Engine: row and ride

What happens

Forty-five minutes split between the rower and the bike, in long blocks of six to ten minutes. The target is Base: an effort you could hold a conversation through. The screens will tell you when you have crept too high, which is most people, most weeks.

Who it is for

Everyone, but especially the people who think easy training is a waste of time. This is the class that makes Thres intervals survivable and Max efforts repeatable.

What you will notice

• The same pace at a lower heart rate within a month.

• More in the tank for the hard days.

• A strange new fondness for the rowing machine.