Effects of Variable-Resistance Training Versus Constant-Resistance Training on Maximum Strength: A Systematic Review and Meta-Analysis

Analysis of Velocity, Power and Skin Temperature in Paralympic Powerlifting Athletes with Fixed and Variable Resistance

Variable resistance training has been widely used in athletic preparation.

OBJECTIVES

To analyze the use of currents (VRT) and the traditional method (TRAD) on speed, power and temperature in a training session.

METHODS

Fourteen paralympic powerlifting (PP) athletes took part over three weeks. In week 1, familiarization and 1RM tests took place, and, in weeks 2 and 3, pre- and post-training took place, where the propulsive mean velocity and power and temperatures were assessed before and after, at 24 h and 48 h.

RESULTS

There was a difference in the sternal pectoral temperatures before and after VRT (p = 0.040) and at 48 h for TRAD and VRT (p = 0.018); in the clavicular pectoralis before and after VRT and TRAD (p = 0.003); in the anterior deltoid after and at 48 h for TRAD and VRT (p = 0.026 and p = 0.017); and in the triceps after and at 24 h and 48 h between TRAD and VRT (p = 0.005). In the training series, the MPV was significant in TRAD between Set1 and Set5 (p = 0.003), in training (VRT) between Set1 and Set5 (p = 0.001) and in Set5 between the methods (p = 0.047). For power, there was a difference between Set1 and 5 in TRAD (p = 0.016) and VRT (p = 0.002).

CONCLUSION

We conclude that training with currents (VRT) promoted greater muscle fatigue when compared to traditional training.

Accommodating resistance is more effective than free weight resistance to induce post-activation performance enhancement in squat jump performance after a short rest interval

Background/objectives

Prior work regarding post-activation performance enhancement (PAPE) has shown that various resistance training methods and conditioning activities may induce a PAPE effect such as free weight resistance, accommodating resistance or isoinertial resistance. However, the accommodating resistance and other types of resistance have rarely been directly compared. Thus, the aim of this study was to compare the effects of two different conditioning activities (CA) - a trap bar deadlift with (FW + AR condition) or without (FW condition) accommodating resistance - on subsequent squat jump (SJ) performance after a short rest interval of 90s.

Methods

The study had a cross-over design and fifteen strength trained males (mean age: 22.9 ± 2.1 years; mean relative strength level 2.01 ± 0.27 kg/body mass) participated in one familiarization, two experimental and one control session (CNTR condition). Two CAs were implemented throughout the study - a single set of 3 repetitions of a trap bar deadlift at 80 % of 1RM using solely free weight resistance or with the addition of approximately 15 % of 1RM elastic band tension. The SJ measurements were performed at the baseline and 90s after CAs.

Results

The FW + AR condition significantly improved subsequent SJ performance (p < 0.05, effect size 0.34) whereas the FW and CNTR conditions were found to be ineffective to acutely enhance performance.

Conclusions

Our results suggest that the addition of accommodating resistance is superior to free weight resistance in order to acutely improve jump performance after a 90s rest interval. To observe the performance enhancement effect with solely free weight resistance it should be considered to introduce alteration in loading strategies or possibly lengthening the rest interval.