Exactly. To cool down means to do easy exercises after doing an intense exercise.

完全正确。" cool down" 意思是在高强度运动完后的放松运动。

Well, first off, don't try to do traditional academic learning during intense exercise.

首先，不要试图在剧烈运动期间进行传统的学术学习。

During intense exercise—sprinting, for example—your body breaks down glucose and produces what's called lactate.

在做短跑等高强度运动时，你的身体会分解葡萄糖并产生乳酸。

After intense exercise, you need to cool down your body to let your heart rate decrease naturally.

剧烈运动后，你需要给身体降温，让心率自然下降。

Another study found that mouthpiece use may increase performance and decrease stress when used during intense resistance exercise.

另一项研究发现，在进行激烈的阻力运动时，使用牙套可以提高表现，减少压力。

To " cool down" means to do easy exercises after doing an intense exercise.

“cool down”是指做完剧烈运动后做简单的运动。

CrossFit is an intense exercise program. It combines movements from several different sports and activities.

CrossFit 是一项激烈的锻炼计划。 它结合了几种不同运动和活动的动作。

But during intense exercise, you do not need to digest your food, so arteries to your digestive system will constrict.

但是在剧烈运动中，你不需要消化食物，所以通往消化系统的动脉会收缩。

The first being a 2017 study where subjects were trialed in either 0,15,30, or 45 minutes of intense aerobic exercise on a cycle ergometer.

第一项是2017年的研究，在这项研究中，受试者在一台自行车测力计上进行了0分钟、15分钟、30分钟或45分钟的剧烈有氧运动。

And if you can't do intense exercise, finding a partner to go on light walks with can also have positive effects on your health.

如果你无法进行高强度的锻炼，找一个伙伴一起轻松散步也能对健康产生积极影响。

On the one hand, young people are more energetic, so they will do some intense exercise like playing basketball and running.

一方面，年轻人精力充沛，会做一些剧烈的运动， 比如打篮球、跑步。

This is fine for normal, everyday activities such as gardening or taking kids to a park because most of those activities don't involve intense exercise.

这对于正常的日常活动来说是可以的，比如园艺或者带孩子去公园，因为这些活动大多不需要剧烈运动。

For example, during intense exercise, muscle cells will use up all of their oxygen and switch to a process called lactic acid fermentation, which uses glucose to produce energy.

举个例子，在激烈运动的过程中，肌肉细胞会耗尽它们的氧气并且转换到一个叫乳酸发酵的过程，就是用葡萄糖提供能量。

Data in 2016, however, by Howe and colleagues, did look into the impact on female subjects' appetite with intense exercise, this time with varying intensities of running on a treadmill.

然而，豪和同事在2016年的数据确实研究了高强度运动对女性受试者食欲的影响，这次是在跑步机上进行不同强度的跑步。

People who do twice this - two and a half hours of intense exercise a week - were shown to benefit slightly, further reducing the threat of death by between two and four percent.

研究表明，每周进行两个半小时剧烈运动（每周建议剧烈运动量的两倍）的人获得的益处更大一点，进一步将死亡风险降低了 2%至 4%。

This might have to do with the limited ability of tracking specific exercises, especially intense exercises that don't require much arm movement, like cycling, or exercise that don't require much distance traveled, like lifting weights.

这可能与跟踪特定运动的能力有限有关，尤其是不需要太多手臂运动的激烈运动，比如骑自行车，或者不需要走太远距离的运动，比如举重。