The Effect of Polarized Training on the Athletic Performance of Male and Female Cross-Country Skiers during the General Preparation Period
Abstract
:1. Introduction
2. Methods
2.1. Participants
2.2. Design and Procedures
2.3. Anthropometric Measurements and Body Composition
2.4. Graded Exercise Test
2.5. Ski Ergometer Test
2.6. Training Program
2.7. Statistical Analysis
3. Results
4. Discussion
5. Conclusions
Author Contributions
Funding
Institutional Review Board Statement
Informed Consent Statement
Data Availability Statement
Conflicts of Interest
References
- Mahood, N.V.K.; Robert, W.; Kertzer, R.; Quinn, T.J. Physiological determinants of cross-country ski racing performance. Med. Sci. Sports Exerc. 2001, 33, 1379–1384. [Google Scholar] [CrossRef]
- Sandbakk, Ø.; Holmberg, H.-C. A reappraisal of success factors for Olympic cross-country skiing. Int. J. Sports Physiol. Perform. 2014, 9, 117–121. [Google Scholar] [CrossRef]
- Sandbakk, Ø.; Ettema, G.; Holmberg, H.-C. Gender differences in endurance performance by elite cross-country skiers are influenced by the contribution from poling. Scand. J. Med. Sci. Sports 2014, 24, 28–33. [Google Scholar] [CrossRef] [PubMed]
- Holmberg, H.C.; Rosdahl, H.; Svedenhag, J. Lung function, arterial saturation and oxygen uptake in elite cross country skiers: Influence of exercise mode. Scand. J. Med. Sci. Sports 2007, 17, 437–444. [Google Scholar] [CrossRef] [PubMed]
- Jones, A.M.; Carter, H. The effect of endurance training on parameters of aerobic fitness. Sports Med. 2000, 29, 373–386. [Google Scholar] [CrossRef] [PubMed]
- Sandbakk, Ø.; Holmberg, H.-C.; Leirdal, S.; Ettema, G. The physiology of world-class sprint skiers. Scand. J. Med. Sci. Sports 2011, 21, e9–e16. [Google Scholar] [CrossRef]
- Staib, J.L.; Im, J.; Caldwell, Z.; Rundell, K.W. Cross-country ski racing performance predicted by aerobic and anaerobic double poling power. J. Strength Cond. Res. 2000, 14, 282–288. [Google Scholar]
- Stöggl, T.; Mueller, E.; Ainegren, M.; Holmberg, H.-C. General strength and kinetics: Fundamental to sprinting faster in cross country skiing? Scand. J. Med. Sci. Sports 2011, 21, 791–803. [Google Scholar] [CrossRef] [PubMed]
- McGawley, K.; Holmberg, H.-C. Aerobic and anaerobic contributions to energy production among junior male and female cross-country skiers during diagonal skiing. Int. J. Sports Physiol. Perform. 2014, 9, 32–40. [Google Scholar] [CrossRef] [PubMed] [Green Version]
- Akay, M.F.; About, F.; Özçiloğlu, M.; Heil, D. Identifying the discriminative predictors of upper body power of cross-country skiers using support vector machines combined with feature selection. Neural Comput. Appl. 2016, 27, 1785–1796. [Google Scholar] [CrossRef]
- Danielsen, J.; Sandbakk, Ø.; McGhie, D.; Ettema, G. The effect of exercise intensity on joint power and dynamics in ergometer double-poling performed by cross-country skiers. Hum. Mov. Sci. 2018, 57, 83–93. [Google Scholar] [CrossRef]
- Terzis, G.; Stattin, B.; Holmberg, H.-C. Upper body training and the triceps brachii muscle of elite cross country skiers. Scand. J. Med. Sci. Sports 2006, 16, 121–126. [Google Scholar] [CrossRef]
- Sandbakk, Ø.; Hegge, A.M.; Losnegard, T.; Skattebo, Ø.; Tønnessen, E.; Holmberg, H.-C. The physiological capacity of the world’s highest ranked female cross-country skiers. Med. Sci. Sports Exerc. 2016, 48, 1091–1100. [Google Scholar] [CrossRef] [PubMed] [Green Version]
