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Abstract: Shaw, MP, Andersen, V, Sæterbakken, AH, Paulsen, G, Samnøy, LE, and Solstad, TEJ. Contemporary training practices of Norwegian powerlifters. J Strength Cond Res 36(9): 2544-2551, 2022-The aim of this study was to explore the contemporary training practices of Norwegian powerlifters. One hundred twenty-four Norwegian powerlifters completed an electronic questionnaire that surveyed their current training practices with a focus on 2 areas: (a) training content and (b) training design and monitoring. One hundred seventeen respondents met the inclusion criteria, and the sample included World, European, and Norwegian champions. Where data were dichotomized, chi-square tests were used. The most frequently reported (58.1%) category of training was 5-6 times per week, with no statistically significant associations between levels of competitors (international vs. noninternational) (X 2 (1) = 0.414, p = 0.52). The most frequently reported load used in training was 71-80% 1 repetition maximum. The majority of Norwegian (76.9%) powerlifters train with variable resistance, with those competing internationally more likely to use elastic bands (X 2 (1) = 4.473, p = 0.034). 32.5% of respondents reported that they included strength training exercises in their training. Norwegian powerlifters' training differs from practices previously identified in the literature, with a higher prevalence of elastic resistance, particularly for those competing internationally, and a decreased use of strength training exercises at all levels. Norwegian powerlifters train frequently (5 or more times per week) and with submaximal loads., (Copyright © 2020 National Strength and Conditioning Association.)

Abstract: Saeterbakken, AH, Stien, N, Pedersen, H, and Andersen, V. Core muscle activation in three lower extremity exercises with different stability requirements. J Strength Cond Res 36(2): 304-309, 2022-The aim of the study was to compare core muscle surface electromyography (sEMG) during 3-repetition maximum (3RM) and the sEMG amplitude in the turnover from the descending to ascending phase in leg press, free-weight squats, and squats using the Smith machine. Nineteen women with 4.5 (±2.0) years of resistance training were recruited. After one familiarization session, the subjects performed 3RM in randomized order measuring electromyographic activity in the rectus abdominis, external oblique, and erector spinae. The exercises with the lowest stability requirements (leg press) demonstrated 17-59% and 17-42% lower core muscle sEMG amplitude than free weights and the Smith machine, respectively. No statistically significant differences were observed between the Smith machine and free weights. No statistically significant differences in turnover sEMG amplitude in the rectus abdominis between the exercises was observed, but lower sEMG amplitude was observed in external oblique and erector spinae in leg press compared with the other exercises. The 3RM loads in leg press were 54 and 47% greater than squats using the Smith machine and free weights, with 5% greater loads with the Smith machine than with free weights. In conclusion, lower mean and turnover core muscle sEMG amplitude were observed with the leg press but greater 3RM loads compared with squats with the Smith machine and free weights. The authors recommend that resistance-trained individuals use squats to include the core muscles in the kinetic chain, but there is no evidence that greater stability requirements (free weights instead of the Smith machine) will result in greater core muscle sEMG amplitude., (Copyright © 2020 National Strength and Conditioning Association.)

Andersen, V, Fimland, MS, Mo, D-A, Iversen, VM, Vederhus, T, Rockland Hellebø, LR, Nordaune, KI, and Saeterbakken, AH. Electromyographic comparison of barbell deadlift, hex bar deadlift, and hip thrust exercises: a cross-over study. J Strength Cond Res 32(3): 587-593, 2018-The aim of the study was to compare the muscle activation level of the gluteus maximus, biceps femoris, and erector spinae in the hip thrust, barbell deadlift, and hex bar deadlift; each of which are compound resisted hip extension exercises. After 2 familiarization sessions, 13 resistance-trained men performed a 1 repetition maximum in all 3 exercises in 1 session, in randomized and counterbalanced order. The whole ascending movement (concentric phase), as well as its lower and upper parts (whole movement divided in 2), were analyzed. The hip thrust induced greater activation of the gluteus maximus compared with the hex bar deadlift in the whole (16%, p = 0.025) and the upper part (26%, p = 0.015) of the movement. For the whole movement, the biceps femoris was more activated during barbell deadlift compared with both the hex bar deadlift (28%, p < 0.001) and hip thrust (20%, p = 0.005). In the lower part of the movement, the biceps femoris activation was, respectively, 48% and 26% higher for the barbell deadlift (p < 0.001) and hex bar deadlift (p = 0.049) compared with hip thrust. Biceps femoris activation in the upper part of the movement was 39% higher for the barbell deadlift compared with the hex bar deadlift (p = 0.001) and 34% higher for the hip thrust compared with the hex bar deadlift (p = 0.002). No differences were displayed for the erector spinae activation (p = 0.312-0.859). In conclusion, the barbell deadlift was clearly superior in activating the biceps femoris compared with the hex bar deadlift and hip thrust, whereas the hip thrust provided the highest gluteus maximus activation.

