Maximun Rate (HRmax)

32% of the population will have a maximal heart rate greater than +/- 11 bpm different from the HRmax. (Max Heart Rate: Age-Related Decline)

Target Heart Rate

Formulas for estimating Max Heart Rate (HRmax) and Target Rate Examples
Examples for a age = 50 yrs., resting rate = 59

Formula	MaxHR	60-75%	>75-85%
Male
(220 - age) (Non-athletic)	170	102-128	128-145
208 - 0.7 * age (Dr. D. Seals U. Colo.)	173	104-130	131-147
214 - 0.8 * age	174	104-131	131-148
(205 - age/2) (Fit)	180	108-135	135-153
MaxHR=214 - 0.8 * age; Target = Resting HR + (Max HR-Resting HR)*%HRMax)	174	128-145	145-157
(220 - age + resting rt.)/2	115	86	97
Resting Rt. + %HRMax (220-age-resting) + 10 (if resting <60)	180	136-152	152-169
Female
(226 - age) (Non-athletic)	176	106-132	132-150
(211 - age/2) (Fit)	186	112-140	140-158
209 - 0.7 * age	174	104-131	131-148

Heart Rate calculator Spread Sheet

Karvonen Formula:
Resting Rt. + %HRmax (220-age-resting) + 10 (if resting <60)
%HRmax=60-75% (Easy), 85-90% (AT), 90-100% (VO2) 

Aerobic threshold:
The lowest exercise intensity at which blood lactate markedly increases above resting level. Almost all energy is produced aerobically and you could exercise at this intensity for hours.
It is when blood lactate reaches a concentration of 2 mmol/litre (at rest it is around 1)

AT: Anaerobic threshold -

Exercise intensity at which anaerobic metabolism increases and blood lactate starts to accumulate. This is the highest exercise intensity that can be sustained for a prolonged period.
The amount of available oxygen is no longer sufficient to meet the body's energy demands and a second pathway called anaerobic ("without oxygen") glycolysis is recruited. The end product of anaerobic glycolysis is lactic acid (lactate). As running pace is increased futher, the lactate concentration in the exercising muscles increases rapidly and this point is referred to as tha anaerobic threshold (AT) or lactate turnpoint. Subjectively, this is where a pace at which breathing becomes more labored and the dreaded burning sensation in the legs begins to appear. Well-trained athletes usually reach their AT at approximately 85-90% of their VO2max heart-rate, but for untrained individuals this threshold is much lower (50-70% of VO2max heart-rate).

How to measure AT:
1.Conconi test - Plot the heart rate over speed/workload for different levels of workout.
2. Handheld blood lactate meters.
It is when blood lactate reaches a concentration of 4 mmol/litre .
3. Gas exchange.
This lactic acid is buffered primarily by bicarbonate. The bicarbonate-derived CO2 causes an increased alveolar CO2 output relative to O2 uptake.

VO2 - This represents the maximum rate of oxygen consumption for a person, in liters per minute. Usually around 95% of your maximum. 55% of VO2Max usually occurs at about 70% of HRMax A good rule of thumb is to run no more than 10% of your weekly mileage at this pace.

Source: Eoin Fahy, Ph.D.
See also VO2max at Indiana.edu

The talk test is another good way of establishing how hard you are working, if you find it difficult to say a few words, you are probably working out anerobically. For a good indication of aerobic exercise, you should be able to say a few words, catch your breath, and then carry on talking.Ê

Note: The generally accepted error in the age-predicted formula is ± 10-12 bpm, which is due to different inherited characteristics and exercise training. I've seen articles which say individuals can vary by up to -20 to +30 beats/min. The most accurate way of determining your individual maximum heart rate is to have it clinically tested (by treadmill or bicycle stress test) by a cardiologist or exercise physiologist.

Heart Rate Zones:
The fat burn zone (60-70% of HRmax) occurs frequently on workout machines in gyms.
The Polar heart rate monitor has the following zones.

WebMD says it's not true that Moderate exercise promotes weight loss more effectively than vigorous exercise. You have to burn more calories than you consume and greater exertion burns more calories.

BuiltLean Creator Marc Perry, says During exercise your body draws energy from primarily two places: fat stores, or glycogen stores. Glycogen is stored carbohydrates in your muscles and liver.
At 50% of your max heart rate, your body burns a ratio of 60% fat to 40% glycogen. At 75% of your max heart rate, the ratio is 35% to 65%, and at even higher intensities, the ratio is even lower.

30 Minutes of Exercise	Fat Calories Burned	Glycogen Calories Burned	Total Calories Burned
Low Intensity Group (50%)	120	80	200
High Intensity Group (75%)	140	260	400

So, why work so much harder to burn only a little more fat. Because of the Afterburn Effect. Higher intensity workouts cause a metabolic disturbance that burns calories after the workout is completed.
During high intensity exercise, you are burning primarily glucose, but after is when you burn the fat.

livestrong.com says "Exercising at 95 percent of your maximum heart rate in short segments can burn more calories overall than maintaining a steady heart rate throughout a workout."

See The Myth of the Fat-burning Zone | ACTIVE

• 1. The Zone, Barrry Sears, 1995
• Eoin Fahy, Ph.D.
• StevensCreek Sftwr.
• Running Free
• Life Fitness
• Body Trends
• NutriBase.com
• Exercise
• Calories burned