This is a hard questions to answer as different people react differently. However, if you asked me, I would say yes, but there are much better protein foods.
I have them straight after a session. For me they are most effective when I have more than one session a day so I can recover properly between sessions. I used to just have water after session, but my muscles were aching the next day, which meant I couldn’t train as hard. Although I only have protein shakes when I’m training away from home. Because when I’m training on the canal at home, the best thing you can have are eggs. High quality protein. Nothing artificial. I’m used to eating hard-boiled eggs as I eat around 3-4 every day to keep protein levels high. But remember that protein shakes and bars only work if you have it within 20 minutes of exercise as that is when your muscles can absorb it the fastest.
Lastly, where should you buy them from. This is the most important part, because some cheap ones can include traces of illegal substances. My favourite brand is SIS (Science In Sport), My Protein and SciMx. They are trusted by world bests athletes. They are a little bit more expensive than the ones you can buy in shops like Tesco and Home Bargains, but at least you know they are 100% safe to use. When do I need extra protein? You don’t need it after sessions where you are focusing on the technique as it’s not very intense, which will mean you don’t break any muscles fibres. Becuase the breaking of the micro muscle fibres is what causes the soreness and stiffness.
The bottom line is that they definitely work for me, or at least I believe it works. But just because it works for me, it doesn’t mean it will work for you.