Impact of Inertial Training on Strength and Power Performance in Young Active Men.

Naczk, M, Naczk, A, Brzenczek-Owczarzak, W, Arlet, J, and Adach, Z. Impact of inertial training on strength and power performance in young active men. J Strength Cond Res 30(8): 2107-2113, 2016-This study evaluated how 5 weeks of inertial training using 2 different loads influenced strength and power performance. Fifty-eight male physical education students were randomly divided into training and control groups. The 2 training groups (T0 and T10) performed inertial training 3 times per week for 5 weeks using the new Inertial Training and Measurement System (ITMS). Each training session included 3 exercise sets involving the knee extensors muscles. The T0 group used only the mass of the ITMS flywheel (19.4 kg), whereas the T10 group had an additional 10 kg on the flywheel. Before and after training, we evaluated maximum force and power of knee extensors muscles, countermovement jump (CMJ), squat jump (SJ), maximal power output achieved during ergometer test PVT, electromyography of quadriceps, and muscle mass. In T0 and T10, respectively, ITMS training induced significant increases in muscle force (25.2 and 23.3%), muscle power (33.2 and 27%), CMJ (3.8 and 6.7%), SJ (2.2 and 6.1%), PVT (8 and 7.4%), and muscle mass (9.8 and 15%). The changes did not significantly differ between T0 and T10. A 16% significant increase of electromyography amplitude (quadriceps muscle) was noted only in T0. The novel ITMS training method is effective for improving muscular strength and power. Improvements in PVT, CMJ, and SJ indicate that the increased strength and power elicited by ITMS training can translate to improvements in sport performance. The ITMS training can also be useful for building muscle mass.

The impact of inertial exercises performed in the workplace on shoulder muscles' strength and muscles' fatigue resistance in women with disabilities.

BACKGROUND: Workers who do monotonous and repetitive work in a static position often complain about fatigue and decreased work efficiency. Some studies indicate that to improve muscle fatigue, resistance strength training can be used. MATERIAL AND METHODS: To investigate the effect of 4-week inertial training on shoulder muscles' strength and muscles' fatigue resistance 44 female workers with disabilities were examined. The participants were randomized into the training group (T) (N = 32) and the control group (C) (N = 12). Before the training and after that shoulder muscles' strength were tested at the start and at the end of the workday (Monday and Friday). The participants were asked to complete questionnaire concerning their fatigue at work (T and C), inertial training and work efficiency (T). RESULTS: The work performed during the last day of the workweek, i.e., Friday (before training) resulted in a significant decrease in shoulder muscles' strength in T and C. Muscle strength achieved at the end of the workweek (Friday afternoon) was significantly lower than achieved at the start of the workweek (Monday morning) in both tested groups (before training). Moreover, inertial training resulted in a significant increase in shoulder muscles' strength in T; 34-74% for different muscles. No changes in muscles' strength were noted in C. Increased muscle strength in T following inertial training effectively prevented muscle fatigue. After training the differences in shoulder muscles' strength noted in T during different times of the workday and workweek were insignificant. Moreover, 4-week inertial training increased significantly the work efficiency of women from T by 4%; no changes were noted in C. Inertial training was well tolerated by the participants. CONCLUSIONS: Using inertial training in women with disabilities to prevent shoulder muscles' fatigue during the workday and workweek is recommended. Med Pr Work Health Saf. 2024;75(2):113-122.

Estimation of the efficacy of inertial training in older women.

This study aimed to estimate the efficacy of inertial training in older women using the Inertial Training and Measurement System (ITMS), an original device. Forty-five active women age 53-74 yr performed inertial training with 2 different loads (0 or 5 kg) 3 times weekly for 4 wk. Training sessions consisted of exercises involving the shoulder muscles of the dominant and nondominant arms. The maximal torque and power developed by the dominant and nondominant arms in the 0-kg and 5-kg groups were significantly greater after 4 wk of inertial training (with the exception of torque for the nondominant arm in the 5-kg group; p > .05). Thus, short-term training using the ITMS is efficacious and can be used in older women to improve strength and power. However, ITMS training-induced changes in older women are greater after application of smaller external loads.

Influence of short-term inertial training on swimming performance in young swimmers.

The aim of this study was to evaluate the influence of dry-land inertial training (IT) on muscle force, muscle power, and swimming performance. Fourteen young, national-level, competitive swimmers were randomly divided into IT and control (C) groups. The experiment lasted four weeks, during which time both groups underwent their regular swimming training. In addition, the IT group underwent IT using the Inertial Training Measurement System (ITMS) three times per week. The muscle groups involved during the upsweep phase of the arm stroke in front crawl and butterfly stroke were trained. Before and after training, muscle force and power were measured under IT conditions. Simultaneously with the biomechanical measurements on the ITMS, the electrical activity of the triceps brachii was registered. After four weeks of training, a 12.8% increase in the muscle force and 14.2% increase in the muscle power (p < .05) were noted in the IT group. Moreover, electromyography amplitude of triceps brachii recorded during strength measurements increased by 22.7% in the IT group. Moreover, swimming velocity in the 100 m butterfly and 50 m freestyle improved significantly following the four weeks of dry-land IT (-1.86% and -0.76%, respectively). Changes in the C group were trivial. Moreover, values of force and power registered during the ITMS test correlated negatively with the 100 m butterfly and 50 m freestyle swimming times (r value ranged from -.80 to -.91). These results suggest that IT can be useful in swimming practice.

