Once I started teaching, I began to realize that for new divers without a swimming background, the whole process of going to a community pool lap swim can be intimidating, and while they may have figured out that all top ocean and depth freedivers train to varying degrees in pools, the new diver may not be sure where to start.
Here's some tips, useful not only to freedivers who have no history of pool training, but also for freedivers who may be quite at home in a lap swim but looking for the best way to train specifically for ocean/depth diving in a swimming pool.
1) Don't even think about doing unsupervised static training or max attempts at a lap swim. A lifeguard does not count as 'supervision', only a trained buddy who is watching you and only you, and within arms reach of you (or closer) is 'supervision'.
Same goes for max distance attempts. It is not necessary or desirable to always train to failure in freediving. Some 'old-timers' did train this way (with proper safety present) but most modern freedivers practice a higher volume/lower intensity type training which is safer, less mentally exhausting, and more beneficial. We know it works because we've seen big jumps in freediving records within the last 15 years as divers began shifting to this training philosophy. Many top divers never even attempt 'max' swims outside of competition, or they perform max attempts and target swims only immediately before competition during the taper phase of their training.
Apnea training should always be done with a training buddy.
2) Do explore interval training. Instead of going to a pool and just doing X number of laps, break it up into timed intervals. All swim training is done this way, and it's closer to the way we actually freedive in the ocean. In an ocean environment, our energy output is constantly changing, and we mix aerobic activity (surface swimming for instance) with anaerobic activity (diving).
Most pools advertised as 'Olympic sized' are actually 25 yards long (a modern Olympic pool is actually 50 meters long). Interval swim workouts are usually written by number of repetitions, distance, time interval, and stroke. So for instance,
6 x 50 @ 1:30 crawl ('Six fifties crawl on the one thirty.')
would mean to repeat a 50 yard swim (2 laps in a 25 yard pool) six times, with a minute and a half between each start, swimming crawl stroke. So the total set would take 9 minutes to complete. It's worth noting the minute and a half interval is NOT the length of time to rest BETWEEN each 50 yards but the total time allotted for each 50. So if I finish the first 50 yard repetition in 45 seconds, I'd have 45 seconds to rest before I start the next one. Likewise if I spend 60 seconds on the swim, I'd have 30 seconds rest before the next one. For some freedive training I will use a different style interval but most of my training is done in this style. The clock keeps me honest, and by performing a large number of swims this way I can get a larger sample size for testing different styles, techniques, and pace variations.
Don't be afraid to add in sprints, even if you obviously don't dive that way in the ocean. It's beneficial to do some conditioning and training at a higher workload than your real world dive load. If I had time to spearfish for 6 hours... I'd be spearfishing for 6 hours! One of the best ways I found to build and maintain my stamina for long days in the ocean was intense pool training, lots of shorter swims (50M or less) with a short rest interval.
3) If you are a training for depth, spearfishing, or really anything but pool distance apnea (DYN or DNF), leave your wetsuit and weights at home. If you are wearing a wetsuit, you will not feel the water flowing on your skin, which means you will get less feedback on how effective and efficient your kick or stroke technique is. Same goes for weights. If you are pool training as conditioning for ocean, you should be swimming at a fast enough pace that you do not need weights to stay down (particularly if you aren't wearing a wetsuit).
If you have seen photos or videos of freedivers in full wetsuits and giant neck weights swimming slow in a pool, that's DYN or DNF. It's a whole different discipline than ocean, very impressive and very challenging, but the pace and equipment that works in that discipline is not realistic or safe for ocean diving, particularly depth.
4) Think about training WITHOUT longfins or a mono. Longfins and monofins are spectacularly efficient. That's why we like them for freediving--very little effort can generate significant propulsion. By the same token, if I have horrible habits and poor kicking technique, I can still propel myself in a pair of longfins, and unless I make a conscious effort to get better, I will continue using the same bad techniques and never reach my full potential. However, if I develop the skill to kick efficiently and effectively without fins, when I put on a pair of fins and gain the benefit of that extra surface area, I will be a class apart from other freedivers.
5) Follow the rules and conventions of the lap swim. At most lap swims, if there are only two swimmers in the lane, they may opt to 'split' the lane. Meaning each swimmer stays in their own half of the lane at all times. If there are more than two swimmers in the lane, then everyone will 'circle swim'. This means that each swimmer always stays to the right of the centerline, like driving on a road. If you are resting at the wall, don't park yourself in the middle. Move to one side so that the middle stays clear for other people to finish or make turns.
6) Do a warm-down. A lot of freedivers--even experienced competitors--skip this step. All you need to do for your warmdown is about 10 minutes of easy, aerobic activity, such as some relaxed surface swimming. This will get the blood flowing to the muscles, open up capillaries, flush out metabolic waste, and aid in muscle recovery. For apnea, warmdown is particularly important because while we want to experience vasoconstriction and dive response during our dives, dive response and any lingering effects are not good for building or maintaining muscles. Our muscles need blood flow and oxygen to recover.
That's it for now. I'll be posting more specific workouts in Pro-Tips section of this blog, but until then, here's some footage of pool swimming in long fins, including a slow motion breakdown of an effective longfin kick...