Showing posts with label cardiovascular training. Show all posts
Showing posts with label cardiovascular training. Show all posts

5/15/2015

Add Horsepower to Your Cardio: Increase Your Cardiac Ouput

QUESTION: True or false:  to improve your cardiovascular conditioning,  get your heart rate as high as possible in aerobic exercise?


ANSWER: False.  You improve your cardio condition by increasing cardiac output at lower heart rates.   Here's the mathematical equation used by doctors and exercise physiologists:

Q = HR x SV
Your cardiac output, Q,  is the product of your heart rate times your stroke volume - that's the amount of blood exiting the heart from the left ventricle every time it beats.   A strong heart pumps more blood with every beat.  At rest, Q is typically about 5-6 liters per minute.  During exercise it can be 3-6 times as much.  

Extra Horsepower
To improve your cardiovascular conditioning, we focus on improving your Stroke Volume, conditioning the muscle fibers in the heart to pump more blood each time it beats.  Think of it as adding horsepower to a pump.

We do this with a training program designed to increase your heart rate reserve --- the difference between your Resting Heart Rate and your Maximum Heart Rate.  Your Maximum Heart Rate is most widely accepted at 220-age, it is a theoretical number that is the same for everyone.  


We can’t change your Maximum Heart Rate, but we can lower your Resting Heart Rate. Typical Resting Heart Rate for adults is 60-80 beats per minute, if you’re already well conditioned it is probably lower.

The Frank-Starling Law
For over 100 years, doctors have relied upon the Frank-Starling law or mechanism for patients with heart arrhythmias and cardiac failure.  It explains how the heart adapts to changes in heart rate and stroke volume, and applies equally to exercise.

If you train your heart to pump more blood what’s it going to do?  Pump more blood.  You will also see a lower resting heart rate and - as your heart rate reserve increases - an increase in potential cardiac output (Q in the formula discussed above).

If you train your heart to beat faster, what’s it going to do?  Beat faster.  You may not see improvement in cardiac output, in fact it may even decline.  Frank-Starling explains that  if the heart is literally beating so fast that the chambers don’t have time to fully fill with blood, the muscle contraction is not as strong. The muscle can actually weaken slightly over time.  You burn more calories at a higher heart rate, but there's a good chance that you're burning muscle and not just fat.  More about this in an upcoming article on Metabolic Training.

Your Cardio Training Heart Rate
We use the Karvonen Formula to calculate your training zone, also called the Heart Rate reserve formula.  (More elaborate athletic training facilities may use VO2 max as a measurement, but it is difficult to consistently monitor).
  • 60-80% of your Maximum Heart Rate, using the Karvonen formula, is targeted to increase stroke volume, therefore increasing cardiac output and lowering your resting heart rate. Gradually increase intensity of exercise that you are able to do while keeping your heart rate in this range.
  • Above 80% of MHR not indicated for improving cardiac output.  It provides other benefits such as improving lactic acid removal and strengthening fast twitch muscle fibers. So it is part of your program, but not the part that improves cardiac output.
To calculate your Target Heart Rate Zone, take your Resting Heart Rate early in the morning,. preferably when you wake up without alarm or kids or noise and use the following equation:


THR = (220-Age-RHR) * Desired Intensity % + RHR

Do I need a Heart Rate Monitor?
Ideally yes, but you can also use rate of perceived exertion.   The Borg Scale is widely used, easy and scientifically validated,  you rate your perceived level of exertion on a scale of 6-20, where 6 is no exertion and 20 is extremely difficult  A rule of thumb is that you can then multiply by 10 to get an approximate heart rate.   

Proceed with caution

Talk to a doctor and a fitness professional before beginning a new exercise program or substantially increasing the intensity.  I'd be happy to meet with you to discuss your questions, goals and program options.  Contact me  if you have any questions or want to set up some sessions to develop your personalized program, or visit TrainerCary.com for more information.

7/26/2012

Myths About Perspiration, Fluid Replacement Guidelines, Your Personal Hydration Program

We're on track for ta hot summer, and with everybody sweating more, many of you have asked about hydration and fluid replacement strategies.

This posting  reviews common myths about perspiration and provides hydration and fluid replacement guidelines to enhance performance and avoid heat related illnesses.  Information comes from authoritative sources including position stands of The American College of Sports Medicine and peer reviewed publications of the National Strength and Conditioning Association.



