ACUTE AND LONG-TERM EFFECTS OF BLOOD FLOW RESTRICTED TRAINING ON HEAT SHOCK PROTEINS: FAILURE versus NON-FAILURE PROTOCOL

Introduction: The stress imposed on muscle fibres during low-load blood flow restricted resistance exercise (BFRRE) performed to failure seems to preferentially stress type I fibres (Cumming et al., 2014). Therefore, the aim of this study was to compare the effect of a failure (FA) vs non-failure (NON-FA) BFRRE protocol on heat-shock protein responses in the exercising muscles.
Methods: Sixteen untrained men (18-45yrs) completed 14 BFRRE sessions divided into 2 blocks of 7 sessions in 5 days, interspersed by 10 days of rest. Legs were randomly assigned to either FA (4 sets to voluntary failure) or NO protocol (30-, 15-, 15-, 15 reps) using unilateral knee extensions at 20% of 1RM with 30s rest between sets. BFRRE was conducted with partial blood flow restriction (100 mmHg) induced by a 15cm wide pressure cuff. Muscle biopsies were collected before, during and post intervention and analysed for aB-crystallin (aBc), HSP70 and MHC by immunofluorescence.