- Tonkonogi, M.; Walsh, B.; Svensson, M.; Sahlin, K. Mitochondrial function and antioxidative defence in human muscle: Effects of endurance training and oxidative stress. J. Physiol. 2000, 528, 379–388. [Google Scholar] [CrossRef] [PubMed]
- Aagaard, P.; Andersen, J.L. Effects of strength training on endurance capacity in top-level endurance athletes. Scand. J. Med. Sci. Sports 2010, 20, 39–47. [Google Scholar] [CrossRef] [PubMed]
- Docherty, D.; Sporer, B. A proposed model for examining the interference phenomenon between concurrent aerobic and strength training. Sports Med. 2000, 30, 385–394. [Google Scholar] [CrossRef] [PubMed]
- Stöggl, T.; Sperlich, B. Polarized training has greater impact on key endurance variables than threshold, high intensity, or high volume training. Front. Physiol. 2014, 5, 33. [Google Scholar] [CrossRef] [Green Version]
- Seiler, K.S.; Kjerland, G.Ø. Quantifying training intensity distribution in elite endurance athletes: Is there evidence for an “optimal” distribution? Scand. J. Med. Sci. Sports 2006, 16, 49–56. [Google Scholar] [CrossRef]
- Rønnestad, B.R.; Hansen, J.; Thyli, V.; Bakken, T.A.; Sandbakk, Ø. 5-week block periodization increases aerobic power in elite cross-country skiers. Scand. J. Med. Sci. Sports 2016, 26, 140–146. [Google Scholar] [CrossRef]
- Gorostiaga, E.M.; Walter, C.B.; Foster, C.; Hickson, R.C. Uniqueness of interval and continuous training at the same maintained exercise intensity. Eur. J. Appl. Physiol. Occup. Physiol. 1991, 63, 101–107. [Google Scholar] [CrossRef]
- Solli, G.S.; Tønnessen, E.; Sandbakk, Ø. The training characteristics of the world’s most successful female cross-country skier. Frontiers Physiol. 2017, 8, 1069. [Google Scholar] [CrossRef] [Green Version]
- Hoff, J.; Gran, A.; Helgerud, J. Maximal strength training improves aerobic endurance performance. Scand. J. Med. Sci. Sports 2002, 12, 288–295. [Google Scholar] [CrossRef]
- Losnegard, T.; Mikkelsen, K.; Rønnestad, B.R.; Hallén, J.; Rud, B.; Raastad, T. The effect of heavy strength training on muscle mass and physical performance in elite cross country skiers. Scand. J. Med. Sci. Sports 2011, 21, 389–401. [Google Scholar] [CrossRef]
- Storen, O.; Helgerud, J.; Stoa, E.M.; Hoff, J. Maximal strength training improves running economy in distance runners. Med. Sci. Sports Exerc. 2008, 40, 1089–1094. [Google Scholar] [CrossRef] [PubMed] [Green Version]
- García-Pallarés, J.; García-Fernández, M.; Sánchez-Medina, L.; Izquierdo, M. Performance changes in world-class kayakers following two different training periodization models. Eur. J. Appl. Physiol. 2010, 110, 99–107. [Google Scholar] [CrossRef] [PubMed]
- Seiler, S. What is best practice for training intensity and duration distribution in endurance athletes? Int. J. Sports Physiol. Perform. 2010, 5, 276–291. [Google Scholar] [CrossRef]
- Plews, D.J.; Laursen, P.B.; Kilding, A.E.; Buchheit, M. Heart-rate variability and training-intensity distribution in elite rowers. Int. J. Sports Physiol. Perform. 2014, 9, 1026–1032. [Google Scholar] [CrossRef]
- Hausswirth, C.; Louis, J.; Aubry, A.; Bonnet, G.; Duffield, R.; Le Meur, Y. Evidence of disturbed sleep and increased illness in overreached endurance athletes. Med. Sci. Sports Exerc. 2014, 46, 1036–1045. [Google Scholar] [CrossRef]
