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5. Impact of Menstrual cycle-based Periodized training on Aerobic performance, a Clinical Trial study protocol—the IMPACT study

Author

Ekenros, L., von Rosen, P., Norrbom, J., Holmberg, H. -C, Sundberg, C. J., Fridén, C., Hirschberg, A. L., Ekenros, L., von Rosen, P., Norrbom, J., Holmberg, H. -C, Sundberg, C. J., Fridén, C., and Hirschberg, A. L.

Abstract

Background: The menstrual cycle and its impact on training and performance are of growing interest. However, evidence is lacking whether periodized exercise based on the menstrual cycle is beneficial. The primary purpose of this proposed randomized, controlled trial, the IMPACT study, is to evaluate the effect of exercise periodization during different phases of the menstrual cycle, i.e., comparing follicular phase-based and luteal phase-based training with regular training during the menstrual cycle on physical performance in well-trained women. Methods: Healthy, well-trained, eumenorrheic women between 18 and 35 years (n = 120) will be recruited and first assessed for physical performance during a run-in menstrual cycle at different cycle phases and then randomized to three different interventions: follicular phase-based training, luteal phase-based training, or regular training during three menstrual cycles. The training intervention will consist of high-intensity spinning classes followed by strength training. The menstrual cycle phases will be determined by serum hormone analysis throughout the intervention period. Assessment of aerobic performance (primary outcome) and muscle strength, body composition, and blood markers will be performed at baseline and at the end of the intervention. Discussion: With a robust methodology, this study has the potential to provide evidence of the differential effects of exercise periodization during different phases of the menstrual cycle in female athletes. Trial registration: ClinicalTrials.gov NCT05697263 . Registered on 25 January 2023

Published
2024
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8. Advanced energy-saving optimization strategy in thermo-mechanical pulping by machine learning approach

Author

Talebjedi, B., Laukkanen, T., Holmberg, H., Vakkilainen, E., Syri, S., Department of Mechanical Engineering, LUT University, Aalto-yliopisto, and Aalto University

Subjects
forest industry, PREDICTION, data analysis, REFINING PROCESS, Forestry, MULTIPLE-REGRESSION ANALYSIS, refining energy simulation, machine learning, MILL, QUALITY, General Materials Science, NEURAL-NETWORKS, artificial neural network, thermo-mechanical pulping
Abstract

Thermo-mechanical Pulping (TMP) is one of the most energy-intensive industries where most of the electrical energy is consumed in the refining process. This paper proposes the energy-saving refining optimization strategy by integrating the machine learning algorithm and heuristic optimization method. First, refining specific energy consumption (RSEC) and pulp quality identification models are developed using Artificial Neural Networks. In the second step, the developed identification models are incorporated with the Genetic algorithm to minimize the total refining specific energy consumption while maintaining the same pulp quality. Simulation results prove that a deep multilayer perceptron neural network is a powerful tool for creating refining energy and quality identification models with the model correlation coefficients of 0.97, 0.94, 0.92, and 0.67 for the first-stage RSEC, second-stage RSEC, final pulp fiber length, and freeness prediction, respectively. Findings confirm that the average total RSEC reduction of 14 % is achievable by utilizing the proposed optimization method.

Published
2022

18. A Scientific Perspective on Reducing Ski-Snow Friction to Improve Performance in Olympic Cross-Country Skiing, the Biathlon and Nordic Combined

Author

Almqvist, Andreas, Pellegrini, Barbara, Lintzén, Nina, Emami, Nazanin, Holmberg, H-C, and Larsson, Roland

Subjects
skiing, friction, tribology, speed, General Medicine, snow, biomechanics, equipment, gliding
Abstract

Of the medals awarded at the 2022 Winter Olympics in Beijing, 24% were for events involving cross-country skiing, the biathlon and Nordic combined. Although much research has focused on physiological and biomechanical characteristics that determine success in these sports, considerably less is yet known about the resistive forces. Here, we specifically describe what is presently known about ski-snow friction, one of the major resistive forces. Today, elite ski races take place on natural and/or machine-made snow. Prior to each race, several pairs of skis with different grinding and waxing of the base are tested against one another with respect to key parameters, such as how rapidly and for how long the ski glides, which is dependent on ski-snow friction. This friction arises from a combination of factors, including compaction, plowing, adhesion, viscous drag, and water bridging, as well as contaminants and dirt on the surface of and within the snow. In this context the stiffness of the ski, shape of its camber, and material composition and topography of the base exert a major influence. An understanding of the interactions between these factors, in combination with information concerning the temperature and humidity of both the air and snow, as well as the nature of the snow, provides a basis for designing specific strategies to minimize ski-snow friction. In conclusion, although performance on “narrow skis” has improved considerably in recent decades, future insights into how best to reduce ski-snow friction offer great promise for even further advances.

