Department of Physiology, Trinity Biomedical Sciences Institute, Trinity College Dublin, Dublin 2, Ireland.
Appl Physiol Nutr Metab. 2012 Aug;37(4):599-609. doi: 10.1139/h2012-012. Epub 2012 May 7.
Supervised exercise (SE) in patients with type 2 diabetes improves oxygen uptake kinetics at the onset of exercise. Maintenance of these improvements, however, has not been examined when supervision is removed. We explored if potential improvements in oxygen uptake kinetics following a 12-week SE that combined aerobic and resistance training were maintained after a subsequent 12-week unsupervised exercise (UE). The involvement of cardiac output (CO) in these improvements was also tested. Nineteen volunteers with type 2 diabetes were recruited. Oxygen uptake kinetics and CO (inert gas rebreathing) responses to constant-load cycling at 50% ventilatory threshold (V(T)), 80% V(T), and mid-point between V(T) and peak workload (50% Δ) were examined at baseline (on 2 occasions) and following each 12-week training period. Participants decided to exercise at a local gymnasium during the UE. Thirteen subjects completed all the interventions. The time constant of phase 2 of oxygen uptake was significantly faster (p < 0.05) post-SE and post-UE compared with baseline at 50% V(T) (17.3 ± 10.7 s and 17.5 ± 5.9 s vs. 29.9 ± 10.7 s), 80% V(T) (18.9 ± 4.7 and 20.9 ± 8.4 vs. 34.3 ± 12.7s), and 50% Δ (20.4 ± 8.2 s and 20.2 ± 6.0 s vs. 27.6 ± 3.7 s). SE also induced faster heart rate kinetics at all 3 intensities and a larger increase in CO at 30 s in relation to 240 s at 80% V(T); and these responses were maintained post-UE. Unsupervised exercise maintained benefits in oxygen uptake kinetics obtained during a supervised exercise in subjects with diabetes, and these benefits were associated with a faster dynamic response of heart rate after training.
在 2 型糖尿病患者中进行监督下的运动（SE）可改善运动起始时的摄氧量动力学。然而，当监督停止时，这些改善是否能维持尚不清楚。我们探讨了在结合有氧和抗阻训练的 12 周 SE 后，随后进行 12 周非监督运动（UE）是否能维持摄氧量动力学的潜在改善。还测试了心输出量（CO）在这些改善中的作用。招募了 19 名 2 型糖尿病志愿者。在基线（2 次）和每次 12 周训练后，通过惰性气体再呼吸法检测恒负荷踏车运动时的摄氧量动力学和 CO 反应，运动负荷分别为 50%通气阈（V(T)）、80%V(T)和 V(T)与峰值工作之间的中点（50%Δ）。参与者决定在 UE 期间在当地健身房运动。13 名受试者完成了所有干预措施。与基线相比，在 50%V(T)（17.3 ± 10.7 s 和 17.5 ± 5.9 s 比 29.9 ± 10.7 s）、80%V(T)（18.9 ± 4.7 和 20.9 ± 8.4 s 比 34.3 ± 12.7s）和 50%Δ（20.4 ± 8.2 s 和 20.2 ± 6.0 s 比 27.6 ± 3.7 s）时，SE 还可使 2 相的时间常数更快，在所有 3 个强度下，SE 还可使心率动力学更快，在 80%V(T)时，在 30 s 时的 CO 增加更大，而在 240 s 时的 CO 增加更大；这些反应在 UE 后仍能维持。在糖尿病患者中，非监督运动维持了监督运动获得的摄氧量动力学的益处，这些益处与训练后心率的更快动力学反应有关。
