Dry Land Training for Ice Speed

Although hockey season in not quite here yet, dry land training season is. Many young players are taking part in strength and speed training clinics in order that they may perform better on the ice come September. You will see them outside on the fields using agility ladders, step hurdles and even speed chutes to improve their performance on the ice. Experts suggest that dry land training for hockey players should start when the player hits the 12 to 14 year age group. This is when they can benefit the most from a fitness regime both on and off the ice. It will not only improve their ice speed but also help them to develop a harder shot.

Anaerobic endurance is one of the benefits of dry land training. This can be done by including running, jogging, cycling or skipping in your workout. But one of the most effective benefits of dry land training would be for power, strength and speed. These would be exercises that focus on the legs and core, such as sprints, squats, lunges and any abdominal exercises such as sit ups. To increase an athlete’s power resistance training is also important, as well as exercises such as the jump squat.

SIRC has lots of resources on dry land training as well as drills specifically suited for hockey. So before you strap on those skates for the hockey season, strap on those cross trainers and get outside and run, sprint, squat, lunge and jump and before you know it you will be the fastest player on the ice.

• Jumping into plyometrics: 100 exercises for power & strength. Chu, Donald A. Human Kinetics, 1998.
• THE SECRETS TO EUROPEAN DRY-LAND WORK. DIXON, RYAN, Hockey News 2009 Special Issue, p7
• Training for high-performance collegiate ice hockey. / Entrainement pour la haute performance en hockey sur glace universitaire. Hedrick, A., Strength & Conditioning Journal Apr 2002: Vol. 24 Issue 2. p. 42-52
• Ice hockey/roller hockey: in-season resistance training. Penn State Sports Medicine Newsletter Dec 1998: Vol. 7 Issue 4. p. 2
• Intensive Hockey Camps establish new training benchmark. Hockey News 2/7/2006, Vol. 59 Issue 20, pHS41

Cross Trainers?

We all know how important it is to have proper fitting footwear for our sporting endeavors. But did you ever think that you’d be wearing shoes in the pool? American Olympic swimmer Amanda Weir has been using running shoes in her pool training to help improve her lower body strength for kicking. According to her coach, shoes are a great form of resistance training; they add a strain on the swimmer’s legs that forces them to develop more powerful muscles and better endurance. Kicking with shoes means that swimmers can retain a full range of movement so they develop strength alongside ankle flexibility. There also seems to be a mental or perceptual benefit to training with shoes in that when they come off, the feet feel lighter and faster, and have a better grip on the water.

So next time you are looking to throw a little change into your swimming routine, pack your shoes and try it out.

Reference from the SIRC Collection: Savage Hays, Kelsey (2010). If the Shoe Fits… Splash, 18(3), 32-33.

Does exercise help osteoarthritis?

Osteoarthritis or "common arthritis" is the gradual wearing down of the joint's hyaline cartilage. Our joint's have a shiny, smooth surface at the end of each bone which allows friction and free motion. When this area becomes damaged, thinned or worn away it is known as osteoarthritis. The rubbing of the damaged area is painful and the repetition leads to inflammation, swelling and more pain.

Three kinds of exercises you can do if you have osteoarthritis:

• exercises involving range of motion, also called flexibility exercises
• endurance or aerobic exercises such as swimming
• strengthening exercises such as lifting small weights or resistance band training

Exercise is considered the most effective non-drug treatment for reducing pain and improving movement for people with osteoarthritis.  Keep in mind that exercise should be balanced with rest and joint care. If your joints hurt or you have redness or swelling, rest your joints and then try again.  Other treatments include physiotherapy, podiatry, anti-inflammatories and supplements such as Glucosamine and Chondroitin.  These supplements are not heavily researched, however they are still widely prescribed to help people with osteoarthritis.

You may not be able to perform like you did when your were in your twenties, but the smart person who continues to exercise is one who adapts their training and works with their body, not against it.  As always, before starting any training regimen, speak to your doctor first and then decide which exercises may be best for you.  Many people have made changes to their lifestyle after being diagnosed with osteoarthritis and continue to enjoy daily exercise.