Published
2022

19. A Comparison of a Novel Stretchable Smart Patch for Measuring Runner’s Step Rates with Existing Measuring Technologies

Author

Verdel, Nina, Drobnić, M., Maslik, J., Rahimi, K. B., Tantillo, G., Gumiero, A., Hjort, K., Holmberg, H. -C, Supej, Matej, Verdel, Nina, Drobnić, M., Maslik, J., Rahimi, K. B., Tantillo, G., Gumiero, A., Hjort, K., Holmberg, H. -C, and Supej, Matej

Abstract

A novel wearable smart patch can monitor various aspects of physical activity, including the dynamics of running, but like any new device developed for such applications, it must first be tested for validity. Here, we compare the step rate while running in place as measured by this smart patch to the corresponding values obtained utilizing "gold standard" MEMS accelerometers in combination with bilateral force plates equipped with HBM load cells, as well as the values provided by a three-dimensional motion capture system and the Garmin Dynamics Running Pod. The 15 healthy, physically active volunteers (age = 23 ± 3 years; body mass = 74 ± 17 kg, height = 176 ± 10 cm) completed three consecutive 20-s bouts of running in place, starting at low, followed by medium, and finally at high intensity, all self-chosen. Our major findings are that the rates of running in place provided by all four systems were valid, with the notable exception of the fast step rate as measured by the Garmin Running Pod. The lowest mean bias and LoA for these measurements at all rates were associated consistently with the smart patch.

Published
2022
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20. Topic: Inguinal Hernia — Primary inguinal hernia, state of the art in the different socio economic reality

Author

Lubrano, T., Vidotto, C., Falcone, A., Grasso, L., G, F., Morino, M., Techapongsatorn, S., Tansawet, Amarit, Lerdsirisopon, Sopon, Kasetsermwiriya, Wisit, Srimontayamas, Satit, Loapeamthong, Ched-U-Sa, Teawprasert, Piya, Takehara, H., Nishihara, M., Kuniyoshi, F., Miyahira, T., Hanashiro, N., Takushi, Y., Aka, H., Nakagawa, H., Shiraishi, M., Okushima, N., Soler, M., Oyama, R., Chihara, N., Suzuki, H., Watanabe, M., Nakata, R., Uchida, E., Mitura, K., Koziel, S., Pasierbek, M., Maietta, P., Iannace, C., Lee, H., Cho, H., Jovanovic, S., Pejcic, V., Trenkic, M., Filipovic, N., Pavlovic, A., Jovanovc, B., Hemberg, A., Nordin, P., Holmberg, H., De Rosa, A., Meyer, A., Seabra, A. P., Sorge, A., Hack, J., Soares, L. A. N. G., Chalub, S. R. S., Malcher, R., Kingsnorth, A., Dabic, D., Maric, B., Perunicic, V., Kocaay, A. F., Eker, T., Celik, S. U., Akyol, C., Cakmak, A., Contino, E., Molinari, P., Lanza, C., Binda, M., Livraghi, L., Farassino, L., Cocozza, E., Crespi, A., Ambrosoli, A., Zhao, Y., Li, J. W., and Zheng, M. H.

Published
2015
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21. Topic: Inguinal Hernia — Post op chronic pain: incidence, evaluation, legal consequences, therapy, follow up

Author

Zwaans, W., Verhagen, T., Roumen, R., Scheltinga, M., Dieleman, J., Vad, M., Frost, P., Rosenberg, J., Svendsen, S. W., Tabbara, M., Carandina, S., Bossi, M., Polliand, C., Barrat, C., Soler, M., Chander, J., Sharma, R., Lal, R., Pradhan, G., Mol, F., Mitura, K., Romanczuk, M., Lundstrom, K., Nordin, P., Holmberg, H., Sahin, A., Kulacoglu, H., Olcucuoglu, E., Guadalaxara, A., Rampinelli, L. A., Mariani, P., Ubezio, D., Felici, A., Santagati, G., Novellino, L., Gitelis, M., DeAsis, F., Chao, S., Lapin, B., Denham, W., Linn, J., Haggerty, S., Carbray, J., Ujiki, M., Evans, L., Canciani, G. N., Gordon, E. M., Wei, P., Tam, K., Chen, C., Kao, C., Protasov, A., Bogdanov, D., Meshkov, M., Kurganov, I., Misra, M. C., Bansal, V. K., Subodh, K., Krishna, A., Bansal, D., Ray, S., Rajeshwari, S., Marzo, F., Forni, S., Massi, M., Gia, L., and Dabrowski, A.