MYTHS ABOUT PERSPIRATION

#1 - The More I Sweat the More Calories I Burn.  FALSE.  Perspiration is part of our body's cooling system, it does not necessarily require burning calories or correlate with caloric expenditures.  Example:  stand outside on a very humid 90 degree day, and you will sweat profusely.  Run indoors in a very dry 65 degree environment, and you may hardly break a sweat.

#2 - I Can Sweat The Weight Off.  FALSE.  -Weight loss due to sweating indicates dehydration.  This weight is water that needs to be replaced, it is not the stored body fat that you really want to lose.  In sports like boxing, MMA and wrestling, participants may temporarily sweat off a few pounds to make weight - but will immediately begin rehydration before the exercise event.

YOUR BODY'S HEATING AND COOLING SYSTEM 
Whether from exercise, movement or shivering, muscle activity generates heat, which your blood circulates. Your body cools itself by increasing blood flow close to the skin and through evaporation of sweat. Research has shown sweat rates range from .5 to 2 liters per hour with marked differences between individuals.  The amount of sweat varies based on individual characteristics such as body weight, genetics, heat acclimatization, and conditioning, and environmental conditions such as heat, humidity, clothing and equipment. 

EUHYDRATION, DEHYDRATION, HYPERHYDRATION  
Euhydration means we're at our normal hydration level and weight, and this is the most desirable state.  For most people water is about 60% of body weight when we are euhydrated. Dehydration is easily measured by calculating lost body weight before and after exercise.  Ten to 14 days of training in heat will help you acclimatize and reduce risk of dehydration.

  • Lose 2% of body weight, aerobic exercise performance and cognitive abilities are degraded. 
  • Lose 3-5% of body weight, there is risk of heat related illness.  The rate of sweat production declines and can lead to hyperthermia - overheating of the body and brain.  Life-threatening exertional heatstroke occurs when body temperature exceeds 104 and internal organs begin to shut down.
Whether you're working out, running, walking, or even sitting outside in hot humid weather, every pound you lose is a sign that you've lost about a pint of water. Hyperhydration, drinking an excessive amount of water before an athletic event or exercise (more than euhydration), has not been found to improve athletic performance and is not recommended.

GENERAL FLUID AND ELECTROLYTE GUIDELINES
NSCA provides the following general guidelines for fluid and electrolyte replacement:
Before exercise event:  Drink 16 ounces of water two hours before;  drink 8 ounces sports drink 10-20 minutes before.
During exercise event:  Drink a sports drink that contains 30-60 grams of electrolytes and 120-240 grams of carbohydrates per hour to prevent fuel depletion.  Drink 8 ounces of fluids every 15-20 minutes.
After exercise event:  Drink 2-3 cups of fluid for every pound of body weight lost.
Competitive athletes, marathoners and triathletes will benefit from a more personalized hydration program tailored.

YOUR PERSONAL HYDRATION PROGRAM
 Developing your own individualized program is actually easy. ACSM'smost recent position stand on fluid replacement  recommends individualized programs because our sweat rates vary.

Weigh yourself before and after exercise to determine your rate of fluid loss due to sweating, and rehydrate accordingly.  If you lose a pound in a half hour, replace it with 16 ounces of fluid per half hour of exercise.  This may vary depending on weather, intensity and clothing, but over time you should be able to make adjustments.

Begin to prehydrate a few hours before your exercise event, so that your stomach contents are emptied, fluids are absorbed by your body, and urine flow returns to normal.  Rehydrate during the exercise event to replenish the fluids being lost. 

ELECTROLYTES, SODIUM AND HYPONATREMIA
Electrolyte and sodium depletion and replacement is more difficult to individually quantify and program because it requires blood testing.

  • Electrolyte and sodium depletion can cause muscle cramping.  
  • Profuse sweating over time can literally flush sodium out of your body;  if not replaced, a dangerous condition called hyponeutremia resuts.    
Most people don't need to be overly concerned with hyponatremia, but participants in extended exercises events, including marathons, triathalons and sports in hot humid weather should consider electrolyte replacement or salt tablets. The concern here is the potential for athletes to overhydrate with water.

