The influence of isometric preload on power expressed during bench press in strength-trained men

How to activate the glutes best? Peak muscle activity of acceleration-specific pre-activation and traditional strength training exercises

PURPOSE

Isometric training and pre-activation are proven to enhance acceleration performance. However, traditional strength training exercises do not mirror the acceleration-specific activation patterns of the gluteal muscles, characterized by ipsilateral hip extension during contralateral hip flexion. Therefore, the aim of the study was to determine gluteal muscle activity of acceleration-specific exercises compared to traditional strength training exercises.

METHODS

In a cross-sectional study design, the peak electromyographic activity of two acceleration-specific exercises was investigated and compared to two traditional strength training exercises each for the gluteus maximus and medius. Twenty-four participants from various athletic backgrounds (13 males, 11 females, 26 years, 178 cm, 77 kg) performed four gluteus maximus [half-kneeling glute squeeze (HKGS), resisted knee split (RKS), hip thrust (HT), split squat (SS)] and four gluteus medius [resisted prone hip abduction (RPHA), isometric clam (IC), side-plank with leg abduction (SP), resisted side-stepping (RSS)] exercises in a randomized order.

RESULTS

The RKS (p = 0.011, d = 0.96) and the HKGS (p = 0.064, d = 0.68) elicited higher peak gluteus maximus activity than the SS with large and moderate effects, respectively. No significant differences (p > 0.05) were found between the HT, RKS and HKGS. The RPHA elicited significantly higher gluteus medius activity with a large effect compared to RSS (p < 0.001, d = 1.41) and a moderate effect relative to the SP (p = 0.002, d = 0.78).

CONCLUSION

The acceleration-specific exercises effectively activate the gluteal muscles for pre-activation and strength training purposes and might help improve horizontal acceleration due to their direct coordinative transfer.

Isokinetic strength of shoulder rotator muscles in powerlifters: correlation between isometric and concentric muscle actions

BACKGROUND

Isokinetic strength has been useful to assess muscle function related to sports and prevent injuries. The present study measured the isokinetic isometric and concentric shoulder rotators strength, agonist/antagonist ratio, and examined the relationships between isometric and concentric peak torque, and agonist/antagonist ratio in powerlifters compared to a control group.

METHODS

The participants were divided into two groups: powerlifters group (n=14) and physically active group (n=9). Participants' were evaluated on isokinetic dynamometer for isometric, and concentric (two velocities, 60°/s and 180°/s) strength of shoulder external (ER) internal rotation (IR). Isometric contractions lasted 10 seconds, and concentric modes were 5 repetitions.

RESULTS

Bilateral significant differences, between dominant and non-dominant side, were found in ER peak torque at isometric mode in powerlifters group (p=0.021). Powerlifters showed higher IR peak torque at isometric mode in dominant (p=0.040) and non-dominant side (p=0.014) than physically active group. Pearson correlations between isometric peak torque and concentric velocities ranged between 0.49 and 0.89 for powerlifters group, and between 0.73 and 0.93 for physically active group. For agonist/antagonist ratio, pearson correlation ranged between 0.47 and 0.83 for powerlifters group, and between 0.48 and 0.86 for physically active group.

CONCLUSIONS

The bilateral differences in ER movement at isometric mode in powerlifters suggest that exercises for shoulder rotators must be included on training for joint safety and balance between sides despite isometric shoulder rotators strength in powerlifters was higher than physically active individuals. Results presented positive correlation between both muscle actions, isometric and concentric, in peak torque and agonist/antagonist ratio.

A Comparison between Elite Swimmers and Kayakers on Upper Body Push and Pull Strength and Power Performance

The aim of the present study was to compare the load-power curve expressed at bench press (PR) and prone bench pull (PU) between elite swimmers and kayakers. Another aim was to calculate the strength and power PR/PU ratio in the same populations. Fifteen elite swimmers (SW: age = 23.8 ± 2.9 y; body mass = 82.8 ± 5.6 kg; body height = 184.1 ± 4.6 cm) and 13 elite kayakers (KA: age = 23.8 ± 2.9 y; body mass = 91.0 ± 3.5 kg; body height = 180.1 ± 5.4 cm) were assessed for PR 1RM and PU 1RM. They were then assessed for power produced at 40, 60 and 80% of 1RM in both PR and PU. The area under the load-power curve (AUC) and PR/PU ratios were calculated for both the SW and KA groups. The KA group showed significantly higher PR1RM (+18.2%; p = 0.002) and PU1RM (+25.7%; p < 0.001) compared to the SW group. Significant group differences were also detected for PUAUC (p < 0.001) and for the PR/PU power ratio (p < 0.001). No significant group differences were detected for PRAUC (p = 0.605) and for the PR/PU strength ratio (p = 0.065; 0.87 and 0.82 in SW and KA, respectively). The present findings indicate that elite KA were stronger and more powerful than elite SW in the upper body. Not consistently with other athletic populations, both KA and SW athletes were stronger and more powerful in upper body pull compared to push moves.