This study examined the effects of sustained high-intensity interval training (HIT) on the athletic performances and fuel utilisation of eight male endurance-trained cyclists. Before HIT, each subject undertook three baseline peak power output Wpeak tests and two simulated 40-km time-trial cycling performance (TT40) tests, of which the variabilities were 1.5 (1.3)% and 1.0 (0.5)%, respectively [mean (SD)]. Over 6 weeks, the cyclists then replaced 15 (2)% of their 300 (66) km.week-1 endurance training with 12 HIT sessions, each consisting of six to nine 5-min rides at 80% of Wpeak, separated by a l-min recovery. HIT increased Wpeak from 404 (40) to 424 (53) W (P < 0.01) and improved TT40 speeds from 42.0 (3.6) to 43.0 (4.2) km.h-1 (P < 0.05). Faster TT40 performances were due to increases in both the absolute work rates from 291 (43) to 327 (51) W (P < 0.05) and the relative work rates from 72.6 (5.3)% of pre-HIT Wpeak to 78.1 (2.8)% of post-HIT Wpeak (P < 0.05). HIT decreased carbohydrate (CHO) oxidation, plasma lactate concentration and ventilation when the cyclists rode at the same absolute work rates of 60, 70 and 80% of pre-HIT Wpeak (P < 0.05), but not when they exercised at the same relative (% post-HIT Wpeak) work rates. Thus, the ability of the cyclists to sustain higher percentages of Wpeak in TT40 performances after HIT was not due to lower rates of CHO oxidation. Higher relative work rates in the TT40 rides following HIT increased the estimated rates of CHO oxidation from approximately 4.3 to approximately 5.1 g.min-1.

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Imaging is essential in the diagnosis, management, surgical planning and eventual outcome in patients with anorectal malformation (ARM). This article outlines the imaging that may be required and the information needed by the surgeon to attain the best possible surgical outcome. ARM encompasses a wide spectrum of congenital malformations relating to the distal rectum and anus as well as the urinary and or gynaecological systems. The malformations range from a relatively simple perineal fistula with the potential for an excellent functional outcome, to complex cloacal malformation that requires specialist care and intervention. Approximately half of these children will have associated abnormalies. In the first 24–48 hours of life, imaging is used to determine if any associated anomalies are severe enough to preclude an operation, and what operation will be required so that the child can grow as normally as possible. If a colostomy is done, pre-definitive repair imaging in the form of a high-pressure distal colostogram determines the surgical approach required to repair the malformation. In more complicated cases of cloacal malformation, advanced imaging in the form of MRI or 3D fluoroscopy is valuable. In the South African setting, 2D fluoroscopy with the surgeon present is adequate to help in planning for the surgical management. Communication between the radiologist and paediatric surgeon is essential to ensure that such patients have the best possible outcome.