The 33 distance covered while running at high-speed during a football match was reduced by 34 8.4% during the initial part of the second half compared with the initial part of the first 35 half (Weston et al., 2011). Furthermore, the sprint performance was reduced by 2.4% at 36 the onset of the second half compared with at the onset of the first half (Mohr, Krustrup, 37 Nybo, Nielsen, & Bangsbo, 2004). These reductions resulted from the passive recovery 38 during half-time and have been associated with physiological changes, including loss of 39 muscle (T m ) and core temperatures (T c ), decrement of muscle activation and reduction 40 of oxygen availability in the muscle (

We compared the effects of prolonged sitting with the effects of sitting interrupted by regular walking and the effects of prolonged sitting after continuous walking on postprandial triglyceride in postmenopausal women. 15 participants completed 3 trials in random order: 1) prolonged sitting, 2) regular walking, and 3) prolonged sitting preceded by continuous walking. During the sitting trial, participants rested for 8 h. For the walking trials, participants walked briskly in either twenty 90-sec bouts over 8 h or one 30-min bout in the morning (09:00-09:30). Except for walking, both exercise trials mimicked the sitting trial. In each trial, participants consumed a breakfast (08:00) and lunch (11:00). Blood samples were collected in the fasted state and at 2, 4, 6 and 8 h after breakfast. The serum triglyceride incremental area under the curve was 15 and 14% lower after regular walking compared with prolonged sitting and prolonged sitting after continuous walking (4.73±2.50 vs. 5.52±2.95 vs. 5.50±2.59 mmol/L∙8 h respectively, main effect of trial: P=0.023). Regularly interrupting sitting time with brief bouts of physical activity can reduce postprandial triglyceride in postmenopausal women.

Yanaoka, T, Hamada, Y, Kashiwabara, K, Kurata, K, Yamamoto, R, Miyashita, M, and Hirose, N. Very-short-duration, low-intensity half-time re–warm up increases subsequent intermittent sprint performance. J Strength Cond Res 32(11): 3258–3266, 2018—This study investigated the effect of very-short-duration, low-intensity half-time re–warm up (RW) on subsequent intermittent sprint performance. Using a randomized cross-over design, 11 healthy men performed 3 trials. In the experimental trials, participants performed the first 40-minute intermittent exercise followed by a 15-minute half-time. The interventions at half-time were 15 minutes of seated rest (control), 3 minutes of moderate-intensity RW (cycling at 60% of maximal oxygen uptake [V̇o2max]; [60% RW]), and 3 minutes of low-intensity RW (cycling at 30% of V̇o2max; [30% RW]). After half-time, participants performed the Cycling Intermittent-Sprint Protocol (CISP), which consisted of 10 seconds of rest, 5 seconds of maximal sprint, and 105 seconds of active recovery at 50% of V̇o2max, with the cycles repeated over the 20-minute duration. The mean work and electromyogram amplitude during the sprint in the CISP were higher in both RW trials than in the control trial (p < 0.05). Muscle temperature, estimated from the skin temperature, at 60 minutes was higher in the 60% RW trial than in the control and 30% RW trials (p < 0.05). The mean change in oxygenated hemoglobin concentration during active recovery at 55–65 minutes tended to be higher in both RW trials than in the control trial (60% RW trial: p = 0.06, 30% RW trial: p = 0.06). In conclusion, very-short-duration, low-intensity RW increased intermittent sprint performance after the half-time, in comparison with a traditional passive half-time practice, and was as effective as a moderate-intensity RW when matched for total duration.