AUTHOR=Yang Yifan , Bay Pang B. , Wang Yongtai R. , Huang Junli , Teo Hilary W. J. , Goh Jorming 

TITLE=Effects of Consecutive Versus Non-consecutive Days of Resistance Training on Strength, Body Composition, and Red Blood Cells

JOURNAL=Frontiers in Physiology

VOLUME=9

YEAR=2018

URL=https://www.frontiersin.org/journals/physiology/articles/10.3389/fphys.2018.00725

DOI=10.3389/fphys.2018.00725

ISSN=1664-042X

ABSTRACT=<p>Health authorities worldwide recommend 2–3 days per week of resistance training (RT) performed ∼48–72 h apart. However, the influence of recovery period between RT sessions on muscle strength, body composition, and red blood cells (RBCs) are unclear.</p><p><bold>Aim:</bold> Examine the effects of three consecutive (C) or non-consecutive (NC) days of RT per week for 12 weeks on strength, body composition, and RBCs.</p><p><bold>Methods:</bold> Thirty young, healthy and recreationally active males were randomly assigned to 3 C (∼24 h between sessions) or NC (∼48–72 h between sessions) days of RT per week for 12 weeks. Both groups performed three sets of 10 repetitions at 10-repetition maximum (RM) of leg press, latissimus pulldown, leg curl, shoulder press, and leg extension for each session. Ten RM and body composition were assessed pre- and post-RT. RBC parameters were measured on the first session before RT, and 0 and 24 h post-3rd session in untrained (week 1) and trained (week 12) states.</p><p><bold>Results:</bold> No training × group interaction was found for all strength and body composition parameters (<italic>p</italic> = 0.075–0.974). Training increased strength for all exercises, bone mineral density, and total body mass via increased lean and bone mass (<italic>p</italic> &lt; 0.001). There was no interaction (<italic>p</italic> = 0.076–0.994) and RT induced temporal changes in all RBC parameters (<italic>p</italic> &lt; 0.001–0.003) except RBC corrected for plasma volume changes (time × training interaction; <italic>p</italic> = 0.001). Training increased hematocrit and lowered mean corpuscular hemoglobin and mean corpuscular hemoglobin concentration (<italic>p</italic> = 0.001–0.041) but did not alter uncorrected RBC, hemoglobin, mean corpuscular volume and RBC distribution width (<italic>p</italic> = 0.178–0.797).</p><p><bold>Conclusion:</bold> Both C and NC RT induced similar improvements in strength and body composition, and changes in RBC parameters.</p>