Inclusion of repeated 30-s maximal sprints in prolonged low-intensity endurance cycling improves sprint-ability and 5-min all-out performance in elite cyclists.

Introduction
To enhance performance, elite cyclists increase low-intense training (LIT) volume for short periods, often organised as training camps [1]. Adding repeated sprint sessions to LIT has been shown to increase both sprint-ability and 40-km time trial (TT) performance in well-trained cyclists [4]. However, the effect of including repeated sprints within LIT-sessions has not previously been investigated during training camps with high volumes of LIT. To achieve super-compensation and avoid overreaching after periods of high training load, a subsequent reduction in training volume (tapering) by 41-60% is recommended [2]. As little as 1 wk of tapering has led to hypervolemia [2], improvements in maximal oxygen uptake (VO2max) and TT performance [3] in well-trained cyclists. The aim of this study was to compare the effects of a 14-d high-volume training camp with either a) inclusion of 30-s maximal sprints within LIT-sessions or b) work-matched LIT-sessions on 5-min all-out performance, sprint-ability, physiological measurements and haematological values in elite cyclists.
Methods
18 elite cyclists (VO2max: 75±5mL·min-1·kg-1) were equally split into a Sprint group (S) performing 10±2 x 30-s maximal sprints on 5 of the LIT bouts and a Control group (C) performing work- matched LIT during a 14-d training camp. Compared to baseline, training volume was increased by approximately 50% in both groups during the 14-days, and thereafter decreased by approximately 60% compared to baseline training in the 10-d taper. Testing was performed on a Lode Excalibur cycle ergometer and oxygen uptake was measured using a Jaeger Oxycon Pro. Haematological values were determined using the CO-rebreathing method [5].
Results
S increased the 5-min all-out power by 3±4% and mean sprint power output by 4±4 % (P<0.05), whereas no corresponding changes were observed in C (-1±5% and 0±4%, respectively) from pre to after the taper (post). Red blood cell mass increased equally in both groups by 4±4% (P<0.05), while haemoglobin mass, plasma volume, blood volume, last minute power output of an incremental test to exhaustion (Wmax), VO2max, power output- and fractional utilization of VO2max at 4 mmol [La-] were unchanged in both groups from pre to post.
Conclusion
Inclusion of repeated 30-s maximal sprints in 5 LIT sessions improved both sprint-ability and 5-min all-out performance compared to work-matched LIT-sessions during a 14-d high-volume training camp.