Argyro Krase

Rate of Force Development, Muscle Architecture, and Performance in Young Competitive Track and Field Throwers.

Abstract Zaras, ND, Stasinaki, A-NE, Methenitis, SK, Krase, AA, Karampatsos, GP, Georgiadis, GV, Spengos, KM, and Terzis, GD. Rate of force development, muscle architecture, and performance in young competitive track and field throwers. J Strength Cond Res 30(1): 81–92, 2016—The rate of force development (RFD) is an essential component for performance in explosive activities, although it has been proposed that muscle architectural characteristics might be linked with RFD and power performance. The purpose of the study was to investigate the relationship between RFD, muscle architecture, and performance in young track and field throwers. Twelve young track and field throwers completed 10 weeks of periodized training. Before (T1) and after (T2) training performance was evaluated in competitive track and field throws, commonly used shot put tests, isometric leg press RFD, 1 repetition maximum (1RM) strength as well as vastus lateralis architecture and body composition. Performance in competitive track and field throwing and the shot put test from the power position increased by 6.76 ± 4.31% (p < 0.001) and 3.58 ± 4.97% (p = 0.019), respectively. Rate of force development and 1RM strength also increased (p ⩽ 0.05). Vastus lateralis thickness and fascicle length increased by 5.95 ± 7.13% (p = 0.012) and 13.41 ± 16.15% (p = 0.016), respectively. Significant correlations were found at T1 and T2, between performance in the shot put tests and both RFD and fascicle length (p ⩽ 0.05). Close correlations were found between RFD, muscle thickness, and fascicle length (p ⩽ 0.05). Significant correlations were found between the % changes in lean body mass and the % increases in RFD. When calculated together, the % increase in muscle thickness and RFD could predict the % increase in shot put throw test from the power position (p = 0.019). These results suggest that leg press RFD may predict performance in shot put tests that are commonly used by track and field throwers.

Effects of Tapering With Light vs. Heavy Loads on Track and Field Throwing Performance

Abstract Zaras, ND, Stasinaki, A-NE, Krase, AA, Methenitis, SK, Karampatsos, GP, Georgiadis, GV, Spengos, KM, and Terzis, GD. Effects of tapering with light vs. heavy loads on track and field throwing performance. J Strength Cond Res 28(12): 3484–3495, 2014—The purpose of the study was to investigate the effects of power training with light vs. heavy loads during the tapering phases of a double periodized training year on track and field throwing performance. Thirteen track and field throwers aged 16–26 years followed 8 months of systematic training for performance enhancement aiming at 2 tapering phases during the winter and the spring competition periods. Athletes performed tapering with 2 different resistance training loads (counterbalanced design): 7 athletes used 30% of 1 repetition maximum (1RM) light-load tapering (LT), and 6 athletes used the 85% of 1RM heavy-load tapering (HT), during the winter tapering. The opposite was performed at the spring tapering. Before and after each tapering, throwing performance, 1RM strength, vertical jumping, rate of force development (RFD), vastus lateralis architecture, and rate of perceived exertion were evaluated. Throwing performance increased significantly by 4.8 ± 1.0% and 5.6 ± 0.9% after LT and HT, respectively. Leg press 1RM and squat jump power increased more after HT than LT (5.9 ± 3.2% vs. −3.4 ± 2.5%, and 5.1 ± 2.4% vs. 0.9 ± 1.4%, respectively, p ⩽ 0.05). Leg press RFD increased more in HT (38.1 ± 16.5%) compared with LT (−2.9 ± 6.7%), but LT induced less fatigue than HT (4.0 ± 1.5 vs. 6.7 ± 0.9, p ⩽ 0.05). Muscle architecture was not altered after either program. These results suggest that performance increases similarly after tapering with LT or HT in track and field throwers, but HT leads to greater increases in strength, whole body power, and RFD.

Effects of exercise training during infusion on late-onset Pompe disease patients receiving enzyme replacement therapy

Pompe disease is an autosomal recessive disorder caused by the deficiency of acid α-glucosidase resulting in lysosomal accumulation of glycogen and abnormal autophagic function. The late-onset form of the disease is characterized by progressive skeletal and respiratory muscle dysfunction. Enzyme replacement therapy (ERT, Genzyme Corporation, Cambridge, MA, USA) was recently introduced and resulted in significant prolongation of the life expectancy of the patients with the infantile form while the results were less significant for the late-onset form. It has been postulated that the weak influence of ERT in late-onset patients might be due to a non-effective delivery of the recombinant enzyme to the skeletal muscles perhaps due to the relatively low blood flow to the resting skeletal muscles during infusion. Exercise training acutely increases the blood flow to the exercising muscles. Thus, it was hypothesized that exercise training during enzyme infusion might increase the effectiveness of the ERT therapy. Five late-onset Pompe disease patients receiving ERT and following regular exercise training for approximately 10 months, followed a 6-month period of exercise training during infusion of the recombinant enzyme. Before and after this period, body composition, isometric strength and 6 minute walking distance were determined. Analysis of the results revealed that none of these parameters changed significantly after the 6-month intervention period (e.g. 6 minute walking distance before: 532±31 m, vs. after: 527±29 m, P=0.246). These results suggest that exercise training during infusion may not add significant functional changes in late-onset Pompe patients receiving ERT and undergoing regular exercise training.

Functional capacity in a late-onset Pompe disease patient: Effect of enzyme replacement therapy and exercise training

Annals of Indian Academy of Neurology, July-September 2016, Vol 19, Issue 3 exercise training frequency and intensity returned to the previous level. The higher FVC was attained with the combination of ERT and exercise training. The current data suggest that the combination of moderate intensity resistance and aerobic exercise may sustain functional capacity and muscle strength in ambulatory LOPD patients after voluntary withdrawal from of ERT. Exercise training should be of moderate intensity to avoid possible detrimental effects of excessive loading, especially in patients with cardiac involvement along with myopathy.