References from the SIRC Collection: 

1. Better adherence to exercise means better relief from osteoarthritis pain. Research Review (International Council On Active Aging). July 28, 2010;10(27):2-3.
2. Christensen K. Ease the Pain of Arthritis With Exercise. American Fitness. July 2009;27(4):12-13. 
Exercises in Warm Water Can Help Relieve Osteoarthritis Pain. PT: Magazine Of Physical Therapy. January 2008;16(1):66-68.
3. Focht B. How Knee Osteoarthritis Patients Can Use Exercise to Enhance Quality of Life. ACSM's Health & Fitness Journal. September 2012;16(5):24-28.
4. Page P. Knee osteoarthritis: strength training for pain relief and functional improvement. Functional U. September 2003;1(6):1-6.
5. People with osteoarthritis feel better with exercise and the right shoes. Research Review (International Council On Active Aging). March 24, 2010;10(12):2-3.

Does protein aid recovery?

In recent years, post-exercise nutrition has evolved into an important part of an athlete's training regimen. Athletes of all ages, abilities and skill levels are commonly adopting some sort of post-exercise nutrition to improve performance and enhance the recovery process.  Endurance athletes know that carbohydrates are essential for recovery, but what they may not know is that combining it with protein may have some additional benefits.

While protein and carbohydrates have their own distinct functions, together they work to create an anabolic state within the body that can help athletes recover faster.

Recent studies have shown that:

• Ingestion of small amounts of dietary protein 5 or 6 times daily might support muscle protein synthesis throughout the day.
• Consuming post-exercise carbohydrate and protein within 30 minutes of exercise has been shown to increase the insulin response in the body resulting in more stored glycogen.
• Recovery significantly improved four hours after intense exercise when an athlete consumed a protein and carbohydrate drink.
• A 3:1 or 4:1 ratio of carbohydrate and protein is optimal (three-four grams of carbohydrate for every one gram of protein).
• Protein and carbohydrate consumption may be of particular benefit to athletes who are involved in multiple training or competition sessions.

Athletes should be able to get the required amount of protein for their needs by talking to a registered dietitian and altering their diets to match their training. Some good examples of protein to add to your diet are: milk, cheese, eggs, meat, fish, assorted beans, peas lentils and grains. 

Achieving a balance between training, competition stresses and recovery is very important for the success of any athlete. Post-exercise nutrition is an essential part of any training program and consuming the proper nutrients after extensive training kick starts the restoration of muscle glycogen and initiates the recovery process.

References from the SIRC Collection: 

1. Beelen M, Burke L, Gibaia M, Van Loon L. Nutritional Strategies to Promote Postexercise Recovery. International Journal Of Sport Nutrition & Exercise Metabolism. December 2010;20(6):515-532.
2. Cepero M, Padial R, Rojas F, Geerlings A, De la Cruz J, Boza J. INFLUENCE OF INGESTING CASEIN PROTEIN AND WHEY PROTEIN CARBOHYDRATE BEVERAGES ON RECOVERY AND PERFORMANCE OF AN ENDURANCE CYCLING TEST. Journal Of Human Sport & Exercise. July 2010;5(2):158-175.
3. Coyle C, Donne B, Mahony N. Effects of Carbohydrate-Protein Ingestion Post-Resistance Training in Male Rugby Players. International Journal Of Exercise Science. January 2012;5(1):39-49. 
4. PROTEIN MISCONCEPTIONS: Details on misconceptions regarding protein supplementation-and where they come from. Journal Of Pure Power. January 2009;4(1):48-52.
5. Res P, Groen B, Van Loon L, et al. Protein Ingestion before Sleep Improves Postexercise Overnight Recovery. Medicine & Science In Sports & Exercise. August 2012;44(8):1560-1569.
6. Williams M. Protein Supplementation and Endurance Exercise. Marathon & Beyond. November 2012;16(6):172-173.

Exercise and bone health

It is well known that regular exercise is excellent for your heart, health and well-being. There is also plenty of evidence that proves that regular exercise is essential in warding off various health-related issues; what's not as well known is that people who perform non-weight bearing exercises such as cycling or swimming as their sole method of exercise could be putting themselves at risk for osteoporosis.

 
Bone is living tissue that responds to loads placed on it. If you perform  non-weight bearing exercises your bones won't retain their density like they would with a weight bearing exercise. If cycling or swimming is currently your only form of exercise, you can be proactive in preventing the disease by adding a little variation in your training.

• Weight bearing exercises such as walking, running, skiing, dancing or jumping all help to retain bone density
• Cross training
• Resistance or weight training
• Improving core strength
• A diet that meets your calcium and vitamin D requirements

A common misconception is that osteoporosis is a disease that is limited to aging women since low estrogen causes bone deterioration, in fact it can affect men as well. Care should be taken for young people in particular, since bones keep growing and do not reach peak density until the age of 30.

