title: Early adaptations to six weeks of non-periodized and periodized strength training regimens in recreational males.
abstract: This study compared quadriceps muscle cross-sectional area (CSA) and maximum strength (1RM) after three different short-term strength training (ST) regimens (i.e. non-periodized [NP], traditional-periodization [TP], and undulating-periodization [UP]) matched for volume load in previously untrained individuals. Thirty-one recreationally active males were randomly divided into four groups: NP: n = 9; TP: n = 9; UP: n = 8 and control group (C): n = 5. Experimental groups underwent a 6-week program consisting of two training sessions per week. Muscle strength was assessed at baseline and after the training period. Dominant leg quadriceps CSA was obtained through magnetic resonance imaging (MRI) at baseline and 48h after the last training session.
  
  
  RESULTS
  The 1RM increased from pre to post only in the NP and UP groups (NP = 17.0 %, p = 0.002; UP = 12.9 %, p = 0.03), respectively. There were no significant differences in 1RM for LP and C groups after 6 weeks (TP = 7.7 %, p = 0.58, C = 1.2 %, p = 1.00). The CSA increased from pre to post in all of the experimental groups (NP = 5.1 %, p = 0.0001; TP = 4.6 %, p = 0.001; UP = 5.2 %, p = 0.0001), with no changes observed in the C group (p = 0.93).
  
  
  CONCLUSIONS
  Our results suggest that different ST periodization regimens over a short-term (i.e. 6 weeks), volume load equated conditions seem to induce similar hypertrophic responses regardless of the loading scheme employed. In addition, for those recreational males who need to develop muscle strength in the short-term, the training regimen should be designed properly. Key pointsMuscle hypertrophy occurs within six weeks in recreationally active men regardless the ST training regimen employed.When the total volume is similar, training at greater intensities will demonstrate superior gains in the 1RM performance.Some caution should be exercised when interpreting our findings since long-term periodized regimens could produce different training-induced responses.
authors.affiliation: Laboratory of Adaptations to Strength Training, School of Physical Education and Sport, University of Sao Paulo , SP, Brazil ; Department of Physical Education, Paulista University (UNIP), Sao Paulo , SP, Brazil.
authors.forename: Eduardo O
authors.initials: EO
authors.lastname: Souza
authors.affiliation: Laboratory of Adaptations to Strength Training, School of Physical Education and Sport, University of Sao Paulo , SP, Brazil.
authors.forename: Carlos
authors.initials: C
authors.lastname: Ugrinowitsch
authors.affiliation: Laboratory of Adaptations to Strength Training, School of Physical Education and Sport, University of Sao Paulo , SP, Brazil.
authors.forename: Valmor
authors.initials: V
authors.lastname: Tricoli
authors.affiliation: Laboratory of Adaptations to Strength Training, School of Physical Education and Sport, University of Sao Paulo , SP, Brazil.
authors.forename: Hamilton
authors.initials: H
authors.lastname: Roschel
authors.affiliation: Department of Health Science and Human Performance, University of Tampa , Tampa, FL, USA.
authors.forename: Ryan P
authors.initials: RP
authors.lastname: Lowery
authors.affiliation: Delboni Auriemo Diagnostic Imaging Sector: a division of DASA, Sao Paulo , SP, Brazil.
authors.forename: André Y
authors.initials: AY
authors.lastname: Aihara
authors.affiliation: Delboni Auriemo Diagnostic Imaging Sector: a division of DASA, Sao Paulo , SP, Brazil.
authors.forename: Alberto R S
authors.initials: AR
authors.lastname: Leão
authors.affiliation: Department of Health Science and Human Performance, University of Tampa , Tampa, FL, USA.
authors.forename: Jacob M
authors.initials: JM
authors.lastname: Wilson
keywords: Periodization; exercise prescription; muscle hypertrophy; training load