Tidbits

Performance Effects of Environment The optimum temperature for long distance running performance seems to be around 50-55°F (10-13°C). Performance degrades as much as 2% for every 5°F (2.75°C) above or below this range. High humidity in high temperatures can increase the effective ambient temperature by up to 10°F (5.5°C) by inhibiting evaporation. Direct sunlight can increase temperature by up to 8-9°F (5°C). Special caution should be advised when the temperature exceeds 80°F (27°C) or relative humidity surpasses 50-60%. Also see Wind Chill Chart and Heat Humidity Index Chart. Vascular Dimensions The aorta, one of the largest arteries in the body, is the diameter of a garden hose. In contrast, ten capillaries are equal to the thickness of a single human hair. The human body contains about 6 quarts of blood which circulate through the body three times every minute. Each day, the blood travels about a total of 12,000 miles (19,300 km) per day (4 times across the US from coast to coast). In a lifetime the human heart will pump about 1 million barrels of blood - enough to fill over 3 super-tankers! Diagram of the Organs of the Circulation L: pulmonary circulation M: circulation through the organs suspended by the mesentery P: circulation through the liver The circulation through other organs, such as brain, muscles, skin, and kidneys, is indicated. Lymphatics are represented by dotted lines. Heart Volumes (ml)   Male Female Athlete 860 725 Non-Athletic 670 580 Heart Pump / Machine Pump Group Exercise Music - Beats per Minute (BPM) Class BPM Floor work / Muscular conditioning 115-135 Step 120-128 Interval 120-128 Slide 120-130 Cycling 124-130 Hi/Lo 135-160 Running and Pain After 50 Runners 50 years of age or older suffer 25 percent less musculoskeletal pain B Fries, JF Fries, DP Lubeck (2005). Aerobic exercise and its impact on musculoskeletal pain in older adults. Arthritis Research and Therapy, 6(7): 1263-70. Fat Metabolism & Aerobic Intensity The total rate of fat oxidation during exercise is greatest at higher intensities that are below lactate threshold. For example, during exercise at 20% of VO2 max, approximately 60% of the energy would come from fat. By comparison, exercise at 50% of VO2 max, only about 40% of the energy would come from fat. Nonetheless, the absolute amount of fat metabolism is 33% higher during exercise at 50% VO2 max since the total energy expenditure is 250% greater than exercising at only 20% of VO2 max. The greatest absolute fat metabolism during exercise occurs at 50% of VO2 max in untrained subjects (body weight: 89 kg; VO2 max: 4.0 L/min; lactate threshold: 60% of VO2 max). Lactate Threshold Lactate threshold (controversy AKA anaerobic threshold) is the point at which blood lactic acid rises systematically during graded exercise. Lactate threshold occurs in untrained subjects around 50-60% of VO2 Max and in trained subjects around 65-80% of VO2 Max. Lactate threshold can be used as a marker of training intensity. It can also be used in combination with other physiological measurements, such as VO2 max, as a predictor of long-distance running performance (Farrel P, et al. 1979; Marti B, Abelin T, Howald H, 1887). Oxygen Consumption A steady state of oxygen uptake can be maintained during prolonged low-intensity exercise. Exercise at a relatively high work rate or in a hot and humid environment results in an upward drift in oxygen consumption over time so a steady state is not obtained under these circumstances. During incremental (graded) exercise, oxygen uptake increases linearly until VO2 max is reached. Outdoor vs Treadmill Running The Aerobic demand for outdoor running at 5 m/s is 5% to 7% higher than that for treadmill running. Jones AM, Doust JH. A (1996). 1% treadmill grade most accurately reflects the energetic cost of outdoor running. J Sports Sci. 14; 321-327. A Horse's Dynamic Red Blood Cells In the horse, circulating hemoglobin concentration doubles from rest to maximum exercise. This great augmentation of oxygen delivery to the working muscles presumably accounts in part for that species' remarkably high VO2 max (approximately 160 ml/kg/min). This is 3 to 4 times higher than in a fit healthy human. In humans, there is virtually no contribution to the increase in VO2 by hemoglobin concentration changes from rest to exercise. Wagner, PD, (1991) Central and peripheral aspects of oxygen transport and adaptations with exercise, Sports Medicine, 11 (3): 133-142 Progression and Recovery After a hard workout, take a day off or have an easy workout. Increase your weekly distance no more than 10 percent. After a few weeks of distance increases, drop distance by 50 percent for one week. Occasionally, reduce your weekly distance by 10-15 percent while increasing your pace by 6 to 12 seconds per kilometer (10 to 20 seconds per mile). Walking the USA In 1909 Edward Payson Weston walked 3,795 miles from New York to San Francisco in 104 days and 7 hours. Along the way he endured many obstacles such as heavy blizzards. At the time, he was celebrating his 70th birthday. The following year Weston walked back to New York from Los Angeles. He completed the 3,600 mile trek in 76 days and 23 hours. Average Marathon Times in US (2005) Men: 4 hours 32 minutes 8 seconds Women: 5 hours 6 minutes 8 seconds Marathon World Records Men: 2:3:59, Haile Gebrselassie (Ethiopia), Berlin Marathon, Sept 28, 2008 average pace: <2:57 per kilometer (4:44 per mile) average speed >20.4 km/h (12.6 min/hr) Women: 2:15:25, Paula Radcliffe (Great Britain), London Marathon, April 13, 2003 Concept II Rower (2500 Meter Records): Men: 7:10.7 Women: 8:12.5 Precor EFX Distance Conversions Strides Miles Km 560 0.25 0.4 1120 0.5 0.8 1680 0.75 1.21 2241 1 1.61 3361 1.5 2.41 4482 2 3.22 Handrail You burn 7% fewer calories for every 10 pounds (4.5 kg) of weight you lean on the handrail of a stair climbing machine. (typical 143 lb person x 7% = 10 lbs) Decline in Aerobic Endurance Entering the second half of life, the average adult loses 1.5 percent of aerobic capacity per year (Cooper 2007). Purchasing Shoes Your feet are not identical so fit the larger one when buying shoes. The best time of day to shop for a shoe is at the end of the day, when your foot is the largest. A long jog in warm weather can expand a runner's feet as much as half a size. Test shoes before you buy them. Good shoes should feel comfortable when you first try them on, not after they have been broken in. Buy new running shoes every 240 to 450 miles (400 to 725 km). Buy new walking shoes every 400 hours of use (e.g.: after 40 week of 10 hours of walking per week). Many models of running shoes are now especially designed for those who pronate as well as those with a standard gait. Left: Standard Middle: Pronate Right: Supinate