Got up (late) and went straight to the pool for a dip. Just trying to get some good base in today, did 6 x 500 all at about 6:00 minutes with a HR between 120 - 130. Took about 20 to 30 secs rest between 500’s. Then did a 400 IM kick and a 400 IM drill. 200 warm down.

On the trainer in the garage with the door open while watching the rain come down. Watched some Olympic Trial ski competition then the Chargers and the Broncos first couple of quarters. HR never got over 120 and avg. about 113.

32 minutes running 19 laps, 30 minutes swimming 2000 yards, 30 trainer

Ran on the track with Hortie in the rain. It was pouring at first, but the temperature felt great after a couple laps. I was at 4.5 miles at 30 minutes.

Then I swam and my arms felt sluggish and strained. It was hard to get going.

Came home and spun on the trainer for 30 minutes. HR around 120

Wed. - 1 hour swimming 3300 yards then 54 minutes on the trainer / Thurs – 50 minutes swimming 2500 yards, 50 minutes biking to work, 53 minutes running 7 miles

Swimming was hard due to the soreness in my muscles from lifting weights. It is hard to relax the strokes as they feel forced. HR was around 150 after first 400 but then stayed around 120 for the rest of the set.

HR while on the trainer averaged about 115 and cadence was about 110.

I was off to an early start on Thursday, getting up at 6:15 and going swimming.

50 minutes of biking to and from work in very warm temperatures. It was way too hot for booties, but oh so nice; to be outside and riding to work again.

53 minutes of treadmill running. The first 30 minutes started off nice and easy with 7:30 pace. I did a couple of fast paced economy running (sub 6:00) for about a minute. I finished off the last 14 minutes at 6:50 pace. Then I did another 20 minute session and kept it at a pretty smooth 7:00 min pace. The last 6 minutes were closer to 6:40 pace. I managed 4.25 in the first 30 minutes and then 2.5 in the 20 minute session.

Running 1 mile to the Y / Yoga for 1.5 hours and weights for 30 minutes

Ran in the rain to the Y, working on some economy drills. Three times I would accelerate for 15 seconds working on form. Yoga is getting better and better as I feel both stronger and more flexible.

Weights were hardest to date:

Different hormones, different fuel mix

According to Mark Tarnopolsky, MD, PhD, at McMaster University Medical Centre in Canada, men and women differ in the type of fuel they burn as energy for muscle contraction during endurance exercise. For everyone, the major energy sources for endurance exercise are carbohydrate and lipid (or fat). However, in an analysis of 16 different studies, Tarnopolsky determined that women derived 41% of their energy from lipid and 56% from carbohydrate, whereas men burned 29% of their energy from lipid and 65% from carbohydrate.

The reason for the difference? The female hormone estrogen. Estrogen increases the activity of enzymes involved in metabolizing lipids. Tarnopolsky believes that higher levels of estrogen in women translate to proportionally more fat burned during exercise compared to men and less reliance on glycogen (carbohydrate) stored in the muscle and liver.

Effective carbo-loading for both sexes

Given this finding Tarnopolsky wondered if men and women differed in their ability to carbo-load as well. Conventional wisdom holds that loading up on carbohydrates 3 to 4 days before an endurance event will improve performance by boosting muscle glycogen stores. However, most carbo-loading studies have been conducted using males. Tarnopolsky decided to test for differences between the sexes.

Not too surprisingly, when men tapered their exercise intensity for four days while simultaneously increasing their carbohydrate intake from 57 to 75% of total calories, they showed a spike in muscle glycogen stores and a hefty increase in the amount of time it took them to exercise to exhaustion. In short, it worked. The shocker came when women exposed to the carbo-loading regimen showed no increase in muscle glycogen storage or exercise performance.

