If you follow a few simple techniques in your training plan you can develop fitness faster.
Warm up = when warming up get the heart at 50% max heart rate for 5 minutes, this will increase the bodies output ready for the main session. Also increases the hearts ability to deal with fitness faster.
Main = Interval is the key for the main session, most important type of training that has been proven to increase cardio fitness immensely. Human bodies internal organs and muscles react faster to interval training. Easy to follow plans anyone can achieve, all you need is a watch and a boost of energy to complete your session.
You do need a basic to moderate fitness level to complete interval training, as it will increase pressure on your cardio output.
Interval training example,
Row for 2 minutes on level 7, 90% max heart rate
Then row for 3 minutes on level 10, 35% max heart rate
Repeat this method six times.
Total= 30 minutes
This plan can be used in most cardio exercise cycling, rowing , running or swimming.
If your a beginner to fitness consult a doctor before hand