Crowe Louis, Caulfield Brian
Institute of Sport and Health, University College Dublin, Dublin, Ireland.
BMJ Case Rep. 2012 Mar 27;2012:bcr0320113939. doi: 10.1136/bcr.03.2011.3939.
We live in a time of plenty. During evolution, periods of hunger and simultaneously high activity levels would combine giving a stimulus which is absent from modern lifestyles. This is potentially connected with abnormal glucose metabolism. It was hypothesised that simultaneous fasting and aggressive aerobic neuromuscular electrical stimulation (NMES) exercise, until metabolic exhaustion, may be an acceptable modern equivalent. A healthy subject fasted for 44 h (water allowed) during which he undertook three aerobic NMES sessions at >50%VO(2max); heart rate >160 bpm. Metabolic gas analysis of a comparable session in the non-fasting state showed 100% carbohydrate substrate utilisation. With fasting the NMES exercise consumed mostly fat-up to 100% fat utilisation at 42 h. This clear shift away from using carbohydrate as a substrate and hypoglycaemia may indicate that carbohydrate stores are nearly depleted. The authors postulate that this may constitute a metabolic super stimulus mimicking the famine-activity periods of our ancestors.
我们生活在一个物质充裕的时代。在进化过程中,饥饿时期与高活动水平同时出现,会产生一种现代生活方式中不存在的刺激。这可能与异常的葡萄糖代谢有关。据推测,同时进行禁食和积极的有氧神经肌肉电刺激(NMES)运动,直至代谢耗竭,可能是现代可接受的等效方式。一名健康受试者禁食44小时(允许饮水),在此期间他进行了三次有氧NMES训练,强度大于50%VO₂max;心率大于160次/分钟。对非禁食状态下类似训练的代谢气体分析显示,碳水化合物底物利用率为100%。禁食时,NMES运动主要消耗脂肪——在42小时时脂肪利用率高达100%。这种明显从使用碳水化合物作为底物的转变以及低血糖可能表明碳水化合物储备几乎耗尽。作者推测,这可能构成一种模仿我们祖先饥荒 - 活动时期的代谢超级刺激。