It turns out that to boost glycogen stores, both men and women need to eat in the range of 8-12 grams of carbs for each kilogram (2.2 pounds) of body weight. For male athletes, this amount of carbohydrate isn’t a problem because their caloric intake is so high. But for female athletes, caloric intakes may be too low to achieve the minimum carb intake needed. The following example illustrates the problem:

Putting it into practice

Paul is a 170-pound athlete who consumes about 3500 calories daily, with 55% of those calories (or about 481 g) coming from carbs. This equates to about 6 grams of carbs for every kilogram of body weight, which is appropriate for light-to-moderate intensity training. To carbo-load he increases the proportion of calories coming from carbohydrates to 75% (about 656 g). This equates to about 8.5 grams of carbohydrate for every kilogram of body weight, which is within the 8-12 gram range needed to maximize glycogen resynthesis.

Amy is a 120-pound athlete and more calorie-conscious. She typically consumes 2000 calories daily, with 55% of those calories (or about 275 g) coming from carbohydrate. This equates to about 5 grams of carbs for every kilogram of her body weight. In attempting to carbo-load, she increases the proportion of calories coming from carbs to 75% (about 375 g). Unfortunately, this equates to less than 7 grams of carbohydrate for every kilogram of body weight, which is below the 8-12 gram range needed to maximize glycogen resynthesis.

At 120 pounds, Amy needs a minimum of 436 grams of carbs, or 1745 calories from carbohydrates. Those numbers may look good on paper, but in practice if she’s only consuming 2000 calories daily, getting 1745 calories from carbohydrate (a whopping 87% of total calories) isn’t realistic.

The solution for effective carbo-loading, according to Tarnopolsky, is that women may actually need to consume 30-35% more calories on carbo-loading days. So, instead of 2000 calories, during carbo-loading 2600 calories a day may be needed. Those 600 bonus calories equate to an extra bagel, a cup of oatmeal with raisins sprinkled on top and a PowerBar Performance bar each day. For those concerned about too many calories, no worries: the green light for extra feasting is only for the 3 to 4 days of carbo-loading.
Fueling during and after exercise

Because women use proportionally more lipid during exercise than men, it is reasonable to think that they might use ingested carbohydrate (from energy bars or sports drinks) differently from men. But that’s apparently not the case. Women respond favorably to ingested glucose in a manner similar to, if not even more so, than men.

When it comes to recovery, several studies have shown that the rate of glycogen resynthesis is greater if carbs, or carbs and protein together, are consumed in the early post-exercise period as compared to hours later. Here again, gender differences in carbohydrate metabolism don’t appear to be a factor. Men and women respond similarly to post-exercise glycogen resynthesis regimens.

Take-home Advice

When it comes to carbo-loading, what works for men won’t necessarily work for women.
Carbo-Loading Tips:

· Gradually taper your training 3 to 4 days before your endurance event.

· Simultaneously increase your carbohydrate intake. For optimal glycogen reloading, men and women require 8-12 grams of carbohydrates for each kilogram of body weight.

· Male athletes can usually achieve the higher carb range by simply substituting carbohydrate-rich foods for other foods that tend to be higher in fat.

· For female athletes, effective carbo-loading may require adding foods to the diet. As a rule of thumb, women may need to increase total calorie intake by 30-35% in the 3 to 4 days before the event.

It is generally well known that replacing fluid lost as sweat is critical for maintaining performance and preventing dehydration. However, drinking too much water or low-sodium beverages during longer exercise sessions and/or in high temperatures can be just as risky, not only to performance, but to your health. It can dilute blood sodium levels and lead to hyponatremia — a dangerous condition, especially in extreme cases.

Your goal should be to stay between your pre-exercise weight and 2% less at all times. For example, if your starting weight was 150, you should stay between 147 and 150. This is your hydration zone. If you gain weight over the course of an exercise session or lose more than 2% of your body weight, your performance and safety can be compromised.

Hyponatremia – the dangers of drinking too much

Hyponatremia is the medical term for low blood sodium. Exertional hyponatremia, is low blood sodium that is believed to occur from consumption of more water before, during and/or after prolonged physical activity, than is lost during the activity. Sodium loss, primarily through sweating, may also be a contributing factor. While milder symptoms include headaches, nausea and cramps, this condition can have tragic consequences. In 2002, two deaths in marathons were attributed to hyponatremia.

Who’s at risk?

