Effects of Including Sprints in LIT Sessions during a 14-d Camp on Muscle Biology and Performance Measures in Elite Cyclists.

Abstract

PURPOSE\nThis study investigated the effects of including sprints within low-intensity training (LIT)-sessions during a 14-d training camp focusing on LIT, followed by 10 days recovery (Rec), on performance and performance-related measures in elite cyclists.\n\n\nMETHODS\nDuring the camp, a sprint training group (SPR, n = 9) included 12x30-s maximal sprints during five LIT-sessions, whereas a control group (CON, n = 9) performed distance-matched LIT only. Training load was equally increased in both groups by 48 ± 27% during the training camp and subsequently decreased by -56 ± 23% during the recovery period compared to habitual training. Performance tests were conducted before the training camp (Pre) and after Rec. Muscle biopsies, haematological measures and stress/recovery questionnaires were collected Pre and after the camp (Post).\n\n\nRESULTS\n30-s sprint (SPR vs CON: 4 ± 4%, p < 0.01) and 5-min mean power (SPR vs CON: 4 ± 8%, p = 0.04) changed differently between groups. In muscle, Na+-K+β1 protein content changed differently between groups, decreasing in CON compared to SPR (-8 ± 14%, p = 0.04), while other proteins showed similar changes. SPR and CON displayed similar increases in red blood cell volume (SPR: 2.6 ± 4.7%, p = 0.07, CON: 3.9 ± 4.5%, p = 0.02) and VO2 at 4 mmol·L-1 [BLa-] (SPR: 2.5 ± 3.3%, p = 0.03, CON: 2.2 ± 3.0%, p = 0.04). No changes were seen for VO2max, Wmax, haematological measures, muscle enzyme activity and stress/recovery measures.\n\n\nCONCLUSION\nInclusion of 30-s sprints within LIT-sessions during a high-volume training camp affected competition-relevant performance-measures and Na+-K+β1 protein content differently than LIT only, without affecting sport-specific stress/recovery or any other physiological measure in elite cyclists.