Journal of Trainology
Online ISSN : 2186-5264
ISSN-L : 2186-5264
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Displaying 1-2 of 2 articles from this issue
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  • Nic Martinez, John O’Halloran, Marcus W. Kilpatrick, Bill I. Campbell, ...
    Article type: research-article
    2021 Volume 11 Issue 1 Pages 1-6
    Published: December 24, 2021
    Released on J-STAGE: January 17, 2022
    JOURNAL FREE ACCESS

    Practical blood flow restriction (PBFR) training has been used as a training technique to induce muscular strength and hypertrophy gains while utilizing lighter loads [≤ 40% one repetition maximum (1RM)]. It is unclear if PBFR can be incorporated into traditional training programs to alleviate some exposure to heavy loads. Objective: Compare the impact of a traditional resistance training with the addition of PBFR (TRAD + PBFR) to traditional resistance training without PBFR (TRAD) on maximal bench press and leg press strength. Design and Methods: Participants performed full body training for 4 weeks (2-3x/week). PBFR group performed 62% of sets blood flow restricted at 30% 1RM while the TRAD group performed all sets at an intensity of >70% 1RM. Results: Twenty-one resistance trained individuals (≥ 1 year resistance training) completed the study. For bench press strength, there was no group (TRAD + PBFR vs. TRAD) by time (pre vs. post) interaction (BF10 = 0.32). However, there was a main effect for time (BF10 = 24.04). The TRAD + PBFR group increased strength from 99 ± 29 to 106 ± 23 kg and the traditional training condition increased from 111 ± 27 to 117 ± 24kg. For leg press strength, there was no interaction (BF10 = 0.83). However, there was a main effect for time, with both conditions increasing strength. For the PBFR group strength increased from 372 ± 61 to 423 ± 76 kg and the TRAD group increased strength from 354 ± 87 to 434 ± 96kg. Conclusion: TRAD + PBFR elicited similar strength adaptations compared to TRAD. PBFR may provide a means to exposing the muscle and connective tissue to less overall mechanical stress when incorporated into a traditional heavy resistance training program.

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  • Matthew A. Chatlaong, Grant Mouser J., John P. Bentley, Samuel L. Buck ...
    Article type: research-article
    2022 Volume 11 Issue 1 Pages 7-11
    Published: January 10, 2022
    Released on J-STAGE: January 27, 2022
    JOURNAL FREE ACCESS

    Objectives: To determine if different mechanisms, i.e., changes in one-repetition maximum (1RM) strength (Δ1RM) or vascular conductance (ΔVC), mediate changes in endurance (ΔEND) following training with 70% 1RM (70/0), 15% 1RM (15/0), and 15% 1RM with blood flow restriction using 40% (15/40) or 80% (15/80) arterial occlusion pressure. Design: Secondary analysis of data from a previous training intervention study. Method: Previously, 39 participants trained 2x/week for 8 weeks (4 sets of knee extensions to momentary failure) with 2 of the 4 aforementioned conditions (randomized, 1 per leg). VC, 1RM, and END were tested pre/post-training. A two-wave multiple-mediator model (adjusted for baseline values of 1RM, VC, and END) was constructed to evaluate direct and indirect effects of training on ΔEND (relative to other conditions) with Δ1RM and ΔVC as mediators. Results presented as coefficients (95%CI). Results: The model accounted for 35.3% (p < .001) of the variance in ΔEND. Relative direct effects on ΔEND did not differ across conditions (all p > .231). There was an effect of Δ1RM on ΔEND [0.5 (0.0,0.9) repetitions] and evidence that Δ1RM mediated the effect on ΔEND for 70/0 compared to other conditions [vs. 15/0 = 1.4 (0.1,2.9); 15/40 = 1.4 (0.1,2.7); 15/80 = 1.1 (0.1,2.3) repetitions]. There was no evidence of a relationship between ΔVC and ΔEND [0.02 (-0.10,0.13) repetitions] nor of relative indirect effects through ΔVC when comparing conditions. Conclusions: Differences in Δ1RM translate to increased endurance in the 70/0 condition compared to other conditions, however, differences in ΔVC did not appear to mediate increased endurance across the conditions.

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