For those of you that have already been diagnosed with osteoporosis, it doesn't mean you have to stop moving. Instead, perform exercises that strengthen the back, core and hip, and ensure that you supplement your routine with alternate workouts. Before you run out and buy calcium supplements or change your training schedule, it is always a good idea to talk to your doctor for their recommendations first.

References from the SIRC Collection: 

1. Campion F, NeviII A, MedeIIi J, et al. Bone Status in Professional Cyclists. International Journal Of Sports Medicine. July 2010;31(7):511-515.
2. Cedaro R. Osteroprorosis And Cycling. Triathlon & Multi Sport Magazine. July 2, 2012;15(7):76-78.
3. CYCLISTS AT RISK FOR OSTEOPOROSIS. IDEA Fitness Journal. July 2009;6(7):12.
4. Giles M. Bone strength matters. Bicycling Australia. May 2006;(139):52-54.
5. Hamilton A. Cycling health: a bone of contention. Cycling Weekly. September 30, 2010;:50-51.
6. Hawkins K. Cycling: Bad for the Bones?. Bicycle Paper. August 2012;41(6):1-5.
7. Nichols J, Rauh M. LONGITUDINAL CHANGES IN BONE MINERAL DENSITY IN MALE MASTER CYCLISTS AND NONATHLETES. Journal Of Strength & Conditioning Research (Lippincott Williams & Wilkins). March 2011;25(3):727-734.

Resistance Training for Endurance Runners

For many of us who enjoy distance running, we know that in order to improve, you have to get out and run. You have to get in your two or three workouts a week and add a long run for good measure. Though there is no substitution for running, you can supplement your training by incorporating resistance training. Resistance training will not improve your VO2 max or running economy but it will help improve other facets of your running, including your efficiency, ability to maintain proper form and minimizing muscle imbalances.

Being a distance runner, you want to be lean but you also want to be strong when finishing a race or when attacking a hill during a race. This means you want to target muscles that are related to running.

Here are a few resistance training routines you might want to incorporate to supplement your running:

• Plyometric – Hopping, jumping and bounding. While doing these exercises you should use a soft surface, preferably done before your workout while using proper technique and having minimal ground contact.

• Lower Body Resistance Training – Squats, calf raises and lunges exercises can be done before or after workouts, but allow ample time between resistance training and running workouts. These exercises work on your hamstrings, calves, gluteus, quadriceps and inner and outer thigh, which minimize imbalances making a difference in preventing injury.

• Hill Training – Unlike other resistance training routines, hills can help running economy. Use a hill with a gradual incline as opposed to a steep incline. A gradual incline helps maintain proper running form while building strength, speed and endurance. Hills can be done before or after the workout, or constitute the entire workout. 

Resistance training can also help improve running form by strengthening your core and preventing injuries when done properly. Strengthening your core will help in the latter parts of your race as you fatigue allowing you to maintain proper running form. Since running is such a repetitive sport, it can create muscle imbalances, which can lead to injuries and interrupted training. 

When embarking on resistance training, you should ideally incorporate it before or after your workout on your hard days of training. The idea is to make your hard days hard and your easy days easy to allow you to recover properly.

References from the SIRC Collection:

1. Anderson O. Core curriculum. Runner's World. August 1997;32(8):38. 
2. Burgess T, Lambert M. The effects of training, muscle damage and fatigue on running economy. International Sportmed Journal. December 2010;11(4):363-379. 
3. Debnam M. Plyometrics: Training for Power. Modern Athlete & Coach. October 2007;45(4):5-7.

4. Jones P, Bampouras T. Resistance Training for Distance Running: A Brief Update. Strength & Conditioning Journal (Allen Press). February 2007;29(1):28-35. 

5. Jung A. The impact of resistance training on distance running performance. / L ' impact de l ' entrainement de resistance sur la performance en course de fond. Sports Medicine. 2003;33(7):539-552. 

6. Mikkola J, Vesterinen V, Taipale R, Capostagno B, Häkkinen K, Nummela A. Effect of resistance training regimens on treadmill running and neuromuscular performance in recreational endurance runners. Journal Of Sports Sciences. October 15, 2011;29(13):1359-1371.

7. Tanaka H, Swensen T. Impact of resistance training on endurance performance: a new form of cross-training?. Sports Medicine. March 1998;25(3):191-200.

