Participants were required to attend the laboratory on 24 occasions across a period of ≤12 weeks. Visits 1-2 were performed a minimum of 72 h prior to visit 3, and were used to train and familiarise participants in three separate weight-lifting techniques. Muscle tissue samples were collected from participants in visits 3 and 24 for analysis of epigenetic modification and gene expression. In visits 4, 10, 17 and 23, participants were assessed for their 5 repetition maximum (RM) in the three weight-lifting techniques. The remaining visits (5-9, 11-16 and 18-22) were strength training sessions, during which participants followed a lower limb strength training programme. All visits took place a minimum of 48 h apart, with no more than 2 visits occurring in any 7 d period. This programming allowed for a 10 week (2 sessions per week) training programme, with familiarisation included in the 2 weeks prior to this training period. Immediately-post each strength training or assessment visit, the treatment group completed a CWI exposure, while the placebo group participants consumed a sham recovery drink. Throughout the study period, participants were instructed to refrain from any strength-training outside of the prescribed programme and to continue their normal cycling training and dietary routines respectively.
Growth protocol
Muscle tissue samples (~20mg) were collected under local anaethesia from the vastus lateralis muscle midway between the patella and iliac crest using the microbiopsy technique.
Extracted molecule
total RNA
Extraction protocol
Muscle sample preservation and stabilization was assured by the immediate addition of 500 µL of RNALater® solution (ThermoFisher Scientific Inc, Massachusettes, USA). As per manufacturer’s instructions, the vial containing the muscle sample was then left at room temperature for 24 h to allow the RNALater® solution to fully permeate the sample, before being stored at -80°C for later analysis.
Label
biotin
Label protocol
RNA samples were amplified, labeled, hybridized to Affymetrix HG-U133 plus 2.0 GeneChip® microarrays, and scanned using standard protocols (Expression Analysis, Inc., Durham, North Carolina, U.S.A.) to generate raw data files (CEL files).
Hybridization protocol
RNA samples were amplified, labeled, hybridized to Affymetrix HG-U133 plus 2.0 GeneChip® microarrays, and scanned using standard protocols (Expression Analysis, Inc., Durham, North Carolina, U.S.A.) to generate raw data files (CEL files).
Scan protocol
RNA samples were amplified, labeled, hybridized to Affymetrix HG-U133 plus 2.0 GeneChip® microarrays, and scanned using standard protocols (Expression Analysis, Inc., Durham, North Carolina, U.S.A.) to generate raw data files (CEL files).
Description
Gene expression data from vastus lateralis muscle tissue collected after 10 week training (Placebo study arm)
Data processing
Raw data files (CEL files) were analyzed using a battery of data quality checks and samples failing these checks were removed from subsequent analyses. Raw data was then pre-processed using the RMA (Robust Multi-chip Average) pipeline in combination with the most current re-annotated probeset definitions.