Interestingly, ACSM has found that sodium replacement does not reduce cramping in triathletes, implying that muscle fatigue and energy replacement may be more important factors. 
 Contact me  if you have any questions or want to set up some sessions to develop your personalized program, or visit TrainerCary.com for more information.

5/03/2010

Interval Training: Burn More Calories. Improve Performance. Reduce Exercise Time.

Yes this sounds almost too good to be true.

Interval Training involves alternating between higher and lower intensity in your cardio workout. It could be right for you if you have a good cardio base and want to improve performance or results. If you're just beginning to train, we start by getting your cardio base established first, and prepare your body for the demands of this training. A cardio base is usually established with moderate exercise, 60-70% of your maximum heart rate or a rate of perceived exertion of about 5-6 on a scale of 10*. (A simple estimate of your maximum heart rate is 220-your age, I can give you a better estimate if you give me your age and resting pulse).

Research shows that Interval Training burns more calories than training at a steady rate, partly because it raises your metabolism for 2-3 hours after you stop exercising. The scientific term for this phenomenon is EPOC for Excess Post Exercise Oxygen Consumption. It also seems to cause molecular changes in the muscle that increase fat burning. Interval Training may also improve your performance by increasing your body's ability to remove lactate from the bloodstream, so it can help well-trained people get to the next level. This point is often described as reaching your anaerobic threshold or "going anaerobic". Scientists now believe that "going anaerobic" is a myth, - along with "the myth of the Fat Burning Zone." Remember that you burn more TOTAL calories in the cardio zone than in the fat burning zone, and interval training can help you get there. Numerous studies have shown that for many people, interval training produces better results in less time than steady state aerobic training.

A typical starting interval training program might consist of a warmup followed by 60 seconds of high intensity exercise followed by 90 seconds of recovery at a lower intensity repeated about ten times. As you become more conditioned, decrease the recovery to 60 seconds. In more advanced programs, the high intensity intervals can be 2-3 minutes long, with rest periods equal to or less than the high intensity interval. High intensity exercise generally means that your heart rate is 75-85% of maximum, and the recovery rate is about 60%. To use rate of perceived exertion, you should feel that you're at about 8-9 on a difficulty scale of 1-10 in the high intensity period, and about 5-6 in the lower intensity period.

You can do interval training on any cardio equipment, or with other activities such as running or jumping rope. Beginners may get their heart rate up with walking on a treadmill and varying the incline, while very fit people will need to do something more challenging.

4/30/2010

Special Feature: Interview with NYSC Spin Master Rob Merluza

A snowstorm in February provided a long-awaited opportunity for me join one of Rob's spin classes at NYSC Wall Street --- his classes and my evening schedule are usually totally booked. We followed up with an interview:
Q: What's the Goal of Your Class? My classes are tailored to maximize effectiveness in 45 minutes. The focus is high intensity interval training, one of the best ways to maximize results.

Q: What Sets your Classes Apart? The thing I'm known for is that my classes simulate an outdoor ride, simulate real hill climbs. To round out the experience and make it enjoyable, I use tailor each song to the exercise, providing a nice rhythm and beat to accompany the ride.

Q: How do you keep it going? My classes focus on different areas such endurance, strength with increasing resistance, staying in the aerobic zone. I throw in a kicker - sprints - to get the class into a higher zone, increase heart rate and calorie expenditure, really tax the system. Throughout, I'm always cognizant of providing adequate recovery between sprints and intervals.

Q: What else can your students expect to learn? I touch on proper form and technique, improved pedal stroke, body alignment and positioning - so that the body works in synergy with the bike.

Q: Can you tell us some of the benefits of your class? Beginners can expect to burn about 400 calories in a class. They may not do all sprints or have endurance to maintain a high energy level throughout, but will feel a sense of accomplishment, get a good workout, and begin building their aerobic base. Moderate to Advanced students can burn 500-800 calories. I focus on challenging them to increase resistance, go harder on sprints, and maintain a high level of intensity.

Q: What about results? I've had members who've lost 30-100 pounds - including one of your clients who combined my spin classes with your strength training program and had great results. They also gain increased endurance, improved strength and leaner appearance. With advanced riders and triathletes, I focus on creating a "strong engine" for the ride - a combination of form, position, pedal stroke and aerobic base.

Rob's Spin classes are Thursday at 6PM and Friday at 530PM at NYSC Wall Street, advance reservations required call 212.482.4800.

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