Vasilios I. Kalapotharakos

Effects of a Heavy and a Moderate Resistance Training on Functional Performance in Older Adults

Resistance training can improve strength and functional performance, but there is little information about the effect of training intensity on functional performance in older adults. The purpose of this study was to determine the effect of 12 weeks of heavy (80% of 1 repetition maximum [1RM]) and moderate (60% of 1RM) resistance training on functional performance in healthy, inactive older adults, ages 60–74 years. Volunteer subjects were assigned randomly to a control group (CS, n = 10), heavy resistance training group (HRT, n = 11), or moderate resistance training group (MRT, n = 12) and participated in 12 weeks of strength training, 3 times per week. Performance measurements included 1RM lower-body strength, chair-rising time, walking velocity, stair-climbing time, and flexibility. Significant differences between HRT and MRT were found for 1RM strength of the lower limbs after the training period. Functional performance improved similarly for both HRT and MRT after the training period. Functional performance can be improved significantly with either heavy or moderate resistance training, without significant differences in the effectiveness of the 2 training protocols.

Seasonal Aerobic Performance Variations in Elite Soccer Players

Kalapotharakos, VI, Ziogas, G, and Tokmakidis, SP. Seasonal aerobic performance variations in elite soccer players. J Strength Cond Res 25(6): 1502-1507, 2011—The purpose of this study was to examine the seasonal changes in body composition and aerobic performance in elite soccer players. Twelve elite professional soccer players (aged 25 ± 5 years, weight 75.7 ± 5.3 kg, height 1.79 ± 0.06 m) were measured for body fat (%), maximum oxygen consumption (&OV0312;o2max), running velocity at &OV0312;o2max (v&OV0312;o2max), running velocity at a fixed blood lactate concentration of 4 mmol·L−1 (v-4 mM) at the start of the preseason period, at the beginning of the competitive period, and at midseason. &OV0312;o2max, v-4 mM, and v&OV0312;o2max increased significantly (p < 0.05) by 4.5, 10.5, and 7.8, respectively, after the preseason period. Thereafter, the aerobic performance parameters remained relatively constant, with no significant changes throughout the competitive period. The results of this study suggest that moderate improvements were observed in &OV0312;o2max, and the %&OV0312;o2max at 4 v-4 mM, whereas higher improvements were observed in v&OV0312;o2max and v-4 mmol·L−1 after the preseason training period. On the other hand, during the competitive period, aerobic performance remained unchanged. In addition, this study suggests that heart rate, lactate, &OV0312;o2, and v&OV0312;o2max are useful and practical predictors that help monitor aerobic performance changes during a soccer season.

The effect of moderate resistance strength training and detraining on muscle strength and power in older men.

Purpose: The purpose of the present study was to evaluate the effects of 10 weeks of moderate resistance strength training followed by 6 weeks of detraining on muscle strength and jump performance in healthy, moderately active, older men, aged 61 ‐ 75 years (mean age 68 ± 5 years). Methods: Subjects were randomly assigned to a moderate resistance strength training group (RT, n=9), or to a control group (C, n=9). The RT group trained upper and lower body muscle groups at 60% of 1‐Repetition Maximum (1‐RM), 3 times per week for 12 weeks. Both groups were evaluated in the 1‐RM knee extension and flexion strength, squat jump (SJ), and countermovement jump (CMJ) height before and after the training period. In addition, the RT group was evaluated in the same measurements after 6 weeks of detraining. Results: After the training period, RT improved significantly (p < 0.001) the 1‐RM knee extension (32%) and flexion (28%) strength, SJ (39%), and CMJ (31%) height. Significant reductions were observed in 1‐RM lower body strength, SJ, and CMJ height by approximately 15%, after the detraining period. Conclusions: Muscle strength and vertical jump performance improved after short‐term moderate resistance strength training. A short‐term detraining period affects the muscle strength and power in older adults, but the neuromuscular function does not return to pretraining levels. This suggests that the continuation of a strength training program is essential for the maintenance of muscle strength, functional performance, and independence in older adults.

Effects of detraining on muscle strength and mass after high or moderate intensity of resistance training in older adults.

This study examined the effects of a 12 weeks detraining period on muscle strength and mass in older adults who had previously participated in a 12 weeks resistance training programme of high [80% of one repetition maximum (1‐RM)] or moderate (60% of 1‐RM) intensity. Twenty older adults (60–74 years), separated into a high (HI; n = 10; age: 65 ± 5 years) and a moderate (MI; n = 10; age: 66 ± 4 years) intensity resistance training group, were measured in the 1‐RM knee extension and flexion strength, and the midthigh cross sectional areas (CSAs) of quadriceps, hamstrings and total thigh before and after a 12 weeks training period as well as after a 12 weeks detraining period. Maximum knee extension and flexion strength and the CSAs of all muscles decreased significantly (P<0·05) with detraining but remained higher (P<0·05) than pretraining levels for both groups. The HI group had a greater decrement (P<0·05) in maximum strength and the CSA of total thigh compared to the MI group but strength levels and the CSA following detraining were higher (P<0·05) for the HI group. The above data suggest that after a short detraining period of 12 weeks, muscle strength and hypertrophy levels of older adults decrease but remain greater than pretraining irrespective of training intensity. Greater declines in muscle strength are observed following HI training but still muscular strength and muscle mass are retained at a higher level than with MI probably due to the higher gains achieved during the training period.