The view is better at the top of the hill

Walter Payton, nicknamed Sweetness, was one of the greatest running backs to ever play the game of football. During his off-season conditioning he used to run up a hill simply dubbed “The Hill.” The Hill was about 50 to 60 yards with a very steep incline described by Walter as “a goal setter or a will maker”. During his 13-year National Football League (NFL) career, he was a two time MVP and a member of the 1985 Chicago Bears Super Bowl winning team. By the time he retired, he was the all time rushing record holder with 16,726 yards including the single game rushing record of 275 yards.

Hill running should be in the repertoire of all athletes who want to build strength, speed, and endurance. Not only do hills improve your running economy, they are an excellent form of resistance training, which can strengthen your hips and legs.

A recent study from Auckland University of Technology found that after 6 weeks of hill training, runners improved their 5km times by about 2%. For an individual who runs an eighteen-minute 5km, they can improve their time by about 21 seconds simply by adding hills to their training once or twice a week.

When attacking a hill, make sure you have high knee lift, shorten your stride and always look up, not down, at your legs.

When deciding to do hill training, you should consider the type of hill you are running and what the purpose of each hill is. 

• Short sprint hills take about 15 to 30 seconds. The idea in running short hills is to power your way to the top, making sure you have proper technique and working on your speed. Short sprint hills work more on the anaerobic system.
• Medium hills take between 30 and 90 seconds to run and work both the aerobic and anaerobic systems. The purpose of a medium hill is to train your body to tolerate lactic acid build up while maintaining both form and pace.
• Long hills usually take you about 90 seconds or longer and mostly benefit the aerobic system. The purpose of these hills is to build stamina, improve running economy and develop mental toughness.

Running over rolling, hilly terrain is a great way to encompass all three forms of hills mentioned above. Rolling hills are a perfect way to introduce your body to running hills. Using hilly ground mimics road racing or cross country racing.

The 1968 Mexico Olympics 1500 meters gold medalist Kip Keino described hill workouts as “very important before we started doing track workouts.” Hill training improves your running economy, incorporates resistance training and for most it builds mental toughness. Any athlete who aspires to be great should consider hill training as part of their regular training or off-season conditioning, as even the greatest athletes understand hill training builds speed, strength and endurance.

References from the SIRC Collection: 

1. Just for the hill of it. Running & Fitnews. November 2002;20(9):3. 

2. Kauppinen T. Why Every Football Player Should Be Put on Hill Sprints. Coach & Athletic Director. September 2007;77(2):40-41. 

3. Laurendet P. Hill Training. Modern Athlete & Coach. October 2010;48(4):31-32. 

4. Lieberman B. HILL WORK AN EQUINE BODYBUILDING SECRET. Equus. July 2009;(382):42-47. 

5. Mueller G. ASK THE COACH: BIKE TRAINING. Triathlon Life. Spring2012 2012;15(2):28-29. 

6. Running Hills, Options and Benefits Abound. Running & Fitnews. May 2009;27(3):5-6.

7. Russ M. HIT THE HILLS FOR A TRAINING BOOST. Triathlon Life. Spring2011 2011;14(2):34-35. 

Response and adaptation to training and exercise

When getting back to the grind after a good break from a long season, or when at the beginning of a new training or exercise routine, the body usually feels sore. For seasoned veterans, early season training feels very challenging; lets face it, getting back into shape can feel like a daunting task. For those trying a new training regime or a new sport, the new movements will leave you a little sore. This soreness is called delayed onset muscle soreness, DOMS. However as you continue to exercise, the body will respond and begin to adapt to the different stimulus, allowing you to increase intensity and be more efficient.

As your body is introduced to a new stimulus or reintroduced to a stimulus, damage occurs to muscle fibers. These small tears may be what causes the decrease in muscle function, tenderness and swelling in certain areas felt 8 to 72 hours after exercise. There is no need to worry. As the muscle fibers begin to repair themselves, you will be able to handle the workload much better. Your body will respond and begin to adapt to the training or activity.

The ability of the body to respond to a new stimulus and adapt to these demands is what allows us to exercise and improve fitness. There are two kinds of responses to physical exercise or training:

1. Acute response is an immediate response to exercise, lasting for the duration of the exercise or training session. This could include changes in the cardiovascular, respiratory and muscular systems depending on the intensity and duration. 
2. Chronic adaptation refers to long term changes, over 6 or more weeks, that occur during exercise and can include improved cardiovascular adaptation, respiratory adaptation, muscle tissue adaptation to aerobic training, cardiac hypertrophy, muscular hypertrophy and increased muscle stores.

