Fins and manoeuvrability

[scubadada]

Wow, this fin thread has certainly gone off in a bizarre direction.

There may be a relationship between the gut microbiome and body weight, but it's much more complex than what an adult chooses to eat. Come on Dan, you're eating a bunch of raw vegetables and have certainly cut down on your caloric intake, of course, you're going to lose weight.

Not all of us drink sugar drinks on the dive boat. I maintain a reasonable weight by consuming a reasonable diet every day and exercising to stay fit.

 

[mdb]

I think Dan has a pretty good point on fitness and diving. Yes the thread, one of many fin threads, started on maneuverability.

Seems that fitness is a big part of the equation.

 

[scubadada]

I think Dan has a pretty good point on fitness and diving. Yes the thread, one of many fin threads, started on maneuverability.

Seems that fitness is a big part of the equation.

I certainly do not disagree on fitness and diving. I also think watermanship, swimming ability, plays a very positive role. Many disagree on one or both of these points.

 

[tursiops]

You guys who live/dive on the edge of efficiency with your fins may like this link. The dolphins have it all figured out.
Dolphin-spring

 

[dmaziuk]

You need one of my DOL-Fins!

[video]https://youtu.be/Kr4vUrCWuXg[/video]

It keeps your body flat to eliminate the head bump.

Cool. But I see you don't kick with you back -- I do. In fact, bad disks are half the reason I took up swimming again, so when I do dolphin kicks in the pool I specifically try to work my back more. Which then translates into the head bump... can't win 'em all.

 

[danvolker]

You guys who live/dive on the edge of efficiency with your fins may like this link. The dolphins have it all figured out.
Dolphin-spring

Very interesting Article...thanks!

---------- Post added October 11th, 2015 at 02:17 PM ----------

Cool. But I see you don't kick with you back -- I do. In fact, bad disks are half the reason I took up swimming again, so when I do dolphin kicks in the pool I specifically try to work my back more. Which then translates into the head bump... can't win 'em all.

Ron's Dol-Fin kick actually does require lots of spinal oscillation, it is just hard to see it in the video....but to get the kick to be effective, it has your spine involved even more than your quads....However, it is a very low amplitude wave, so there is not a big visual showing it....the amplitude grows til it gets to the at the end of the feet at the wing, then becomes significant there. The coordination for this is nothing like using scuba or freedive fins....it is more like learning how to do a parallel turn in snow skiing....In that it is not a natural kicking movement, but the effective kick makes lots of sense, and when you do something right, you feel it immediately...Biofeedback is excellent.

---------- Post added October 11th, 2015 at 02:43 PM ----------

Wow, this fin thread has certainly gone off in a bizarre direction.

There may be a relationship between the gut microbiome and body weight, but it's much more complex than what an adult chooses to eat. Come on Dan, you're eating a bunch of raw vegetables and have certainly cut down on your caloric intake, of course, you're going to lose weight.

Not all of us drink sugar drinks on the dive boat. I maintain a reasonable weight by consuming a reasonable diet every day and exercising to stay fit.

I pretty much promised not to be harping on the gut bacteria or related aspects of the diet I'm on....but in response to your suggestion ....
Twice per day I eat 2 massive bowls of spinach, mixed greens, sunflower spouts, avocados, tomatoes....Bowls the size of serving bowls for a whole family
Calorically, it is high enough to allow excellent recovery from 3 to 4 bike rides each week, of 25 to 35 mile durations, with speeds at the level you expect from actively racing cyclists at cat 3 or better.
That should indicate that I am not on a low calorie diet...if I was, my muscles would not be replenishing glycogen, and muscle recovery would be failing---most likely I would be burning muscle tissue rather than building it.

Years ago, people used to say a calorie is a calorie. This has been proven conclusively to be incorrect, at least for people doing hard workouts.
Sugar calories create huge penalties for your body and metabolism, among the nastiest aside from insulin sensitivity, would be A.G.E. ( Advanced Glycation End Products) . A.G.E. causes inflammations in lining of blood vessels and on tendons and ligaments, and creates havoc in the intestine as well as the heart.