- Turner, A. The science and practice of periodization: A brief review. Strength Cond. J. 2011, 33, 34–46. [Google Scholar] [CrossRef] [Green Version]
- Lyakh, V.; Mikołajec, K.; Bujas, P.; Litkowycz, R. Review of Platonov’s “Sports Training Periodization. General Theory and its Practical Application”—Kiev: Olympic Literature, 2013. J. Hum. Kinet. 2014, 44, 259–263. [Google Scholar] [CrossRef] [PubMed] [Green Version]
- George, J.D.; Paul, S.L.; Hyde, A.; Bradshaw, D.I.; Vehrs, P.R.; Hager, R.L.; Yanowitz, F.G. Prediction of maximum oxygen uptake using both exercise and non-exercise data. Meas. Phys. Educ. Exerc. Sci. 2009, 13, 1–12. [Google Scholar] [CrossRef]
- Bruce, R.A.; Kusumi, F.; Hosmer, D. Maximal oxygen intake and nomographic assessment of functional aerobic impairment in cardiovascular disease. Am. Heart J. 1973, 85, 546–562. [Google Scholar] [CrossRef]
- Will, P.M.; Walter, J.D. Exercise testing: Improving performance with a ramped Bruce protocol. Am. Heart J. 1999, 138, 1033–1037. [Google Scholar] [CrossRef]
- Klusiewicz, A.; Faff, J.; Starczewska-Czapowska, J. Prediction of maximal oxygen uptake from submaximal and maximal exercise on a ski ergometer. Biol. Sport 2011, 28, 31–35. [Google Scholar] [CrossRef] [Green Version]
- Bortolan, L.; Pellegrini, B.; Finizia, G.; Schena, F. Assessment of the reliability of a custom built Nordic Ski Ergometer for cross-country skiing power test. J. Sports Med. Phys. Fit. 2008, 48, 177–182. [Google Scholar]
- Carlsson, T.; Wedholm, L.; Nilsson, J.; Carlsson, M. The effects of strength training versus ski-ergometer training on double-poling capacity of elite junior cross-country skiers. Eur. J. Appl. Physiol. 2017, 117, 1523–1532. [Google Scholar] [CrossRef]
- Choi, Y.C.; Kim, J.K. The Effect of Short-Term Summer Ski Training on Body Composition, Physical Fitness, and Isokinetic Muscle Function of Cross-Country Skiers. J. Mens Health 2020, 16, e63–e74. [Google Scholar]
- Neal, C.M.; Hunter, A.M.; Brennan, L.; O’Sullivan, A.; Hamilton, D.L.; DeVito, G.; Galloway, S.D.R. Six weeks of a polarized training-intensity distribution leads to greater physiological and performance adaptations than a threshold model in trained cyclists. J. Appl. Physiol. 2013, 114, 461–471. [Google Scholar] [CrossRef] [PubMed] [Green Version]
- Rosenblat, M.A.; Perrotta, A.S.; Vicenzino, B. Polarized vs. threshold training intensity distribution on endurance sport performance: A systematic review and meta-analysis of randomized controlled trials. J. Strength Cond. Res. 2019, 33, 3491–3500. [Google Scholar] [CrossRef] [PubMed]
- Rodriguez, N.R.; Di Marco, N.M.; Langley, S. American College of Sports Medicine position stand. Nutrition and athletic performance. Med. Sci. Sports Exerc. 2009, 41, 709. [Google Scholar] [PubMed]
- Loucks, A.B. Energy balance and body composition in sports and exercise. J. Sports Sci. 2004, 22, 1–14. [Google Scholar] [CrossRef]
- Silvestre, R.; West, C.; Maresh, C.M.; Kraemer, W.J. Body Composition and Physical Performance in Men’s Soccer: Astudy Of A National Collegiate Athletic Association Division Iteam. J. Strength Cond. Res. 2006, 20, 177–183. [Google Scholar] [CrossRef] [PubMed]
- Fleck, S.J. Body composition of elite American athletes. Am. J. Sports Med. 1983, 11, 398–403. [Google Scholar] [CrossRef] [PubMed]