Some people quit the activity due to the pain and soreness that occurs hours after exercising. The feeling of soreness is only temporary and, after a few days of recovery before going back to the activity, the muscles will be more resilient and less damage will occur. As you continue to exercise, the muscles will adapt to the stress; this is known as repeated bout effect. Essentially for the soreness to go away and for you to get any long-term benefits from your exercise, the exercise has to be repeated over and over again. If you decided to play basketball once every three weeks as opposed to once every three days, every time you play you are most likely to feel sore. Thus playing every three days allows you to adapt and improve fitness steadily.

Every acute response and chronic adaptation reaction depends on the stimulus you put your body through. Your body will respond differently to activities such as running and cycling (endurance training) than it will from lifting weights or resistance training. Soreness after the first day is usually a sign of DOMS and with good recovery you should be able to do the same movements in a few days with less pain. In the long term you should be able to increase intensity and duration as the body responds and adapts.


References from the SIRC Collection:

1. Carpinelli R. DOES THE SEQUENCE OF EXERCISE IN A RESISTANCE TRAINING SESSION AFFECT STRENGTH GAINS AND MUSCULAR HYPERTROPHY? A CRITICAL EXAMINATION OF THE EVIDENCE. Medicina Sportiva. April 2013;17(1):40-53.

2. de Salles B, Simão R, Miranda F, da Silva Novaes J, Lemos A, Willardson J. Rest Interval between Sets in Strength Training. Sports Medicine. September 2009;39(9):765-777.

3. Fernandez-Gonzalo R, Bresciani G, de Paz J, et al. Effects of a 4-week eccentric training program on the repeated bout effect in young active women. Journal Of Sports Science & Medicine. December 2011;10(4):692-699.

4. Hawley J. Adaptations Of Skeletal Muscle To Prolonged, Intense Endurance Training. Clinical & Experimental Pharmacology & Physiology [serial online]. March 2002;29(3):218-222.

5. Olsen O, Sjøhaug M, van Beekvelt M, Mork P. The Effect of Warm-Up and Cool-Down Exercise on Delayed Onset Muscle Soreness in the Quadriceps Muscle: a Randomized Controlled Trial. Journal Of Human Kinetics. December 2012;35:59-68.

6. Starbuck C, Eston R. Exercise-induced muscle damage and the repeated bout effect: evidence for cross transfer. European Journal Of Applied Physiology. March 2012;112(3):1005-1013.

7. Steele J, Fisher J, McGuff D, Bruce-Low S, Smith D. Resistance Training to Momentary Muscular Failure Improves Cardiovascular Fitness in Humans: A Review of Acute Physiological Responses and Chronic Physiological Adaptations. Journal Of Exercise Physiology Online. June 2012;15(3):53-80.

8. Walker S, Ahtiainen J, Häkkinen K. Acute neuromuscular and hormonal responses during contrast loading: Effect of 11 weeks of contrast training. Scandinavian Journal Of Medicine & Science In Sports. April 2010;20(2):226-234.

Resistance training using your own body weight.

When you walk into most gyms, you will immediately see many different machines and various weight equipment laid out. Each one of these has a specific purpose. As a gym rat, you have the ability to choose between lifting light or heavy weights, based on what you are trying to accomplish in your workout. But sometimes making it to the gym as often as you would like can be difficult or cost more than you can budget. Or it may be that gyms are simply not your thing. If one of these is your dilemma, using your own bodyweight at home or outdoors at the local park can be a great option to be able to incorporate resistance training into your workouts.

Resistance training can help:

• improve muscle strength,
• control weight,
• increase bone density and strength,
• help prevent injury and
• tone your body.

It can also be a factor in minimizing chronic diseases such as diabetes, heart disease, arthritis, back pain, depression and obesity. Bodyweight exercises enable people to workout using natural body movements.

When done correctly and with proper technique, you will be employing functional muscle training that targets multiple muscles at once. Some exercises you might want to consider are:

• Squats (single and double leg)
• Lunges
• Planks 
• Pushups
• Sit-ups
• Calf raises (single and double leg)
• Lower back extension or superman

Each of these body weight exercises can be modified to fit your needs. For example there are multiple ways of doing the plank exercises. You can incorporate the 8 minutes abs routine or use a resistance band.