And as I said earlier, sugar can easily cause massive over-colonization of very bad bacteria in a human gut, and once you get this, it can be almost impossible to rid yourself of it, without some really extreme measures to restore the balance of flora you are supposed to have. Raw vegan is one way....Another I feel is a poor choice, utilizes strong and dangerous antibiotics that can kill off all the gut bacteria, both good and bad, leaving you to get busy rebuilding the correct flora from scratch.....along with many unintended consequences as well.

I know there are plenty of divers that are fit, and that do NOT drink sodas.
But I see the charter boats filling their coolers with Cokes, and that is what divers apparently want...statistically..or the coolers would be filled with a different beverage





****More on A.G.E. for those interested or that had not heard of it.

This is not related to gut flora, but rather to sugar being so bad for you, that a person that understands nutrition, can no longer say a sugar calorie is equal to a protein or fat calorie...In fact, the sugar calorie can undermine weight loss attempts or our attempts at bettering your health, in a way that fat or protein can NOT!

March 2014 Issue
Advanced Glycation End Products
By Lori Zanteson
Today’s Dietitian
Vol. 16 No. 3 P. 10
Studies show these harmful compounds may lead to insulin resistance and type 2 diabetes.
It’s well-known that overeating and obesity can lead to insulin resistance, triggered by chronically elevated oxidative stress and chronic inflammation. Recent evidence has found that excessive consumption of advanced glycation end products (AGEs), harmful compounds that stem from cooking foods at high temperatures and accumulate in the body as people age, are a major cause of this inflammation that can increase the risk of insulin resistance and type 2 diabetes.
Dietary interventions that reduce the consumption of foods high in AGEs, which are common in the standard Western diet, can be effective in helping prevent these metabolic disorders.
Understanding AGEs
AGEs naturally form inside the body when proteins or fats combine with sugars (glycation). This affects the normal function of cells, making them more susceptible to damage and premature aging. AGEs are particularly high in animal-derived foods that are high in fat and protein, such as meats (especially red meats), which are prone to AGE formation through cooking. Sugary foods and highly processed and prepackaged products also are high in AGEs. Cooking methods that use high temperatures to brown or char foods, such as grilling, roasting, and broiling, have the largest impact on the amount of AGEs consumed.
The body naturally rids itself of harmful AGE compounds, but it doesn’t eliminate them effectively when too many are ingested through food. All of the body’s cells are affected by the accumulation of AGEs, which not only have been linked to aging but also the development or worsening of many chronic illnesses, such as cardiovascular, liver, and Alzheimer’s diseases.
Dietary Intervention
To reduce AGE consumption, eating foods that contain low AGE levels is key to decreasing the risk of insulin resistance and type 2 diabetes. “We believe strongly that dietary restriction of AGEs are of tremendous importance,” says Jaime Uribarri, MD, a professor of medicine and nephrology at Mount Sinai School of Medicine in New York City, who’s conducted extensive research on AGEs and their effects on diabetes patients.
According to one study, published in the July 2011 issue of Diabetes Care, in which Uribarri was the lead author, AGE consumption may contribute to insulin resistance in type 2 diabetes, and restricting AGE foods may help preserve the body’s natural defenses against insulin resistance by preventing the development of oxidative stress. In the study, two groups of diabetes patients following the recommended standard of care for diabetes were randomized to either a high- or low-AGE diet. The results of the group who ate a low AGE diet “went far and beyond [those receiving] standard care. The AGE-restricted diet improved insulin resistance in those individuals. This is very impressive to us,” Uribarri says.
Another study coauthored by Uribarri, published in the January issue of Current Diabetes Reports, showed that because AGEs are associated with oxidative stress, they’re of particular concern to patients with diabetes and prediabetes. The researchers found that subjects who consumed a meal with a high AGE content had an increased circulation of AGEs in the body, and that lowering dietary AGE intake could improve hyperinsulinemia by about 40% in type 2 diabetes patients. Excessive intake of AGEs as a potential cause of diabetes is “an area of major clinical relevance,” the study concluded.
In research that’s under way and due to conclude in June, Uribarri is following a group of prediabetes patients with classic diabetes indicators, or metabolic risk factors, such as large waist circumference and hypertension, who are following a low-AGE diet for one year. He’s confident the results will support his previous findings that a low-AGE diet can play a role in preventing diabetes.
Modifying Cooking Methods