- Stöggl, T.; Enqvist, J.; Müller, E.; Holmberg, H.-C. Relationships between body composition, body dimensions, and peak speed in cross-country sprint skiing. J. Sports Sci. 2010, 28, 161–169. [Google Scholar] [CrossRef]
- Ranković, G.; Mutavdžić, V.; Toskić, D.; Preljević, A.; Kocić, M.; Nedin-Ranković, G.; Damjanović, N. Aerobic capacity as an indicator in different kinds of sports. Bosn. J. Basic Med. Sci. 2010, 10, 44. [Google Scholar] [CrossRef] [Green Version]
- Ponorac, N.; Matavulj, A.; Grujić, N.; Rajkovača, Z.; Kovačević, P. Maximal oxygen uptake (VO2max) as the indicator of physical working capacity in sportsmen. Acta Med. Median. 2005, 44, 17–20. [Google Scholar]
- Durkalec-Michalski, K.; Podgorski, T.; Sokolowski, M.; Jeszka, J. Relationship between body composition indicators and physical capacity of the combat sports athletes. Arch. Budo 2016, 12, 247–256. [Google Scholar]
- Rusko, H. Handbook of Sports Medicine and Science, Cross Country Skiing; Blackwell Publishing: Hoboken, NJ, USA, 2008; pp. 1–31. [Google Scholar]
- Fleck, S.J. Periodized strength training: A critical review. J. Strength Cond. Res. 1999, 13, 82–89. [Google Scholar] [CrossRef]
- Daussin, F.N.; Zoll, J.; Dufour, S.P.; Ponsot, E.; Lonsdorfer-Wolf, E.; Doutreleau, S.; Mettauer, B.; Piquard, F.; Geny, B.; Richard, R. Effect of interval versus continuous training on cardiorespiratory and mitochondrial functions: Relationship to aerobic performance improvements in sedentary subjects. Am. J. Physiol. Regul. Integr. Comp. Physiol. 2008, 295, R264–R272. [Google Scholar] [CrossRef] [PubMed] [Green Version]
- Astorino, T.A.; Edmunds, R.M.; Clark, A.; King, L.; Gallant, R.A.; Namm, S.; Fischer, A.; Wood, K.M. High-intensity interval training increases cardiac output and VO2max. Med. Sci. Sports Exerc. 2017, 49, 265–273. [Google Scholar] [CrossRef]
- Jeukendrup, A.; Diemen, A.V. Heart rate monitoring during training and competition in cyclists. J. Sports Sci. 1998, 16, 91–99. [Google Scholar] [CrossRef]
- Achten, J.; Jeukendrup, A.E. Heart rate monitoring. Sports Med. 2003, 33, 517–538. [Google Scholar] [CrossRef] [PubMed]
- Benson, R.; Connolly, D. Heart Rate Training; Human Kinetics: Champaign, IL, USA, 2019. [Google Scholar]
- Sylta, Ø.; Tønnessen, E.; Seiler, S. From heart-rate data to training quantification: A comparison of 3 methods of training-intensity analysis. Int. J. Sports Physiol. Perform. 2014, 9, 100–107. [Google Scholar] [CrossRef] [PubMed] [Green Version]
- Levine, B.D.; Stray-Gundersen, J. “Living high-training low”: Effect of moderate-altitude acclimatization with low-altitude training on performance. J. Appl. Physiol. 1997. [Google Scholar] [CrossRef]
- Truijens, M.J.; Toussaint, H.M.; Dow, J.; Levine, B.D. Effect of high-intensity hypoxic training on see-level swimming performances. J. Appl. Physiol. 2003, 94, 733–743. [Google Scholar] [CrossRef] [PubMed] [Green Version]
- Lee, B.W.; Kim, J.K.; Kwon, H.J.; Choi, Y.C. Effects of Living Low and Training High on Body Composition, Exercise Performance, Blood CK, Lactate and Oxidative Stress Makers Responses in Cross Country Skiers. J. Sports Leis. Stud. 2013, 53, 659–710. [Google Scholar]
- Larsson, P.; Olofsson, P.; Jakobsson, E.; Burlin, L.; Henriksson-Larsén, K. Physiological predictors of performance in cross-country skiing from treadmill tests in male and female subjects. Scand. J. Med. Sci. Sports 2002, 12, 347–353. [Google Scholar] [CrossRef]
