|If you want to keep up with the latest science from exercise research labs around the world, today's installment of the SuppVersity Short News is for you!|
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- Strength training improves performance and pedaling characteristics in elite cyclists (Habets. 2015) - The purpose of the latest study from the Lillehammer University College was to investigate the effect of 25 weeks heavy strength training in young elite cyclists.
Nine cyclists performed endurance training and heavy strength training (ES) while seven cyclists performed endurance training only (E). ES, but not E, resulted in increases in isometric half squat performance, lean lower body mass, peak power output during Wingate test, peak aerobic power output (Wmax), power output at 4 mmol/L lactate concentrations, mean power output during 40-min all-out trial, and earlier occurrence of peak torque during the pedal stroke (P < 0.05).
Figure 1: Pre- vs. post changes (%) in relevant performance markers (Habets. 2015)
In conclusion, heavy strength training leads to improved cycling performance in elite cyclists as evidenced by a superior effect size of ES training vs E training on relative improvements in power output at 4 mmol L lactacte levels and peak power output during 30-s Wingate test, Wmax, and mean power output during 40-min all-out trial.
- Controlled-frequency breath swimming improves swimming performance and running economy (Lavin. 2015) - Respiratory muscle fatigue can negatively impact athletic performance, but swimming has beneficial effects on the respiratory system and may reduce susceptibility to fatigue. Limiting breath frequency during swimming further stresses the respiratory system through hypercapnia and mechanical loading and may lead to appreciable improvements in respiratory muscle strength. The latest study from the Human Performance Laboratory at the Ball State University assessed the effects of controlled-frequency breath (CFB) swimming on pulmonary function.
Figure 2: Sign. intergroup differences were observed for the total and rel. number of breaths (Lavin. 2015).
Post-training, maximum expiratory pressure improved by 11% (15) for all 18 subjects (P < 0.05) while maximum inspiratory pressure was unchanged. Running economy improved by 6 (9)% in CFB following training (P < 0.05). Forced vital capacity increased by 4% (4) in SM (P < 0.05) and was unchanged in CFB. As the scientists point out, "[t]hese findings suggest that limiting breath frequency during swimming may improve muscular oxygen utilization during terrestrial exercise in novice swimmers" (Lavin. 2015).
- Changes in peak fat oxidation in response to different doses of endurance training (Rosenkilde. 2015) - The latest study from the University of Copenhagen probed the effects of different doses of endurance training on the capacity to oxidize fat during exercise in sedentary, overweight men and assessed the association of these variables with changes in peak fat oxidation (PFO).
Young, sedentary, overweight men were randomized to either the high-dose (HIGH, 600 kcal/day, n = 17) or moderate-dose (MOD, 300 kcal/day, n = 18) endurance training groups or controls (CON, n = 15). PFO and peak oxygen uptake (VO2 peak) were measured using indirect calorimetry, body composition using dual-energy x-ray absorptiometry, and protein levels of mitochondrial enzymes determined by Western blotting.
The scientists conclude that the peak fatty acid oxidation (PFO) during exercise increased with both moderate- and high-dose endurance training. In that, the increases in PFO were mainly predicted by changes in VO2 peak, FFM, and cycling efficiency, and less with skeletal muscle mitochondrial enzymes.
- Can parallel use of different running shoes decrease running-related injury risk? (Malisoux. 2015) - The aim of the latest study from the Public Research Centre for Healt in Luxembourg was to determine if runners who use concomitantly different pairs of running shoes are at a lower risk of running-related injury (RRI).
Recreational runners (n = 264) participated in this 22-week prospective follow-up and reported all information about their running session characteristics, other sport participation and injuries on a dedicated Internet platform. A RRI was defined as a physical pain or complaint located at the lower limbs or lower back region, sustained during or as a result of running practice and impeding planned running activity for at least 1 day.
Figure 4: Relative (%) reduction in hazard ratio for injury risk (Malisoux. 2015)
Multiple shoe use and participation in other sports are strategies potentially leading to a variation of the load applied to the musculoskeletal system. They could be advised to recreational runners to prevent RRI.
- Half-time re-warm up increases performance capacity in male elite soccer players (Edholm. 2015) - The latest study from the Örebro University investigated the acute effects of a half-time re-warm up on performance and movement patterns in soccer match play. Using a crossover design, 22 professional male players performed traditional passive rest (CON) or a low-intensity re-warm up (RW) during the half-time period of two soccer matches. Before and after the first half and before the second half, maximal sprint and jump performance were evaluated. Time–motion analysis of the first 15 min of each half was conducted.
- The effect of high-intensity training on mitochondrial fat oxidation in skeletal muscle and subcutaneous adipose tissue (Larsen. 2015) - High-intensity interval training (HIT) is known to increase mitochondrial content in a similar way as endurance training [60–90% of maximal oxygen uptake (VO2peak)]. Whether HIT increases the mitochondria's ability to oxidize lipids is currently debated.
HIT significantly increased VO2peak from 2.9 ± 0.2 to 3.1 ± 0.2 L/min. No differences were seen in maximal fat oxidation in either skeletal muscle or adipose tissue. Kmapp for octanoyl carnitine or palmitoyl carnitine were similar after training in skeletal muscle and adipose tissue.
Maximal OXPHOS capacity with complex I- and II-linked substrates was increased after training in skeletal muscle but not in adipose tissue. The scientists conclude: "6 weeks of HIT increased VO2peak. Mitochondrial content and mitochondrial OXPHOS capacity were increased in skeletal muscle, but not in adipose tissue. Furthermore, mitochondrial fat oxidation was not improved in either skeletal muscle or adipose tissue" (Larsen. 2015).
- Edholm, P., Krustrup, P. and Randers, M. B. (2015), Half-time re-warm up increases performance capacity in male elite soccer players. Scandinavian Journal of Medicine & Science in Sports, 25: e40–e49. doi: 10.1111/sms.12236
- Habets, B. and van Cingel, R. E. H. (2015), Eccentric exercise training in chronic mid-portion Achilles tendinopathy: A systematic review on different protocols. Scandinavian Journal of Medicine & Science in Sports, 25: 3–15. doi: 10.1111/sms.12208.
- Larsen, S., Danielsen, J. H., Søndergård, S. D., Søgaard, D., Vigelsoe, A., Dybboe, R., Skaaby, S., Dela, F. and Helge, J. W. (2015), The effect of high-intensity training on mitochondrial fat oxidation in skeletal muscle and subcutaneous adipose tissue. Scandinavian Journal of Medicine & Science in Sports, 25: e59–e69. doi: 10.1111/sms.12252
- Lavin, K. M., Guenette, J. A., Smoliga, J. M. and Zavorsky, G. S. (2015), Controlled-frequency breath swimming improves swimming performance and running economy. Scandinavian Journal of Medicine & Science in Sports, 25: 16–24. doi: 10.1111/sms.12140.
- Malisoux, L., Ramesh, J., Mann, R., Seil, R., Urhausen, A. and Theisen, D. (2015), Can parallel use of different running shoes decrease running-related injury risk?. Scandinavian Journal of Medicine & Science in Sports, 25: 110–115. doi: 10.1111/sms.12154.
- Rosenkilde, M., Reichkendler, M. H., Auerbach, P., Bonne, T. C., Sjödin, A., Ploug, T. and Stallknecht, B. M. (2015), Changes in peak fat oxidation in response to different doses of endurance training. Scandinavian Journal of Medicine & Science in Sports, 25: 41–52. doi: 10.1111/sms.12151