Published
2015
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22. Topic: Inguinal Hernia — Recurrences: incidence, approach, follow up

Author

Wang, Y. C., Huang, C. S., Uen, Y., Tan, W. B., Tang, S. W., Clara, E. Sta., Hu, J., Wijerathne, S., Shabbir, A., Lomanto, D., Pathiranage, M. Simon Meru, Perera, K. S., Wijemanna, A., Doerhoff, C., Bringman, S., Romanowski, C., Jones, P., Lerchuk, O., Lukavetskyy, O., Khomyak, V., Shavarov, Y., Chykaylo, A., Porytskyy, A., Kinaci, E., Ates, M., Dirican, A., Sarici, B., Soyer, V., Kose, E., Isik, B., Curado-Soriano, A., Infantes-Ormad, M., Valera-Sanchez, A., Dominguez-Amodeo, A., Naranjo-Fernandez, J. R., Zafra, A. Ruiz, Navarrete-Carcer, E., Oliva-Mompean, F., Padillo-Ruiz, J., Burcharth, J., Andresen, K., Pommergaard, H.-C., Bisgaard, T., Rosenberg, J., Berrevoet, F., Denys, C., Berghog, J., Nillson, H., Nordin, P., Holmberg, H., Amiki, M., Crespi, A., Ferioli, M., Del Bosco, A., Lanza, C., Binda, M., Latham, L., Berselli, M., Cocozza, E., Ambrosoli, A., Chen, K. H., Chio, U. C., Siow, T. F., Wu, J. M., Chen, Y. D., Lin, T. C., Huang, S. Y., Jeng, K. S., Liang, Cun He, Tang, Jian-Xiong, and Jang, Jun

Published
2015
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29. Energy simulation and variable analysis of refining process in thermo-mechanical pulp mill using machine learning approach

Author

Talebjedi, B., Laukkanen, T., Holmberg, H., LUT, E., Syri, S., Department of Mechanical Engineering, LUT University, Aalto-yliopisto, and Aalto University

Subjects
refining energy simulation, NEURAL-NETWORK, EFFICIENCY, Thermo-mechanical pulping, PREDICTION, refining parametric study, data analysis, QUALITY, multilayer perceptron, artificial intelligence, MULTIPLE-REGRESSION ANALYSIS
Abstract

Funding Information: The authors gratefully acknowledge the support of the Academy of Finland [grant number 315020]. Publisher Copyright: © 2021 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group. Data from two thermo-mechanical pulp mills are collected to simulate the refining process using deep learning. A multilayer perceptron neural network is utilized for pattern recognition of the refining variables. Results show the impressive capability of artificial intelligence methods in refining energy simulation so that the correlation coefficient of 98% is accessible. A comprehensive parametric study has been made to investigate the effect of refining disturbance variables, plate gap and dilution water on refining energy simulation. The generated model reveals the non-linear hidden pattern between refining variables, which can be used for optimal refining control strategy. Considering the disturbance variables' effect in refining energy simulation, model accuracy could increase by 15%. Removing the plate gape from predictive variables reduces the simulation determination coefficient by up to 25% in both mills, while the mentioned value for removing dilution water is 9-17% in mill 1 and about 35% in mill 2.

Published
2021

34. Mitochondrial oxygen affinity increases after sprint interval training and is related to the improvement in peak oxygen uptake.

Author

Larsen, Filip J, Schiffer, T A, Zinner, C, Willis, S J, Morales-Alamo, D, Calbet, Jal, Boushel, R, Holmberg, H C, Larsen, Filip J, Schiffer, T A, Zinner, C, Willis, S J, Morales-Alamo, D, Calbet, Jal, Boushel, R, and Holmberg, H C

Abstract

AIMS: The body responds to exercise training by profound adaptations throughout the cardiorespiratory and muscular systems, which may result in improvements in maximal oxygen consumption (VO2 peak) and mitochondrial capacity. By convenience, mitochondrial respiration is often measured at supra-physiological oxygen levels, an approach that ignores any potential regulatory role of mitochondrial affinity for oxygen (p50mito ) at physiological oxygen levels. METHODS: In this study, we examined the p50mito of mitochondria isolated from the Vastus lateralis and Triceps brachii in 12 healthy volunteers before and after a training intervention with 7 sessions of sprint interval training using both leg cycling and arm cranking. The changes in p50mito were compared to changes in whole-body VO2 peak. RESULTS: We here show that p50mito is similar in isolated mitochondria from the Vastus (40 ± 3.8 Pa) compared to Triceps (39 ± 3.3) but decreases (mitochondrial oxygen affinity increases) after 7 sessions of sprint interval training (to 26 ± 2.2 Pa in Vastus and 22 ± 2.7 Pa in Triceps, both p<0.01). The change in VO2 peak modeled from changes in p50mito was correlated to actual measured changes in VO2 peak (R2 =0.41, p=0.002). CONCLUSION: Together with mitochondrial respiratory capacity, p50mito is a critical factor when measuring mitochondrial function, it can decrease with sprint interval training and should be considered in the integrative analysis of the oxygen cascade from lung to mitochondria.