The aim of the study was to compare the electromyographic activity of rectus abdominis, oblique external, and lower and upper erector spinae at both sides of the truncus in 1-armed and 2-armed kettlebell swing. Sixteen healthy men performed 10 repetitions of both exercises using a 16-kg kettlebell in randomized order. For the upper erector spinae, the activation of the contralateral side during 1-armed swing was 24% greater than that of the ipsilateral side during 1-armed swing (p < 0.001) and 11% greater during 2-armed swing (p = 0.026). Furthermore, the activation in 2-armed swing was 12-16% greater than for the ipsilateral side in 1-armed swing (p < 0.001). For rectus abdominis, however, 42% lower activation of the contralateral side was observed during 1-armed swing compared with ipsilateral sides during 2-armed swing (p = 0.038) and 48% compared with the ipsilateral side during 1-armed swing (p = 0.044). Comparing the different phases of the swing, most differences in the upper erector spinae were found in the lower parts of the movement, whereas for the rectus abdominis, the differences were found during the hip extension. In contrast, similar muscle activity in the lower erector spinae and external oblique between the different conditions was observed (p = 0.055-0.969). In conclusion, performing the kettlebell swing with 1 arm resulted in greater neuromuscular activity for the contralateral side of the upper erector spinae and ipsilateral side of the rectus abdominis, and lower activation of the opposite side of the respective muscles.

The purpose of the study was to compare kinematic muscle activation when performing 6 repetition maximum (6RM) squats using constant (free weights) or variable resistance (free weights + elastic bands). Twenty recreationally trained women were recruited with 4.6 ± 2.1 years of resistance training experience and a relative strength (6RM/body mass) of 1.1. After a familiarization session identifying the 6RM loads, the participants performed 6RM squats using constant and variable resistance in a randomized order. The total resistance in the variable resistance group was similar to the constant resistance in the presticking region (98%), but greater in the sticking region (105%) and the poststicking region (113%). In addition, the presticking barbell velocity was 21.0% greater using variable than constant resistance, but 22.8% lower in the poststicking region. No significant differences in muscle electromyographic activity, time occurrence, and vertical displacement between the squat modalities were observed, except for higher barbell displacement poststicking using variable resistance. It was concluded that, due to differences in total resistance in the different regions performing variable compared with constant resistance, greater barbell velocity was observed in the presticking region and lower resistance was observed in the poststicking region. However, the extra resistance in the sticking and poststicking regions during the variable resistance modality did not cause increased muscle activity. When performing squats with heavy resistance, the authors recommend using variable resistance, but we suggest increasing the percentage resistance from the elastic bands or using chains.

This study compared the effects of a variable vs. a constant lower limb resistance training program on muscle strength, muscle activation, and ballistic muscle performance at different knee angles. Thirty-two females were randomized to a constant resistance training free-weight group (FWG) or a variable resistance training group using free weights in combination with elastic bands (EBG). Two variations of the squat exercise (back squat and split) were performed 2 days per week for 10 weeks. Knee extensor maximal voluntary isometric contraction (MVC) and countermovement jump were assessed at knee angles of 60, 90, and 120° before and after the intervention. During the MVCs, muscle activation of the superficial knee extensor muscles was measured using surface electromyography. The FWG increased their MVCs at 60 and 90° (24 and 15%, respectively), whereas the EBG only increased significantly at 60° (15%). The FWG increased their jump height significantly at all angles (12-16%), whereas the EBG only improved significantly at 60 and 90° (15 and 10%, respectively). Both groups improved their 6-repetition maximum free-weight squat performance (EBG: 25% and FWG: 23%). There were no significant changes in muscle activation. In conclusion, constant and variable resistance training provided similar increases in dynamic and isometric strength, and ballistic muscle performance, albeit most consistently for the group training only with free weights.

The objective of this study was to assess the electromyographic activity of the rectus abdominis (upper and lower part) and external oblique during sit-ups performed on BOSU ball(s). Twenty-four men participated in a familiarization session, and in the next session, they performed the experimental tests in randomized order. The sit-ups were performed with 10 repetitions with body weight and with 10 repetition maximum (10RM) using elastic bands as external resistance under 4 different conditions: (a) on a stable surface, (b) with the BOSU ball under their feet (dome side down, lower-body instability), (c) BOSU ball under the low back (dome side up, upper-body instability), and (d) with BOSU balls under both feet and the low back (dual instability). The feet were not attached to the surface. We observed that with body weight, external oblique activation was decreased by upper-body instability and dual instability by 22-24% (p = 0.002-0.006), whereas the rectus abdominis was not affected by the surface. Using 10RM loads, the upper and lower rectus abdominis activities were increased by upper body and dual instability by 21-24% compared with that for a stable surface (P ≤ 0.001-0.036). Further, lower-body instability did not affect muscle activities significantly with either load for any condition. Hence, BOSU balls under the low back can increase and decrease abdominal muscle activation depending on the load, whereas placing a BOSU ball under the feet with the dome side down had little impact.