- MacDougall, J.D.; Wenger, H.A. Physiological Testing of the High-Performance Athlete; Human Kinetics Books: Champaign, IL, USA, 1991. [Google Scholar]
- Alsobrook, N.G.; Heil, D.P. Upper body power as a determinant of classical cross-country ski performance. Eur. J. Appl. Physiol. 2009, 105, 633–641. [Google Scholar] [CrossRef] [PubMed]
- Forbes, S.C.; Chilibeck, P.D.; Craven, B.; Bhambhani, Y. Comparison of a double poling ergometer and field test for elite cross country sit skiers. N. Am. J. Sports Phys. Ther. NAJSPT 2010, 5, 40. [Google Scholar]
- Fukuda, D.H.; Hetrick, R.P.; Kendall, K.L.; Smith-Ryan, A.E.; Jackson, M.E.; Stout, J.R. Characterization of the work–time relationship during cross-country ski ergometry. Physiol. Meas. 2013, 35, 31. [Google Scholar] [CrossRef] [PubMed]
Sex (n) | Age (yrs) | Height (cm) | Weight (kg) | Body Fat (%) | Muscle Mass (kg) |
---|---|---|---|---|---|
Male (8) | 22.7 ± 3.4 | 171.5 ± 6.6 | 72.2 ± 5.19 | 18.1 ± 7.12 | 34.1 ± 2.68 |
Female (8) | 24.1 ± 4.3 | 162 ± 6.0 | 57.3 ± 5.96 | 25.2 ± 4.3 | 29.1 ± 7.7 |
Day | Variables | A.M. Training | P.M. Training | |||||
---|---|---|---|---|---|---|---|---|
Mon | Event | Roller Classical | Trekking Run | |||||
Time | 40-22-30 min speed 10 s (ex)/120 s (re) × 10 set | 90 min | ||||||
Intensity | zone 2-5-1 | zone 1 | ||||||
Tue | Event | Roller Skate | Weight Training + Core Training | |||||
Time | 40-20-40 min | 90 min | ||||||
Intensity | zone 2-3-1 | 65%(1RM) × 15rd × 3 set recovery time 90 s | ||||||
Wed | Event | Mountain Pole Walk | REST | |||||
Time | 180 min | |||||||
Intensity | zone 1 | |||||||
Thu | Event | Roller Classical | OTHER SPORTS (fun sports) | |||||
Time | 90 min | 90 min | ||||||
Intensity | zone 2 | FREE | ||||||
Fri | Event | Roller Skate | Weight Training + Core Training | |||||
Time | 40-40-30 min (5 min(ex)/3 min(re) × 5 set) | 90 min | ||||||
Intensity | zone 2-4-1 | 65%(1RM) × 15rd × 3 set recovery time 90 s | ||||||
Sat | Event | BIKE | Rest | |||||
Time | 180 min | |||||||
Intensity | zone 1 | |||||||
Sun | Event | Rest | RUN | |||||
Time | 60 min | |||||||
Intensity | zone 1 | |||||||
Intensity | zone 1 | zone 2 | zone 3 | zone 4 | zone 5 | Weight training | Other sports | Total |
Low intensity | Middle intensity | High intensity | ||||||
Heart rate (%max) | 60–72 | 72–82 | 82–88 | 88–92 | 92–100 | |||
Time | 590 | 230 | 20 | 40 | 22 | 180 | 90 | 1172 |
Training as a % total volume | 50.34 | 19.62 | 1.70 | 3.41 | 1.87 | 15.35 | 7.67 | 100 |
Section | 4 | 1 | 1 | 1 | 1 | 2 | 1 | 11 |
Weight event | 65%(1RM) × 15rd × 3 set, recovery time 90 s Bench press (put legs on the bench, not on the floor) & pull-down Triceps pull-downs, deadlift Rowing/arm-pull while sitting & arm-press with dumb-bells using incline bench, legs: squats & hamstring curl, single-leg squat, side squat | |||||||
Core training | Exercise 3 set, recovery 60 s Supine plank, prone plank, side plank, side plank-leg motions statically, spine in a neutral position, Swiss ball training(inclined press-ups, top position, single-leg holds, quadruped motions) |
Variables | Male | Female | ||||
---|---|---|---|---|---|---|
Pre | Post | p-Value | Pre | Post | p-Value | |
