"There's all different levels at my boot camps so it works really well. A lot were members of gyms before but they've now put them on hold.
"Some people find it hard to get motivated to go to the gym. They can get bored with the machines. But with boot camp there are other people waiting for you, which motivates you to come, and I'm giving instructions on what to do.
"I had one client who wanted to do personal training one-on-one with me but I thought it would be cheaper and more in keeping with her goals to do boot camp and that's worked out really well."
Miss O'Neill said the Bay's climate and beautiful surroundings were ideal for boot camp.
"I also give my clients meal plans and healthy eating advice because that's all part of it."
Joe Bourne, who works as a GP liaison for the Bay of Plenty District Health Board, recommended boot camps as long as people used them as part of a consistent exercise regime.
"Exercise which raises your breathing rate to a higher-than-normal state is good and my experience of boot camps is that they certainly do that.
"From a health-behaviour change perspective though, the most important thing is sustainability.
"Make sure you enjoy it. If you enjoy it, you're more likely to keep going. With a lot of boot camps, you get in with a group who go every time. That builds friendships and that group commitment is definitely helpful.
"It's like a diet. You don't want to do it for a short period and then go back to old habits. If you were to do boot camp for 10 weeks you would recognise the benefits during that time but, if you stop and go back to your old routine, you will quickly lose those benefits," Dr Bourne said.
"It's also important to remember that fitness is not just about exercise. It's about healthy eating and other factors."
John Templeton of Mount CrossFit said after popular television shows had used military instructors and training to approach fat loss, the idea had just taken off.
"Everybody knows the military is renowned for getting people into shape fast. I trained and served in the New Zealand Army as a physical training instructor and can safely say the training some boot camps offer can be little more than a mild fitness session."
Mr Templeton said the name "boot camp" could mean anything so people needed to be careful about what they were signing up for. "The term 'boot camp' is now thrown around by many trainers as a sales pitch that involves a basic fitness session instead of a well-planned period of intense training. If you want a good boot camp, ask questions and find out what experience the trainer has had in this environment - otherwise you may not get the results you are after."
Karen Clarkson attended Mr Templeton's boot camp last year for six months and said it was the perfect way to get active again after a cruisy summer. She said it was great to work out in a team environment and meet new people.
"Being military trained, the trainers knew how to get the best out of you, but not in a pushy, drill sergeant way. I definitely found the Mount CrossFit boot camp helped me lose inches and tone up, but not necessarily lose kilos. It also improved my fitness levels quickly."
Ms Clarkson said the best part was starting the day off early with a fun group of people.
"Its hard to drag yourself out of bed, but starting the day feeling refreshed and amazing is worth it. The atmosphere was great - it became like a family working out together. The trainers made a point of knowing our names and making us learn each other's."
Ms Clarkson said she would recommend a boot camp to others.
"Boot camps have their place, but it's not so much what you do at boot camps, it's what you commit to afterwards.
"Ultimately, the benefits come when you commit to a long-term exercise plan."