Effects of resistance training and detraining on muscle strength and functional performance of older adults aged 80 to 88 years

Background and aims: Limited data exist on the effects of resistance training and detraining on functional performance in very old adults aged >80 years. First, to determine the effects of an 8-week resistance exercise program on muscle strength and functional performance in very old men. Second, to examine the effect of a 6-week detraining period in muscle strength and functional performance. Methods: Twenty-two men, aged >80 years, were randomized to three groups: resistance exercise-detraining group (RDT; n=8), resistance exercise group (RT; n=7) and control group (CON; n=7). RT and RDT groups performed an 8 week resistance exercise program for lower and upper muscle groups, two times a week. Thereafter, RDT underwent a 6-week detraining period, whereas the RT group continued resistance exercise. 3-RM strength, 6-minute walk distance (6-MWD), chair rising time, and Timed-Up and Go (TUG) tests were assessed at baseline, and at week 8 and week 14. Results: Significant improvements were observed in 3-RM strength (25%, to 55%; p<0.001) and functional performance (15 to 25%; p<0.001 ) tests, in RDT and RT after 8 weeks of exercise. RT continued to improve muscle strength and 6-MWD significantly (p<0.05) until the end of the exercise period, whereas significant declines in muscle strength (60 to 87%; p<0.05) and functional performance (36 to 70%; p<0.05) gains occurred during the exercise period were observed in RDT during the &week detraining period. No significant differences were observed in the control group. Conclusions: Results indicate that a resistance exercise program induces favorable muscular and functional adaptations in very old adults. However, a significant part of the favorable adaptations obtained after resistance exercise may be lost within 6 weeks of detraining. Therefore, very old adults should follow a long-term and systematic routine of exercise throughout life, in order to improve and maintain their physical functions and to ameliorate their life status.

Effects of a 10-Week Resistance Exercise Program on Soccer Kick Biomechanics and Muscle Strength

Abstract Manolopoulos, E, Katis, A, Manolopoulos, K, Kalapotharakos, V, and Kellis, E. Effects of a 10-week resistance exercise program on soccer kick biomechanics and muscle strength. J Strength Cond Res 27(12): 3391–3401, 2013—The purpose of the study was to examine the effects of a resistance exercise program on soccer kick biomechanics. Twenty male amateur soccer players were divided in the experimental group (EG) and the control group (CG), each consisting of 10 players. The EG followed a 10-week resistance exercise program mainly for the lower limb muscles. Maximal instep kick kinematics, electromyography, and ground reaction forces (GRFs) as well as maximum isometric leg strength were recorded before and after training. A 2-way analysis of variance showed significantly higher ball speed values only for the EG (26.14 ± 1.17 m·s−1 vs. 27.59 ± 1.49 m·s−1 before and after training, respectively), whereas no significant differences were observed for the CG. The EG showed a decline in joint angular velocities and an increase in biceps femoris electromyography of the swinging leg during the backswing phase followed by a significant increase in segmental and joint velocities and muscle activation of the same leg during the forward swing phase (p < 0.05). The EG also showed significantly higher vertical GRFs and rectus femoris and gastrocnemius activation of the support leg (p < 0.05). Similarly, maximum and explosive isometric force significantly increased after training only for the EG (p < 0.05). These results suggest that increases in soccer kicking performance after a 10-week resistance training program were accompanied by increases in maximum strength and an altered soccer kick movement pattern, characterized by a more explosive backward-forward swinging movement and higher muscle activation during the final kicking phase.

Heart Rate Responses during Small-Sided Soccer Games

The purpose of the present study was to examine the heart rate responses during small-sided games with different number of players. Sixteen professional soccer players were evaluated for body fat (%) using the skin fold thickness at three sites, VO2 max and running velocity at the lactate threshold using an incremental treadmill protocol. %HRmax was measured during four-, five-, six-, seven-, and eight-a side soccer games. The four-a-side game showed significantly (p<0.05) higher %HRmax in comparison to the other small-sided games. On the other hand, the %HRmax of the eight-a-side game was significantly lower (p<0.05) than three-, four-, five-, six-, and seven-a-side game. The intensity of small-sided games decreases as the number of players increase. The monitoring of heart rate during small-sided games combined with laboratory VO2 max tests is a possible way to define target training intensity zones.