The purpose of this study was to assess the effects of adding elastic bands to free-weight squats on the neuromuscular activation of core muscles. Twenty-five resistance trained women with 4.6 ± 2.1 years of resistance training experience participated in the study. In randomized order, the participants performed 6 repetition maximum in free-weight squats, with and without elastic bands (i.e., matched relative intensity between exercises). During free-weight squats with elastic bands, some of the free weights were replaced with 2 elastic bands attached to the lowest part of the squat rack. Surface electromyography (EMG) activity was measured from the erector spinae, external oblique, and rectus abdominis, whereas a linear encoder measured the vertical displacement. The EMG activities were compared between the 2 lifting modalities for the whole repetition and separately for the eccentric, concentric, and upper and lower eccentric and concentric phases. In the upper (greatest stretch of the elastic band), middle, and lower positions in squats with elastic bands, the resistance values were approximately 117, 105, and 93% of the free weight-only trial. Similar EMG activities were observed for the 2 lifting modalities for the erector spinae (p = 0.112-0.782), external oblique (p = 0.225-0.977), and rectus abdominis (p = 0.315-0.729) in all analyzed phases. In conclusion, there were no effects on the muscle activity of trunk muscles of substituting some resistance from free weights with elastic bands in the free-weight squat.

The lat pull-down is one of the most popular compound back exercises. Still, it is a general belief that a wider grip activates the latissimus dorsi more than a narrow one, but without any broad scientific support. The aim of the study was to compare 6 repetition maximum (6RM) load and electromyographic (EMG) activity in the lat pull-down using 3 different pronated grip widths. Fifteen men performed 6RM in the lat pull-down with narrow, medium, and wide grips (1, 1.5, and 2 times the biacromial distance) in a randomized and counterbalanced order. The 6RM strengths with narrow (80.3 ± 7.2 kg) and medium grip (80 ± 7.1 kg) were higher than wide grip (77.3 ± 6.3 kg; p = 0.02). There was similar EMG activation between grip widths for latissimus, trapezius, or infraspinatus, but a tendency for biceps brachii activation to be greater for medium vs. narrow (p = 0.09), when the entire movement was analyzed. Analyzing the concentric phase separately revealed greater biceps brachii activation using the medium vs. narrow grip (p = 0.03). In the eccentric phase, there was greater activation using wide vs. narrow grip for latissimus and infraspinatus (p ≤ 0.04), and tendencies for medium greater than narrow for latissimus, and medium greater than wide for biceps (both p = 0.08), was observed. Collectively, a medium grip may have some minor advantages over small and wide grips; however, athletes and others engaged in resistance training can generally expect similar muscle activation which in turn should result in similar hypertrophy gains with a grip width that is 1-2 times the biacromial distance.

Little is known about the effect of performing upper-body resistance exercises with dumbbells versus barbells and standing versus seated. Therefore, this study sought to compare electromyogram activity (EMG) and one-repetition maximum (1-RM) in barbell and dumbbell shoulder presses performed seated and standing. Fifteen healthy men volunteered for 1-RM and EMG testing with a load corresponding to 80% of the 1-RM. Electromyogram activity was measured in the anterior, medial, and posterior deltoids and biceps and triceps brachii. The following EMG differences or trends were observed: For deltoid anterior: ~11% lower for seated barbell versus dumbbell (p = 0.038), ~15% lower in standing barbell versus dumbbell (p < 0.001), ~8% lower for seated versus standing dumbbells (p = 0.070); For medial deltoid, ~7% lower for standing barbell versus dumbbells (p = 0.050), ~7% lower for seated versus standing barbell (p = 0.062), 15% lower for seated versus standing dumbbell (p = 0.008); For posterior deltoid: ~25% lower for seated versus standing barbell (p < 0.001), ~24% lower for seated versus standing dumbbells (p = 0.002); For biceps, ~33% greater for seated barbell versus dumbbells (p = 0.002), 16% greater for standing barbell versus dumbbell (p = 0.074), ~23% lower for seated versus standing dumbbells (p < 0.001); For triceps, ~39% greater for standing barbell versus dumbbells (p < 0.001), ~20% lower for seated versus standing barbell (p = 0.094). 1-RM strength for standing dumbbells was ~7% lower than standing barbell (p = 0.002) and ~10% lower than seated dumbbells (p < 0.001). In conclusion, the exercise with the greatest stability requirement (standing and dumbbells) demonstrated the highest neuromuscular activity of the deltoid muscles, although this was the exercise with the lowest 1-RM strength.

