title: Muscle inactivity and activity patterns after sedentary time--targeted randomized controlled trial.
abstract: OBJECTIVE
  Interventions targeting sedentary time are needed. We used detailed EMG recordings to study the short-term effectiveness of simple sedentary time-targeted tailored counseling on the total physical activity spectrum.
  
  
  METHODS
  This cluster randomized controlled trial was conducted between 2011 and 2013 (InPact, ISRCTN28668090), and short-term effectiveness of counseling is reported in the present study. A total of 133 office workers volunteered to participate, from which muscle activity data were analyzed from 48 (intervention, n = 24; control, n = 24). After a lecture, face-to-face tailored counseling was used to set contractually binding goals regarding breaking up sitting periods and increasing family based physical activity. Primary outcome measures were assessed 11.8 ± 1.1 h before and a maximum of 2 wk after counseling including quadriceps and hamstring muscle inactivity time, sum of the five longest muscle inactivity periods, and light muscle activity time during work, commute, and leisure time.
  
  
  RESULTS
  Compared with those in the controls, counseling decreased the intervention group's muscle inactivity time by 32.6 ± 71.8 min from 69.1% ± 8.5% to 64.6% ± 10.9% (whole day, P < 0.05; work, P < 0.05; leisure, P < 0.05) and the sum of the five longest inactivity periods from 35.6 ± 14.8 to 29.7 ± 10.1 min (whole day, P < 0.05; leisure, P < 0.01). Concomitantly, light muscle activity time increased by 20.6 ± 52.6 min, from 22.2% ± 7.9% to 25.0% ± 9.7% (whole day, P < 0.05; work, P < 0.01; leisure, P < 0.05), and during work time, average EMG amplitude (percentage of EMG during maximal voluntary isometric contraction (MVC) (%EMG MVC)) increased from 1.6% ± 0.9% to 1.8% ± 1.0% (P < 0.05) in the intervention group compared with that in the controls.
  
  
  CONCLUSIONS
  A simple tailored counseling was able to reduce muscle inactivity time by 33 min, which was reallocated to 21 min of light muscle activity. During work time, average EMG amplitude increased by 13%, reaching an average of 1.8% of EMG MVC. If maintained, this observed short-term effect may have health-benefiting consequences.
authors.affiliation: 1Neuromuscular Research Center, Department of Biology of Physical Activity, University of Jyväskylä, Jyväskylä, FINLAND; 2Department of Sport Sciences, University of Jyväskylä, Jyväskylä, FINLAND; and 3Gerontology Research Center, Department of Health Sciences, University of Jyväskylä, Jyväskylä, FINLAND.
authors.forename: Arto J
authors.initials: AJ
authors.lastname: Pesola
authors.forename: Arto
authors.initials: A
authors.lastname: Laukkanen
authors.forename: Piia
authors.initials: P
authors.lastname: Haakana
authors.forename: Marko
authors.initials: M
authors.lastname: Havu
authors.forename: Arja
authors.initials: A
authors.lastname: Sääkslahti
authors.forename: Sarianna
authors.initials: S
authors.lastname: Sipilä
authors.forename: Taija
authors.initials: T
authors.lastname: Finni
mesh_terms: D000203:Activities of Daily Living; D000328:Adult; D003376:Counseling; D004576:Electromyography; D005260:Female; D006801:Humans; D007537:Isometric Contraction; D007899:Leisure Activities; D008297:Male; D008875:Middle Aged; D009043:Motor Activity / Q000502:physiology*; D018482:Muscle, Skeletal / Q000502:physiology*; D052097:Quadriceps Muscle / Q000502:physiology; D057185:Sedentary Behavior