Published
2020
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37. Why do arms extract less oxygen than legs during exercise?

Author

Calbet, J.A.L., Holmberg, H.-C., Rosdahl, H., van Hall, G., Jensen-Urstad, M., and Saltin, B.

Subjects
Blood flow -- Research, Fatigue -- Research, Biological sciences
Abstract

To determine whether conditions for [O.sub.2] utilization and [O.sub.2] off-loading from the hemoglobin are different in exercising arms and legs, six cross-country skiers participated in this study. Femoral and subclavian vein blood flow and gases were determined during skiing on a treadmill at ~76% maximal [O.sub.2] uptake (V[O.sub.2 max]) and at V[O.sub.2 max] with different techniques: diagonal stride (combined arm and leg exercise), double poling (predominantly arm exercise), and leg skiing (predominantly leg exercise). The percentage of [O.sub.2] extraction was always higher for the legs than for the arms. At maximal exercise (diagonal stride), the corresponding mean values were 93 and 85% (n = 3; P < 0.05). During exercise, mean arm [O.sub.2] extraction correlated with the P[O.sub.2] value that causes hemoglobin to be 50% saturated ([P.sub.50]: r = 0.93, P < 0.05), but for a given value of [P.sub.50], [O.sub.2] extraction was always higher in the legs than in the arms. Mean capillary muscle [O.sub.2] conductance of the arm during double poling was 14.5 (SD 2.6) ml x [min.sup.-1] x mm[Hg.sup.-1], and mean capillary P[o.sub.2] was 47.7 (SD 2.6) mmHg. Corresponding values for the legs during maximal exercise were 48.3 (SD 13.0) ml x [min.sup.-1]. mm[Hg.sup.-1] and 33.8 (SD 2.6) mmHg, respectively. Because conditions for [O.sub.2] off-loading from the hemoglobin are similar in leg and arm muscles, the observed differences in maximal arm and leg [O.sub.2] extraction should be attributed to other factors, such as a higher heterogeneity in blood flow distribution, shorter mean transit time, smaller diffusing area, and larger diffusing distance, in arms than in legs. diffusing capacity; fatigue; oxygen extraction; performance; training

Published
2005

43. Leg and arm lactate and substrate kinetics during exercise

Author

Van Hall, G., Jensen-Urstad, M., Rosdahl, H., Holmberg, H.-C., Saltin, B., and Calbet, J.A.L.

Subjects
Exercise -- Physiological aspects, Muscles -- Physiological aspects, Biological sciences
Abstract

To study the role of muscle mass and muscle activity on lactate and energy kinetics during exercise, whole body and limb lactate, glucose, and fatty acid fluxes were determined in six elite cross-country skiers during roller-skiing for 40 min with the diagonal stride (Continuous Arm + Leg) followed by 10 min of double poling and diagonal stride at 72-76% maximal [O.sub.2] uptake. A high lactate appearance rate ([R.sub.a] 184 [+ or -] 17 [micro]mol*[kg.sup.-1]*[min.sup.-1]) but a low arterial lactate concentration (~2.5 mmol/l) were observed during Continuous Arm + Leg despite a substantial net lactate release by the arm of ~2.1 mmol/min, which was balanced by a similar net lactate uptake by the leg. Whole body and limb lactate oxidation during Continuous Arm + Leg was ~45% at rest and ~95% of disappearance rate and limb lactate uptake, respectively. Limb lactate kinetics changed multiple times when exercise mode was changed. Whole body glucose and glycerol turnover was unchanged during the different skiing modes; however, limb net glucose uptake changed severalfold. In conclusion, the arterial lactate concentration can be maintained at a relatively low level despite high lactate [R.sub.a], during exercise with a large muscle mass because of the large capacity of active skeletal muscle to take up lactate, which is tightly correlated with lactate delivery. The limb lactate uptake during exercise is oxidized at rates far above resting oxygen consumption, implying that lactate uptake and subsequent oxidation are also dependent on an elevated metabolic rate. The relative contribution of whole body and limb lactate oxidation is between 20 and 30% of total carbohydrate oxidation at rest and during exercise under the various conditions. Skeletal muscle can change its limb net glucose uptake severalfold within minutes, causing a redistribution of the available glucose because whole body glucose turnover was unchanged. lactate dehydrogenase; cross-country skiing; tracers

Published
2003

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