It simply means that you should avoid exercising in hot conditions, avoid wearing too much clothing and control your intensitylevels.
这只是意味著你应该避免在热的环境中锻炼，避免穿太多的衣服，并且控制你的锻炼强度。
2
Typically the higher-intensitylevels range from 2-5 minutes in duration and are followed by lower-intensity periods that also range from 2-5 minutes.
通常情况下高强度的水平范围从2-5分钟的时间长短和其次是低强度的时期，也从2-5分钟。
3
The higher-intensitylevels can range from 2-15 minutes in duration and are followed by lower-intensity periods that also can range from 2-15 minutes in duration.