Weight (kg) | 72.2 ± 5.19 | 68.8 ± 4.08 | 0.079 | 57.3 ± 5.96 | 51.1 ± 3.90 | 0.120 |
BMI (kg/m2) | 24.6 ± 2.10 | 23.4 ± 1.10 | 0.058 | 21.9 ± 2.71 | 19.4 ± 3.90 | 0.120 |
Muscle mass (kg) | 34.1 ± 2.68 | 32.6 ± 5.40 | 0.916 | 29.1 ± 7.7 | 29.1 ± 7.7 | 0.263 |
Body fat (%) | 18.1 ± 7.12 | 12.7 ± 2.74 | 0.028 * | 25.2 ± 4.3 | 21.4 ± 4.2 | 0.013 * |
VO2max (L min−1) | 4.95 ± 0.39 | 5.17 ± 0.14 | 0.069 | 3.16 ± 0.39 | 3.28 ± 0.16 | 0.069 |
VO2max (mL/min−1/kg−1) | 71.05 ± 7.90 | 77.0 ± 4.49 | 0.327 | 60.26 ± 4.20 | 64.33 ± 3.29 | 0.233 |
HRmax (beat/min) | 192 ± 9 | 192 ± 6 | 0.833 | 192 ± 9 | 193 ± 11 | 0.612 |
AT (L/min) | 3.02 ± 0.84 | 3.29 ± 0.90 | 0.499 | 2.18 ± 0.35 | 2.28 ± 0.21 | 0.575 |
ATHR (beat/min) | 155 ± 20 | 155 ± 15 | 0.735 | 165 ± 9 | 170 ± 11.72 | 0.121 |
All-out time (s) | 1038 ± 46.1 | 1064 ± 49.6 | 0.161 | 855.2 ± 53.4 | 874.75 ± 52.6 | 0.120 |
Recovery time (s) | 168.8 ± 56.1 | 102.6 ± 22.9 | 0.036 * | 138 ± 48.8 | 129.6 ± 56.0 | 0.327 |
Ski ergometer | ||||||
1 set time (s) | 122.5 ± 6.5 | 117 ± 2.4 | 0.028 * | 149.3 ± 20.8 | 142.6 ± 8.36 | 0.263 |
2 set time (s) | 123.4 ± 8.7 | 121.9 ± 9.5 | 0.400 | 155.3 ± 13.1 | 144.7 ± 8.71 | 0.021 * |
3 set time (s) | 126.1 ± 7.0 | 123.6 ± 8.9 | 0.233 | 150.3 ± 9.73 | 144.7 ± 8.46 | 0.021 * |
Variables | Group | Pre | Post | F | p-Value |
---|---|---|---|---|---|
Weight (kg) | Male | 72.2 ± 5.19 | 68.8 ± 4.08 | 17.159 | 0.003 * |
Female | 57.3 ± 5.96 | 51.1 ± 3.90 | |||
BMI (kg/m2) | Male | 24.6 ± 2.10 | 23.4 ± 1.10 | 26.487 | <0.001 * |
Female | 21.9 ± 2.71 | 19.4 ± 3.90 | |||
Muscle mass (kg) | Male | 34.1 ± 2.68 | 32.6 ± 5.40 | 0.456 | 0.511 |
Female | 29.1 ± 7.7 | 29.1 ± 7.7 | |||
Body fat (%) | Male | 18.1 ± 7.12 | 12.7 ± 2.74 | 12.537 | 0.004 * |
Female | 25.2 ± 4.3 | 21.4 ± 4.2 | |||
VO2 (mL/kg/min) | Male | 4.95 ± 0.39 | 5.17 ± 0.14 | 71.925 | <0.001 * |
Female | 3.16 ± 0.39 | 3.28 ± 0.16 | |||
VO2max (mL/kg/min) | Male | 71.05 ± 7.90 | 77.0 ± 4.49 | 17.718 | <0.001 * |
Female | 60.26 ± 4.20 | 64.33 ± 3.29 | |||
HRmax (beat/min) | Male | 192 ± 9 | 192 ± 6 | 0.157 | 0.698 |
Female | 192 ± 9 | 193 ± 11 | |||
AT (L/min) | Male | 3.02 ± 0.84 | 3.29 ± 0.90 | 4.382 | 0.028 * |
Female | 2.18 ± 0.35 | 2.28 ± 0.21 | |||
ATHR (beat/min) | Male | 155 ± 20 | 155 ± 15 | 2.987 | 0.108 |
Female | 165 ± 9 | 170 ± 11 | |||
All-out time (sec) | Male | 1038 ± 46.1 | 1064 ± 49.6 | 1.427 | 0.254 |
Female | 855.2 ± 53.4 | 874.75 ± 52.6 | |||
Recovery time (sec) | Male | 168.8 ± 56.1 | 102.6 ± 22.9 | 1.630 | 0.224 |
Female | 138 ± 48.8 | 129.6 ± 56.0 |
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Kim, T.H.; Han, J.K.; Lee, J.Y.; Choi, Y.C. The Effect of Polarized Training on the Athletic Performance of Male and Female Cross-Country Skiers during the General Preparation Period. Healthcare 2021, 9, 851. https://doi.org/10.3390/healthcare9070851
Kim TH, Han JK, Lee JY, Choi YC. The Effect of Polarized Training on the Athletic Performance of Male and Female Cross-Country Skiers during the General Preparation Period. Healthcare. 2021; 9(7):851. https://doi.org/10.3390/healthcare9070851
Chicago/Turabian StyleKim, Tae Ho, Joung Kyue Han, Ji Young Lee, and Yong Chul Choi. 2021. "The Effect of Polarized Training on the Athletic Performance of Male and Female Cross-Country Skiers during the General Preparation Period" Healthcare 9, no. 7: 851. https://doi.org/10.3390/healthcare9070851