The most effective way to reduce intake of foods high in AGEs is to modify cooking methods. In a study published in the June 2010 issue of the Journal of the American Dietetic Association, Uribarri and colleagues developed a guide to AGE dietary reduction. The researchers found a link between heat-processed foods and AGEs. They compared different types of cooking methods and found that dry heat promoted AGE formation by more than 10- to 100-fold above uncooked foods in all food categories. Meats high in protein and fat were likely to form AGEs during cooking, while carbohydrate-rich foods such as fruits, vegetables, and whole grains maintained low AGE levels after cooking. Foods cooked with moist heat, shorter cooking times and lower temperatures, and acidic ingredients such as vinegar or lemon juice produced the least amount of AGEs.
A Danish study published in the January issue of Diabetes Care showed that overweight women who ate foods cooked at high temperatures had much higher biological markers of insulin resistance compared with those who ate foods prepared by boiling or steaming.
Pat Baird, MA, RD, FADA, a member of the advisory board of the AGE Foundation, an organization committed to educating the public about the harmful effects of AGEs, is optimistic about sharing the benefits of a low-AGE diet. “We produce AGEs in our body, and we’re also ingesting them. The good news is we can adjust it,” she says, adding that preparing foods in a slow cooker is another good option.
Insider Tips
Despite these recommendations, Baird knows that people will continue to grill their food, so she encourages them to do so less frequently. When they do grill, however, she suggests they use an acid-based marinade that contains lemon or other citrus fruit juices, or vinegar. Not only does the acidity reduce AGE levels, “it enhances the flavor of food and enhances the flavor of the spices,” she says. “The indication is color.”
Whether on the grill, in a skillet, or in the oven, browning or charring foods is an indication that AGEs are present. Baird also suggests cooking foods with medium heat for an extra minute or two instead of using high heat.
Because it can be a challenge for people to eat fewer convenience foods, such as packaged snacks and ready-to-eat meals, Baird says using slow cookers can help, especially in families that often are short on time. But the benefits go beyond time-saving convenience. According to Baird, less oil is needed in slow cookers, more nutrients are retained compared with many other cooking methods, and recipes tend to include more vegetables.
In fact, eating more vegetables and fruits is another way to reduce AGE consumption. Baird stresses the importance of dietary phytonutrients, which are found in the pigments of various colorful fruits and vegetables. One type of phytonutrient in particular, called iridoids, which are found in deeply colored blueberries, cranberries, and noni fruit, can lower AGEs in the body, she says.
Counseling Clients
Counseling patients about AGEs is straightforward, Baird says. Dietitians already recommend patients eat less sugar and fewer processed foods, which is what they should suggest to clients who need to lower their AGE intake.
In addition, people who are sleep deprived have higher circulating AGEs, Baird says. Sleep is the time when the body does most of its tissue growth and repair, making it better able to defend itself against AGEs. Sleep, daily activity, and stress reduction play important roles, along with diet, to reduce AGEs.
While most dietitians understand this, Baird says, the new research may not be so familiar. The AGE Foundation website (http://agefoundation.com) is an ideal source to bring dietitians up-to-date on the most current research, complete with background information, resources, and FAQs. There’s even information on AGE scanners that use LED light to penetrate the skin and measure AGE levels. According to Baird, this technology, which currently is being tested in clinical trials, may one day be a useful noninvasive tool for dietitians to use.
Uribarri and Baird look forward to dietitians becoming more familiar with the topic of AGEs. “They should be the first to embark on this chain,” Uribarri says. Patients with prediabetes and diabetes may benefit from the healthful lifestyle of a low AGE diet.
— Lori Zanteson is a food, nutrition, and health writer based in southern California.

Tips for Lowering AGE Consumption
Foods High in AGEs
• Sugary items such as candy, cookies, cakes, soda, and pastries
• Processed foods, including packaged meats and cheese
• High-fat (especially red) meats
• Fats, including butter, margarine, and oil
• Fried foods
Foods Low in AGEs
• Fruits and vegetables
• Seafood
• Whole grains
• Low-fat breads
• Pasta
• Vegetarian burgers
Cooking Methods
• Use a slow cooker
• Cook foods in water through boiling, steaming, or poaching
• Marinate foods in acidic or citrus-based sauces
Healthful Lifestyle Changes
• Get the recommended seven to nine hours of sleep per night
• Exercise 150 minutes per week
• Treat preexisting conditions such as obesity and high blood pressure
— Source: AGE Foundation

 

[guyharrisonphoto]

My force fin experience.

