I don’t like to write about things that I haven’t actually practiced or experienced, but aging is something that we all do with varying degrees of effectiveness. If you read about the ravages of getting old, it is very scary. If you read about the positive effects of exercise, nutrition, and stress management on the aging process, you gain some sense of control; it all becomes more interesting and challenging. Consider that much of “normal aging” is actually mediated by disuse (hypokinetics), too much stress, and poor nutrition. The good news is that it is never too late to make positive life-style decisions or to start training for next year’s racing season. Here are a few key factors relating the physiology of aging and physical training.

Concept VII: The Aging Paddler

Physiology: The study of aging typically views a cross section of population that is not devoted to exercise and fitness. So, the norms that we read about tend to be skewed towards aging of the sedentary rather than aging of the fit. Older athletes are not only concerned with maintaining health and fitness, but are searching for ways to improve athletic prowess. Consider the aging effects on 1) the cardiorespiratory system and 2) the skeletal muscle system:

1. Maximal heart rate tends to decline with age by approximately one beat per minute each year. Exercise may alter this process minimally, but heart rate decline is inevitable. Stroke volume, which reflects the muscle quality in the left ventricle of the heart also may decline. The resulting diminished cardiac output reduces circulation to the exercising muscles, therefore, limiting the VO2max potential. However, research has shown that a group of aging nationally ranked marathoners were able to match their 25 year old VO2max at age 40. Aging is slowed by training!
2. The inactive older person tends to lose muscle and gain fat as a result of the body’s physiologic adaptation to reduced activity. This adjustment in body composition stimulates a decline in resting metabolic rate (RMR) which decreases caloric need and increases calorie storage (fat). Muscle mass loss is the reduction in both the number and size of the muscle fibers. Also, motor nerve cells which activate the muscles tend to deteriorate. Collateral nerve development may help to reinnervate some of these abandoned motor units. However, muscle mass (and motor units) may be preserved by training!

Old muscles respond to exercise just as well as young muscles. Exercise helps to preserve and improve muscle and nerve quality and function, coordination, flexibility, posture, etc. Although some potential strength loss occurs because of the dwindling fast-twitch muscle fibers, resistance training and endurance training provide the adaptive stimulus to fight these aging phenomena.

Training: Of the three primary training variables, VO2max, economy, and lactate threshold (LT) (see previous Training Concepts), the aging athlete may derive the greatest performance gains through LT training. Mitochondria and oxidative enzymes (which support oxygen utilization in the muscle cells) are key functional elements of the aerobic process and they tend to survive aging. These elements are very responsive to training and are responsible for optimizing aerobic capacity and LT. Maximizing mitochondria and oxidative enzymes allows more energy production during exercise and results in faster and longer paddles.

Research gives us some ideas about training in order to increase the density of mitochondria and oxidative enzymes in the muscle cell:

• Oxidative enzymes are maximized by training 1 hour per day, 5 days per week, for 6 months.
• Mitochondrial density is most efficiently increased in slow-twitch muscle fibers by paddling for 60 minutes at 70-75% VO2max (80-84% HRmax).
• The best way to stimulate the oxidative capacity (increase mitochondria) of fast-twitch fibers is to paddle for 10 minutes at close to 100% VO2max. Fast-twitch muscles prefer to operate anaerobically but can be trained to assume some intermediate oxidative characteristics.

It is apparent that variation in intensity and duration is necessary to take care of training every facet of our physiology. It takes some planning and creativity to tailor a training program to include the stimulus for all the desirable adaptive traits.

Proper training greatly improves endurance in old age, probably by the same mechanism as in youth (the muscle’s increased ability to use oxygen reduces glycogen depletion). Adaptability of muscle to exercise remains high even in the very old and the response to training does not appreciably change with age. Much of the deterioration of muscle tissue associated with aging appears to accompany disuse.

How to raise your lactate threshold? A high LT tends to compensate for a declining VO2max. Ideas about LT training are continually evolving. Without dwelling on the physiology of lactate threshold, try this simple 45 minute program each week (optimally 30% +/- of your training workload):

1. warm up, hydrate
2. paddle hard for 12 to 15 minutes
3. recover with easy paddling for 4 minutes
4. paddle 30 minutes of quality paced 250m intervals with equivalent length recovery times (or 75 second intervals with 75 second recoveries)
5. warm down, rehydrate

As you get older, be sensitive to your changing needs. You may require more recovery time between hard workouts or after racing. Overtraining caused by insufficient recovery will hinder your performance and substract from the fun quotient. Also, be patient and let your training work for you. Don’t try to force yourself into higher performance. Give your body a chance to adapt to the workload. Set goals and allow enough time to achieve them; start preparing now for next year’s favorite races. Consciously monitor your state of well-being both during races and throughout your training.

Conclusions: Think of the change in certain human qualities as we age in a positive way and accept the challenge. Age related strength loss is compensated for by smart training and keen racing skills. Add to this optimal stroke mechanics, a slick new carbon fiber boat, and a light weight carbon paddle. You will enhance your lactate threshold paddling velocity (LTPV), and gain a performance advantage. Aging doesn’t have to be all that bad!

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