Carvalho Joyce F, Masuda Masako O, Pompeu Fernando A M S
Laboratório de Eletrofisiologia Cardíaca Antonio Paes de Carvalho, Instituto de Biofísica Carlos Chagas Filho, Brazil.
Comp Biochem Physiol A Mol Integr Physiol. 2005 Apr;140(4):409-13. doi: 10.1016/j.cbpb.2004.12.002. Epub 2005 Mar 31.
We propose a protocol for determination of lactate threshold (LT) and test the validity of one aerobic training based on LT in rats. In group I, V(LTi) (velocity at LT before training) was determined in all rats (n=10), each rat training at its own V(LTi) and in group II, animals (n=7) ran at 15 m min(-1), the mean V(LTi) of group I. The training consisted of daily runs at V(LTi) for 50 min, 5 days/week, for 4 weeks. In group I, this program increased V(LT) (V(LTi) 14.90+/-1.49 m min(-1) and V(LTf), after training, 22.60+/-1.17 m min(-1)) and the velocity at exhaustion (19.50+/-1.63 m min(-1) and 27.60+/-1.17 m min(-1)). [Lactate] at LT (2.62+/-0.43 mmol L(-1) versus 2.11+/-0.15 mmol L(-1)) and relative values of LT (76+/-3% versus 82+/-2%) stayed unaltered. In group II the V(LTf) was 20+/-1.8 m.mim(-1), the [lactate] at the LT, 2.02+/-0.17 mmol.L(-1); the exhaustion speed, 23.57+/-2.11 m.mim(-1) and relative value of LT, 82.71+/-2.29%. There were no significant differences in these parameters between groups I and II. Thus, this protocol based on LT is effective and the mean V(LT) determined in a small number of healthy untrained rats can be used for aerobic training in a larger group of healthy animals of same gender and age.
我们提出了一种测定乳酸阈值(LT)的方案,并在大鼠中测试了基于LT的一种有氧训练的有效性。在第一组中,测定了所有大鼠(n = 10)的V(LTi)(训练前LT时的速度),每只大鼠以其自身的V(LTi)进行训练;在第二组中,动物(n = 7)以第一组的平均V(LTi)即15 m min⁻¹的速度奔跑。训练包括每天以V(LTi)的速度奔跑50分钟,每周5天,共4周。在第一组中,该训练方案提高了V(LT)(训练前V(LTi)为14.90±1.49 m min⁻¹,训练后V(LTf)为22.60±1.17 m min⁻¹)以及力竭速度(19.50±1.63 m min⁻¹和27.60±1.17 m min⁻¹)。LT时的[乳酸](2.62±0.43 mmol L⁻¹对2.11±0.15 mmol L⁻¹)和LT的相对值(76±3%对82±2%)保持不变。在第二组中,V(LTf)为20±1.8 m min⁻¹,LT时的[乳酸]为2.02±0.17 mmol L⁻¹;力竭速度为23.57±2.11 m min⁻¹,LT的相对值为82.71±2.29%。第一组和第二组在这些参数上没有显著差异。因此,这种基于LT的方案是有效的,并且在少量健康未训练大鼠中测定的平均V(LT)可用于更大组相同性别和年龄的健康动物的有氧训练。