The purpose of the study was to compare 6-repetition maximum (6RM) loads and muscle activity in bench press on 3 surfaces, namely, stable bench, balance cushion, and Swiss ball. Sixteen healthy, resistance-trained men (age 22.5 ± 2.0 years, stature 1.82 ± 6.6 m, and body mass 82.0 ± 7.8 kg) volunteered for 3 habituation/strength testing sessions and 1 experimental session. In randomized order on the 3 surfaces, 6RM strength and electromyographic activity of pectoralis major, deltoid anterior, biceps brachii, triceps brachii, rectus abdominis, oblique external and erector spinae were assessed. Relative to stable bench, the 6RM strength was approximately 93% for balance cushion (p ≤ 0.001) and approximately 92% for Swiss ball (p = 0.008); the pectoralis major electromyographic (EMG) activity was approximately 90% using the balance cushion (p = 0.080) and approximately 81% using Swiss ball (p = 0.006); the triceps EMG was approximately 79% using the balance cushion (p = 0.028) and approximately 69% using the Swiss ball (p = 0.002). Relative to balance cushion, the EMG activity in pectoralis, triceps, and erector spinae using Swiss ball was approximately 89% (p = 0.016), approximately 88% (p = 0.014) and approximately 80% (p = 0.020), respectively. In rectus abdominis, the EMG activity relative to Swiss ball was approximately 69% using stable bench (p = 0.042) and approximately 65% using the balance cushion (p = 0.046). Similar EMG activities between stable and unstable surfaces were observed for deltoid anterior, biceps brachii, and oblique external. In conclusion, stable bench press had greater 6RM strength and triceps and pectoralis EMG activity compared with the unstable surfaces. These findings have implications for athletic training and rehabilitation, because they demonstrate an inferior effect of unstable surfaces on muscle activation of prime movers and strength in bench press. If an unstable surface in bench press is desirable, a balance cushion should be chosen instead of a Swiss ball.

The purpose of the study was to compare force output and muscle activity of leg and trunk muscles in isometric squats executed on stable surface (i.e., floor), power board, BOSU ball, and balance cone. Fifteen healthy men (23.3 ± 2.7 years, mass: 80.5 ± 8.5 kg, height: 1.81 ± 0.09 m) volunteered. The force output and electromyographic (EMG) activities of the rectus femoris, vastus medialis, vastus lateralis, biceps femoris, soleus, rectus abdominis, oblique external, and erector spinae were assessed. The order of the surfaces was randomized. One familiarization session was executed before the experimental test. Compared with stable surface (749 ± 222 N), the force output using power board was similar (-7%, p = 0.320) but lower for BOSU ball (-19%, p = 0.003) and balance cone (-24%, p ≤ 0.001). The force output using BOSU ball and balance cone was approximately 13% (p = 0.037) and approximately 18% (p = 0.001) less than the power board. There were similar EMG activities between the surfaces in all muscles except for rectus femoris, in which stable squat provided greater EMG activity than did the other exercises (p = 0.004-0.030). Lower EMG activity was observed in the rectus femoris using balance cone compared with the BOSU ball (p = 0.030). In conclusion, increasing the instability of the surface during maximum effort isometric squats usually maintains the muscle activity of lower-limb and superficial trunk muscles although the force output is reduced. This suggests that unstable surfaces in the squat may be beneficial in rehabilitation and as a part of periodized training programs, because similar muscle activity can be achieved with reduced loads.

The purpose was to study the effect of a sling exercise training (SET)-based core stability program on maximal throwing velocity among female handball players. Twenty-four female high-school handball players (16.6 ± 0.3 years, 63 ± 6 kg, and 169 ± 7 cm) participated and were initially divided into a SET training group (n = 14) and a control group (CON, n = 10). Both groups performed their regular handball training for 6 weeks. In addition, twice a week, the SET group performed a progressive core stability-training program consisting of 6 unstable closed kinetic chain exercises. Maximal throwing velocity was measured before and after the training period using photocells. Maximal throwing velocity significantly increased 4.9% from 17.9 ± 0.5 to 18.8 ± 0.4 m·s in the SET group after the training period (p < 0.01), but was unchanged in the control group (17.1 ± 0.4 vs. 16.9 ± 0.4 m·s). These results suggest that core stability training using unstable, closed kinetic chain movements can significantly improve maximal throwing velocity. A stronger and more stable lumbopelvic-hip complex may contribute to higher rotational velocity in multisegmental movements. Strength coaches can incorporate exercises exposing the joints for destabilization force during training in closed kinetic chain exercises. This may encourage an effective neuromuscular pattern and increase force production and can improve a highly specific performance task such as throwing.