Anyone performing prolonged or repeated exercise, for example, triathletes, hikers/backpackers, marathoners, ultra-endurance athletes, adventure athletes and military recruits. Athletes with low sweat rates may be at risk because they may drink more than they lose through sweat. Athletes who are ’salty’ sweaters may also be at greater risk. A recent study showed that those who finished a marathon with hyponatremia were more likely to be female, have a slower finishing time and have taken an NSAID like naproxen, ibuprofen or aspirin, before or during exercise.

Symptoms of hyponatremia

Symptoms of hyponatremia can be confused with symptoms of dehydration or other heat illnesses, so diagnosis should only be made by a medical professional. Symptoms include: swelling and tightness of the hands and feet, fatigue, weakness, lightheadedness and dizziness, cramps and muscle spasms, nausea, vomiting, headache, confusion and seizures.

Prevention

Hydration strategies should take into account an individual’s sweat rate as well as climate, intensity and fitness level. By performing a one-hour test workout you can learn how to more closely balance your fluid intake and fluid losses. To access the PowerBar hydration calculator, click here. Ideally, sweat rate should be determined in conditions that closely mimic actual conditions during the workout or competition.

It’s also important to avoid NSAIDs such as naproxen, ibuprofen or aspirin before or during prolonged physical activity. And if you are on prescription medications, ask your doctor if they have an impact on sodium levels.

If during or after activity you begin to have any of the symptoms of hyponatremia listed above, stop and seek medical attention.
What to drink during endurance exercise

Water provides necessary fluid without carbs. Most juices and soft drinks are too concentrated in carbohydrate and can slow hydration. Sports drinks with a 6-8% carbohydrate concentration (14-20 grams of carbs per 8 oz) serving provide needed muscle fuel during exercise without slowing hydration. Drinks that have a lighter taste will help prevent you from wanting to dilute, therefore keeping the carbohydrate concentration in the optimal range. You also want to look for drinks with 500-700 mg of sodium per liter (approx 120-160mg per 8 oz serving). Sports medicine authorities, such as the American College of Sports Medicine (ACSM), recommend sodium and no other electrolyte during endurance exercise. Note: PowerBar Endurance, one of the newest entries into the sports drink category, has 17g of carbs and 150 mg sodium per 8 oz serving as well as lighter taste to help keep you from wanting to dilute. Read on for information on electrolytes.

Electrolytes–a primer

Electrolytes are minerals that carry an electric charge in your blood and other body fluids. They are involved in many body functions and have important effects on the amount of water in the body, muscle action and the acid-base balance of the blood. The main dietary electrolytes are sodium, chloride, potassium, calcium and magnesium.

Not surprisingly, most Americans need to consume less sodium in their diets and as pointed out in the recently published 2005 Dietary Guidelines, they need to consume more potassium, calcium and magnesium. The story changes as far as sodium is concerned for most athletes. For just about any athlete performing multi-hour workouts, especially in the heat, sodium losses of several grams are not uncommon, with smaller losses of the other electrolytes. Electrolyte concentrations in sweat vary, though. ‘Salty sweaters’ can typically be identified by the white crust on their faces and clothes after a tough workout or race.
What level of electrolyte(s) should be consumed during exercise?

According to current recommendations, sodium is the only electrolyte that should be replaced during exercise. The ACSM, as noted previously, recommend 500-700 mg of sodium per liter of fluid consumed during exercise. This level of sodium may help prevent dangerous drops in blood sodium, while also helping to prevent dehydration-related performance decline. As for the other electrolytes, these are safely replaced through a normal, well-balanced diet.

Hydration Tips:

• Pre-workout, check your hydration status by looking at your urine color. Light colored, like lemonade, is the goal. If it’s dark, like apple juice, drink some more.

• In terms of general guidelines, the American College of Sports Medicine suggests drinking between 6 and 12 oz of fluid every 15-20 minutes during activity.

• However, because of the wide variation in sweating rates (and therefore the general hydration guidelines), occasionally weigh yourself pre and post-workout. If you lost weight, drink more next time (each pound is equivalent to about 16 oz). If you gained weight, drink less. Or check out the hydration calculator, to determine more precisely your own fluid needs.