While an important advantage of bodyweight resistance training is in targeting multiple muscles, having the proper technique is crucial in order to gain the maximum benefit and to avoid injury. Body weight training can be done anywhere - whether at home, on vacation or even surrounded by nature. So next time you find yourself feeling anxious about the gym session you have missed or you simply want to incorporate resistance training into your exercise routine, consider bodyweight exercises.

References from the SIRC Collection:

1. Brubaker E. The Impact of a Six-Week Upper Body Resistance-Training Program Using Arm Bands Versus Body Weight on Upper Body Strength. Virginia Journal. Fall2009 2009;30(2):6-8.

2. Decker J. 6 WEEK SLIMDOWN. Men's Fitness. July 2013;29(7):126-134.

3. Harrison J. Bodyweight Training: A Return To Basics. Strength & Conditioning Journal (Lippincott Williams & Wilkins). April 2010;32(2):52-55.

4. Janiszewski P. The perfect pushup -- just another gimmick?. Active Living. January 2010;19(1):13-14.

5. Stoppani J, MERRIT G. NUMBER CRUNCHING. Flex. June 2011;29(6):96.

6. Yaprak Y. THE EFFECTS OF BACK EXTENSION TRAINING ON BACK MUSCLE STRENGTH AND SPINAL RANGE OF MOTION IN YOUNG FEMALES. Biology Of Sport. September 2013;30(3):201-206.

The underwater treadmill, an alternative to supplementing your training

It is no secret that athletes are always looking for an edge. As an athlete hungry to improve your performance, sometimes you can only train so hard before it becomes necessary to find ways of supplementing your training. Some athletes enhance their workload through cross training, resistance training or even through taking up another sport. One tool that has emerged in the last decade which has high performance and recreational athletes, especially endurance athletes, very excited is the underwater treadmill.

Underwater treadmills have been used to rehabilitate injuries, as in the case of NFL player RGIII of the Washington Redskins. Running on an underwater treadmill can enable runners to add extra mileage without the shock to joints, ligaments, muscles and tendons. This extra compliment to training is a great way to build cardiovascular strength.

A study done by the University of Texas A&M examined the efficacy of water treadmill training for overweight and obese adults and concluded that using an underwater treadmill was as beneficial as running on a land treadmill. The study showed that running on an underwater treadmill improved aerobic fitness and body composition for inactive and overweight individuals. Interestingly, underwater treadmills were seen to increase lean muscle mass in the legs at a greater rate compared to running on a land treadmill. Another study concluded that underwater treadmill running was a viable alternative to maintaining cardiovascular fitness without the demands of running on land.

Benefits of an under water treadmill

• Maintains or enhances performance 
• Reduces the risk of injuries since there is less stress on the body 
• Used as a rehabilitation tool for injury 
• Adds extra mileage without the shock to joints, ligaments, muscles and tendons. 

Whether you are rehabbing an injury, cross training or working to maintain your cardiovascular fitness, an underwater treadmill can be a great form of training without incurring the wear and tear associated with pounding the pavement. From the high performance athlete who needs to rehabilitate or add extra mileage without the added risk of running on land, to the recreational athlete working to maintain fitness or lose weight, the underwater treadmill can be a valuable tool.

This technology is still relatively new. Finding an underwater treadmill in your area may require some diligence and research on your part. The benefits of running underwater however may make the search more than worth it.

References from the SIRC Collection:

1. Brubaker P, Ozemek C, Gonzalez A, Wiley S, Collins G. Cardiorespiratory Responses During Underwater and Land Treadmill Exercise in College Athletes. Journal Of Sport Rehabilitation. August 2011;20(3):345-354. 
2. Denning W, Bressel E, Dolny D, Bressel M, Seeley M. A Review of Biophysical Differences Between Aquatic and Land-Based Exercise. International Journal Of Aquatic Research & Education. February 2012;6(1):46-67. 
3. Hall J, Macdonald I, Maddison P, O'Hare J. Cardiorespiratory responses to underwater treadmill walking in healthy females. European Journal Of Applied Physiology & Occupational Physiology. February 1998;77(3):278-284. 
4. HUTCHINSON A. Go Low Impact. Runner's World. October 2013;49(10):38. 
5. Schaal C, Collins L, Ashley C. Cardiorespiratory Responses to Underwater Treadmill Running Versus Land-Based Treadmill Running. International Journal Of Aquatic Research & Education. February 2012;6(1):35-45. 
6. Stevens S, Morgan D. Guest Editorial. Underwater treadmill training in adults with incomplete spinal cord injuries. Journal Of Rehabilitation Research & Development. October 2010;47(7):vii-xi.