Of course this tugging on the rope will also strengthen your arm muscles as you have to constantly fight to keep them bent so that you have control over your distance from the boat and aren’t just being dragged across the water. Tugging like this will specifically train your triceps which are the muscles on the backs of your arms. This is very important as the triceps should make up 2/3rds of our arms though most people neglect them and end up with bigger biceps and no triceps. At the same time, gripping onto the rope will help to strengthen your forearms and your grip which is highly useful for a range of tasks (it’s also worth bearing in mind that when you wear a t-shirt, the forearms are the only part of you that will be exposed and that you can thus show off your new found fitness. Finally the act of using the rope to pull yourself forwards will train your lats which are the muscles down your sides next to your arms often referred to as ‘wings’.