EMG and MMG of agonist and antagonist muscles as a function of age and joint angle.

The aim of this study was to determine the effect of elbow joint position on electromyographic (EMG) and mechanomyographic (MMG) activities of agonist and antagonist muscles in young and old women. Surface EMG and MMG were recorded from the triceps and biceps brachii, and brachioradialis muscles during isometric elbow extensions in young and old women. The measurements were carried out at an optimal joint angle (A(o)), as well as at smaller (A(s) = A(o) - 30 degrees ) and larger (A(l) = A(o) + 30 degrees ) angles. The normalized to force EMG amplitude (RMS-EMG/F) was smaller in old women compared to young in all muscles. The RMS-EMG/F of the triceps brachii muscle was not affected by muscle length while that of the biceps brachii and brachioradialis muscles increased at shortest muscle length in both groups. The normalized to force MMG amplitude (RMS-MMG/F) was smaller in old than in young in the triceps brachii muscle only. There was an increase in RMS-MMG/F with triceps brachii and biceps brachii muscle shortening in both groups, and in the brachioradialis muscle -- in young only. Compared to young, older women exhibited a bigger force fluctuation during maximum voluntary contraction, but these did not contribute significantly to the RMS-MMG. Skinfold thickness accounted for the RMS-EMG/F and RMS-MMG/F differences seen between old and young women in the biceps brachii muscle only. It is concluded that, the EMG and MMG response to muscles length change in agonist and antagonist muscles is generally similar in old and young women but the optimal angle shifts toward a bigger value in older women.

Efficacy of inertial training in elbow joint muscles: influence of different movement velocities.

BACKGROUND: The aim of this study was to evaluate the influence of inertial training performed with different movement velocities on elbow flexor and extensor strength and power. METHODS: Thirty-eight male physical education students were divided into training and control groups. The two training groups performed inertial training three times per week for five weeks using the Inertial Training Measurement System. Elbow joint flexors and extensors were trained using different maximal movement velocities: 7.50 rad·s(-1) in the faster (TF) group and 5.76 rad·s(-1) in the slower (TS) group. Before and after training, we evaluated maximum force and power of elbow flexors and extensors muscles under training conditions, maximum torque and power of elbow flexors and extensors muscles under isokinetic conditions and maximal power output achieved during upper body Ergometer Test. RESULTS: Training induced significant increases in elbow flexor force (28.4% in TF and 13.7% in TS) and power (37.7% in TF and 12.4% in TS) measured under training conditions. However, changes in the elbow flexors in the TF group were greater than in the TS group. Elbow extensor force and power measured under inertial conditions increased significantly only in the TF group; 12.5% and 21.1%, respectively. Moreover, the EMG amplitude of the biceps brachii and triceps brachii and upper limb muscle mass increased in both training groups. Measurements made under isokinetic conditions indicated that torque and power improved only in the elbow flexors, no changes in maximal power output were observed during the upper limb Ergometer Test. CONCLUSIONS: The short-term inertial training resulted in significant elbow muscles strength and power improvements. ITMS training induced also the increase of upper limbs muscle mass and the increase of EMG activity of muscles during flexion and extension of elbow. Moreover, greater movement velocities seem to be a benefit for strength and power enhancement. However, further studies are needed to confirm this suggestion.

Training effectiveness of the inertial training and measurement system.

The purpose of this study was to evaluate the efficacy of inertial training with different external loads using a new original device - the Inertial Training and Measurement System (ITMS). Forty-six physical education male students were tested. The participants were randomly divided into three training groups and a control group (C group). The training groups performed inertial training with three different loads three times weekly for four weeks. The T0 group used only the mass of the ITMS flywheel (19.4 kg), the T5 and T10 groups had an additional 5 and 10 kg on the flywheel, respectively. Each training session included three exercise sets involving the shoulder joint adductors. Before and after training, the maximal torque and power were measured on an isokinetic dynamometer during adduction of the shoulder joint. Simultaneously, the electromyography activity of the pectoralis major muscle was recorded. Results of the study indicate that ITMS training induced a significant increase in maximal muscle torque in the T0, T5, T10 groups (15.5%, 13.0%, and 14.0%, respectively). Moreover, ITMS training caused a significant increase in power in the T0, T5, T10 groups (16.6%, 19.5%, and 14.5%, respectively). The percentage changes in torque and power did not significantly differ between training groups. Electromyography activity of the pectoralis major muscle increased only in the T0 group after four weeks of training. Using the ITMS device in specific workouts allowed for an increase of shoulder joint adductors torque and power in physical education students.