I finally got the chance to dive the Force Fins Exellerating Fin that Dan loaned to me. These are very different from regular Force Fins so this experience might not translate to those. Like Dan, I believe fins are very underrated in importance for diving comfort and even safety. I would not hesitate to spend $400 on a pair of fins if I thought they would give me a substantial benefit in comfort, power or maneuverability.

The dive was on the Spiegel Grove, depth multi-level 100 to 65’. Dive time 38 mins on the bottom. Vis 60’, current was light. Wore them with 3mm soft booties.I compared them to my Cressi Master Frogs, which I dove on the next dive, The Benwood, depth 40’, dive time 60 minutes, current: none. Wore them with 5mm hard sole booties.

Going in to this, I consider the Master Frogs to be the finest all-around scuba fins on the market, with strong power and acceleration with a hard flutter kick and great in currents, very low effort cruising with a flutter or modified flutter, good dolphin kicking due to the relatively large blade, excellent frog kicking and helicopter turning due to the flat blade with no frills, humps or side ridges, and very good backward kicking. They are light, only slightly negative in the water (neutral for all practical purposes). They do it all, and do it all really well.

Fit: What is really unique about the Force Fin, even more than the blade, is the foot pocket design. “Pocket” is not really the right word as the front of the foot is not enclosed. No cramping of the toes or foot at all. The pressure of the down-stroke is on the top of the foot, where the arch of hard rubber is. The upstroke is on the sole, which is very rigid. There is no pressure on the toes or on the arch of the foot. Thus, no need for hard sole booties. No need for any booties at all, really, but I wore soft ones for protection. I can’t imagine getting arch cramps with these even with hard kicking. Also, very easy to get on and off.

The Cressis are traditional foot pocket fins, where you need hard booties for full support and power, and the foot is crammed into the pocket by the force of the strap. Toes can be a little cramped. The force of the swim stroke flexes the foot so you need hard sole booties to mitigate arch cramps and give fill power to the stroke.

As for fit and comfort, the Force Fin is significantly better.

Materials. The Cressi blade is a thin plastic composite material taken from their freediving fin. Very light and lots of “snap.” The blade is large, for a lot of area to push water. The Force Fin is a thick type of rubber. Lots of “snap” in the first third of the blade, transitioning to complete stiffness at the sole of the foot. Blade area is smaller than the Cressi. Also has “wings” on the top that are designed for force water onto the blade surface during the down-stroke, thus increasing the power. CAUTION: Whatever rubber Force Fin uses has no gripping power on a flat surface. These fins are VERY SLIPPERY on a boat deck. I almost slipped when taking a single step to the platform. On one trip, on a different boat, Dan slipped and actually fell when geared up while trying to walk to the platform. This is not a good thing. The Cressi had no such problem.

Flutter kicking. The real test, of course, is how they swim. The Force Fin flutter kicks superbly. I was very impressed with how much power it gave for the size of its blade. Equal to the Cressi in my view. The big difference is not so much power but comfort while kicking. No toe or arch stress. You feel the downstroke pressure over the top of the foot, without flexing of the foot. Very nice, indeed. Definitely more comfortable than the Cressi or, I would say, any other traditional foot pocket design. It does require a different technique. The Force Fin has, basically, little power on the “upstroke.” The real power is on the downstroke. The up-curved shape makes the upstroke quick and easy, not intending to have power in both directions. When you snap it down hard, it really shoots you forward. Thus, you need to get the fin up high, and then power kick down, letting the blade wings and “snap” do the rest. I tried a traditional freedive-type kick (stiff leg kicking from the hip—equal power both directions) and that did not work so well. So, I tried flexing more from the knees, letting the quads pull down in a more snap type kick, and then bending at the knee to easily move the fin to the up position without trying for much power on the upstroke. That worked really well. My impression was that the power of the fin and its comfort (and not using the large leg and hip muscles so much) made it very efficient. Certainly, my air consumption was really good on the dive.

