical style among both sexes, with men using slightly longer poles than women (p < 0.05). Body-height-normalized pole lengths in skating were similar in men and women (around 90% of body height). Women used relatively longer ski lengths than men in both styles (p < 0.05). Women showed moderate correlations (r = 0.43, p < 0.05) between body-height-normalized pole lengths and sprint performance. Male and female cross-country skiers use as long classical ski poles as possible within the current regulations, while they use skating poles similar to recommendations given by the industry. The fact that men use longer body-height-normalized poles than women, where there is a correlation between pole length and sprint performance, indicate that faster women are able to better utilize the potential of using longer poles when double-poling. However, while women use relatively longer skis than men, no correlation with performance occurred for any of the sexes.

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The effects of carbohydrate ingestion on 30 minute rowing time trial performance

Comparative Exercise Physiology ◽

10.3920/cep140018 ◽

2014 ◽

Vol 10 (4) ◽

pp. 247-252

Author(s):

L. Bottoms ◽

R. Westhead ◽

J. Evans ◽

J. Blyth ◽

T. Sleet ◽

...

Keyword(s):

Perceived Exertion ◽

Time Trial ◽

Stroke Rate ◽

Current Investigation ◽

Ratings Of Perceived Exertion ◽

Carbohydrate Ingestion ◽

Time Trial Performance ◽

Maltodextrin Solution ◽

Carbohydrate Solution ◽

Trial Performance

The aim of the study was to determine whether ingestion of 6.4% carbohydrate solution prior to 30 min rowing had any effect on distance rowed. Twelve male participants (aged 22.21±2.47 years) volunteered to take part. Participants ingested either 500 ml of 6.4% flavourless maltodextrin solution (CHO) or water (PLA) prior to exercise. During 30 min of self-paced rowing heart rate (HR), ratings of perceived exertion (RPE), stroke rate, power output and distance covered were recorded every 6-min throughout. Participants rowed significantly (P<0.05) further during the CHO trial (6,714.2±409.9 m) compared to the PLA trial (6,390.8±448.1 m). Power also increased during the CHO trial compared to the PLA (P<0.05). However, there was no difference in RPE. In conclusion, from the current investigation rowers who wish to improve their time trial performance in longer duration events may benefit from the ingestion of CHO prior to competition.

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