The Cressi calls for the freedive kick as above, because the fin gives you “snap” in both up and down stroke, so you want the power equal for each. Kicking this way really cranks out the power of this fin. However, I think you use more energy this way and it is more stress on the foot.For flutter kicking, the Force Fin really has something special going.

Other Kicks. I found the frog kick to be noticeably weaker than what I get from my Cressi. The slim blade and upward curve of the Force Fin made it difficult for me to find an optimum stroke. It was not nearly as powerful as what I got from the Cressi. Same with helicopter turns, had a hard time making the fin “grab” the water to turn. For backwards kicking, they were great. The upward turned blade really grabbed water. Best back-kicking fin I have used, but the Cressis, again, were pretty close. My initial conclusion is that I want more practice using the FF with frog and helicopter kicks. Just did not have enough time on the wreck to do those. I would like to take them on my favorite beach dive, with a long flutter and dolphin kicking swim to the reef, and then a couple of hours exclusively doing frog, helicopter and back kicks for macro photo. Also, advice on these kicks from Dan or Bob Evans would be useful.

Overall, for divers who mostly flutter kick (which is many, maybe most, reef and shore cruisers), or who need to deal with current and want a compact fin (i.e. no freedive fins), and any diver who does not like cramped toes or cramps in the arch of their foot, the exellerating FFs are superb and should be on anyone’s list. However, the fact that you can’t return them if they do not suit you, along with their considerable price tag, makes it hard to just go out and get a pair.For divers doing a lot of other kick styles, I would have to say you can make them work but they are not optimal—but I would want more practice on technique than I got in a 40 minute dive.

For me, I often, in a single dive, have to deal with current getting to and around a deep wreck or do a long shore swim to a reef, and then delicately frog, backward, and helicopter kick for my photography. I do lots of kick styles, all the time. For now, the Cressis are remaining in my dive bag as the FFs did not persuade me they were a better all-around fin despite their superior comfort. If I want an ultimate power fin for flutter or dolphin kicking for my strong current reef and wreck dives, which is where the FFs excel, and the cost is $400, I would get a pair of carbon fiber (or DiveR) freedive fins, which will be even more powerful than the FFs for those particular conditions.

I will update this if I have the chance to work more on the frog and helicopter kicks.

 

[scubadada]

Thanks Guy, I hope to try Dan's fins in November, on my next visit to FL

 

[guyharrisonphoto]

When you get down let me know and we can get out for a dive.

 

[guyharrisonphoto]

Before I start, I can’t thank Dan Volker enough for allowing me to hang on to his Force Fins until I could get these experiments done.

I got to take the Force Fins on my favorite shore dive at Lauderdale by the Sea. Again the comparison is to the Cressi Master Frog, as discussed in my prior post. This is a 250 yard swim each way to and from the reef, then just tooling around north and south on the reef. There is a lot of macro work, and also schools of fish to chase. Depth is shallow (20’max) so we got a bottom time of 100 minutes. Less time than usual due to the effort of switching fins underwater a couple of times and some intentional hard kicking, but this, finally, would be the all-around workout that I wanted to give the fins.

This time, swapped the fins out underwater during the dive so got a really good, immediate comparison. The kicking was strong flutter to and from the reef. Modified flutter along the reef with some interludes of strong flutter to chase bait balls. Lots of frog kicking when searching for macro, and lots of helicopter when shooting. Some backwards kicking, and I intentionally did some backwards kicking just for practice and to compare the two fins side by side. I was in full gear with my camera rig, AL 80, 3 mil suit, 11 pounds of weight including my backplate, 40lb wing.

First I’ll talk about the fin “tech.” The FF is represented as a highly sophisticated hydrodynamic design. The blade starts narrow at the foot pocket for a ways, and then flares out wide with a slight “V” at the end similar to a fish’s tale. There are “whiskers” that funnel water onto the wide blade area, increasing the force of the stroke. The material is basic rubber (did not get to try the “Tan Delta” material) and the heel strap is basic. There is “snap” mainly in the widened area, moderate at the tip but rapidly getting very stiff. They are fairly small in surface area due to their narrow width along some of their length, and overall average length. Their dynamics are supposed to create great power for the size.

The Cressi is a traditional foot pocket design. The blade extends under the foot pocket for a ways, and is wide and gets wider fast after the end of the foot pocket. It has a square end. Very much a typical basic paddle blade shape. The blade is flat and very thin, no holes, vents, ridges, whiskers, wings, splits, bungees to change stiffness or other brouhaha. There are very small ridges that extend about halfway down the blade (to hold it in the foot pocket), with the rest just being the thin exposed edge of the blade. The “tech” is in the blade material and design. The material is the plastic composite used in their freedive fins. The size is adjusted for scuba, with the fin being shorter, but also wider, than the freedive fin. The “snap” of the material is adjusted for the changed shape (this is not a shortened freedive fin with the softer tip removed). The tip area is fairly soft with a delicate snap, which gets more vigorous towards the foot pocket. They are substantially larger in area than the FF.

1. Strong swimming over a long distance. The FFs have power for their size, this was re-confirmed from my previous test. Now, though, I conclude that the Cressis have more power on a strong kick. There is just no substitute for larger fin area and a thin, snappy blade of high-tech freedive fin material that snaps on both the up and down stroke. On the swim out with the FF, my feet got sore, especially over the top of the foot where the force of the kick meets the fin. There is also some flex to the sole so the bottom of the foot feels the pressure as well. Some soreness in my thigh muscles too. We were really cranking so this was a good test. On the plus side, no crammed toes or squeezing on the sides of the foot. But, with this hard test, I just felt I was moving easier with the Cressis when pushing hard for a long time.

2. Modified Flutter. For a slower trip down the reef with an easier modified flutter kick the FFs were great. Their small size was very nice and the comfort advantage was real. I tended to forget they were there. The Cressis moved me faster with the same effort, but the difference was not great and a lot less foot comfort. I call it advantage to the FFs.

3. Frog Kick. With practice, you can get a good frog kick from the FFs (the exellerating model, remember). But, it requires focus and precise technique. The blades start very thin across at the foot pocket, and then widen only towards the tip, so not much surface area to catch water. The tips curl slightly upward and do not “snap” in the direction of a frog kick (which is basically like an upstroke-the FFs have a one directional bias to their snap, but in the down direction). Due to this, the blades must be perfectly sideways with the edges straight and down, and snapped together hard. Any off-perpendicular angle to the blade and you lose a lot of the force. Also, the blades are thick, so they do not sideslip well and you really do not “feel” where they are. The Cressis sideslip effortlessly and you always know where they are because they give immediate feedback of which way they are pushing water. It is hard to describe it more precisely than that. I found it irritating to have to concentrate so much on each kick with the FF. The Cressis, by contrast, can deliver a nice push even if the blades are not perfectly perpendicular due to the large, flat blade that “snaps” in both directions, and I do not have to focus, at all, on technique as the Cressis allow a lot of slop. Does this make me lazy? YES. I don’t even have to think when frog kicking the Cressis.

4. Helicopter turns. This is essential for my photo work. Again, clear advantage to the Cressis. You have to contort your body to get the FFs a little sideways so that the upward turned blade scoops water sideways. I never could find a comfortable way to do this. The really wide blade of the Cressi, with its soft flex right at the tip, meant that just a tiny tilt of the fin with a light scull spins me like a top or with great precision, my choice with no thought. No contest, here.

5. Back Kick. On the wreck dive, I thought the FFs were super good, but I only tried one or two back kicks. I did a bunch on the reef and have changed my mind. Again, you have to position the upturned blade very precisely each kick, so it scoops water backwards. Any error in the angle and it does not really go. I tried a 30 foot back kick stretch. The Cressis did fine. The FFs lost it after a few strokes if I lost the angle, and then I had to build momentum again. I really don’t think the FFs are better, after all, and might actually be harder.

After this, which is 2 ½ hours in the water between both dives, my conclusion is that the Master Frog is a distinctly better all-around fin than the Force Fin, for every kick except a moderate modified flutter. This is due, I believe, to the larger surface area, and thin, flat snappy blade of the Cressis. The hydrodynamic sophistication of the Force Fin (which I take for granted is real due to the power for its size) does not make up the difference..

And then, there is the price (and I am not cheap about good gear if it works). For the price of the FFs I could get my Master Frogs and FIVE yes, FIVE, two tank boat trips to my favorite reefs and wrecks, and that is for the regular $400 rubber material (no whiskers included) not the $650 tan delta material. No contest there, either.