Altitude training

If altitude training doesn’t work, then why are the Kenyan runners so quick?

Scientific research has been extremely unkind to a very popular form of training – altitude training. As scientists have consistently pointed out, training at altitude usually leads to decreased power outputs (slower running speeds, more lethargic cycling velocities, etc.) during workouts, leading to smaller gains in fitness, compared to training at sea level – where higher training intensities are easier to attain.

However, the consistent scientific pooh-poohing of altitude training presents people interested in running with a bit of a paradox, since the best runners in the world, the Kenyans, constantly train at altitude and loudly proclaim that altitude training is one of the key factors underlying their success. Are the Kenyans wrong, or is their a causal link between their altitude workouts and their world-beating performances?

To try to understand the effects of altitude training more completely, scientists at McMaster University in Canada recently conducted some very ingenious research. At McMaster, 10 males worked out on exercise bicycles three times per week for eight weeks, training just one leg at a time during each workout. One leg would push on a bicycle pedal without the assistance of the other leg while the subjects breathed normal (low-altitude air), and the other leg always worked out as the athletes took in low-oxygen (high-altitude) air. Importantly, workout intensity was kept constant in the two conditions, so that the athletes had to work their low-oxygen leg just as hard as the high-02 limb.

After eight weeks of training, each leg was tested and found to be remarkably similar. Each lower limb had the same V02max (yes, V02max can be measured for a leg – or even a finger) and exactly the same endurance capacity at high exercise intensities. Both legs also made useful improvements in their concentrations of aerobic enzymes – key chemicals which help leg muscles create energy in the presence of oxygen.

However, there was one key difference. The low-oxygen (altitude-trained) leg possessed higher concentrations of an aerobic enzyme called citrate synthase – a very critical enzyme which helps leg muscles use oxygen at high rates. The McMaster scientists concluded that if athletes can train at the same absolute intensity at altitude as they do at sea level, their aerobic-enzyme profiles may improve to a greater extent at altitude.

However, that small phrase – ‘can train at the same absolute intensity at altitude as they do at sea level’ – is easy to write but very hard to carry out in actual practice. The reality is that running at six-minute per mile pace or cycling at 20-mile per hour tempo FEELS significantly harder and requires a higher heart rate at altitude, compared to similar efforts at sea level. That’s why most athletes slow their running or cycling pace at altitude – in order to get the same feeling of effort they attain at sea level.

That means that if your workouts feel about the same at altitude as they do at sea level, you’re probably running or cycling more slowly, and it will be difficult for your altitude training to pay dividends. However, if you ensure that your actual velocity of movement doesn’t drop off, altitude training may be better than sea-level work (it might boost citrate synthase more than lower-ground exertions). The problem is that the thin, high-altitude air will make the altitude workouts pure hell.

So what about the Kenyans? They are masters at working hard all of the time – but working even harder at altitude and enduring fiendish workouts. A Kenyan who runs one-mile intervals in 4:30 at a moderate-altitude (5500 feet) training site in Nairobi may run mile intervals at the same pace in a place like Nyahururu (elevation 8200 feet), for example, even though the Nyahururu efforts feel as though they will tear the lungs asunder. It’s important to remember, too, that most of the Kenyans have grown up at altitude, so they can adapt to increases in elevation more easily than the sea-level native.

The final word? If you go from sea level to altitude for training, it’s important to maintain your average speed of movement. If necessary, use short intervals to achieve high training speeds during your first few weeks at altitude. If you’re rich enough, you should try to alternate three-week periods at high altitude with similar durations at low altitude. The high-altitude sojourns will boost your blood with red cells, and the sea-level exertions will make it more likely that you will train at really high levels.

Another excellent strategy is to live in a place where changes in elevation can be made quickly. For example, living at 7500 feet or so and driving for 45 minutes or less to a training location at 4000-5000 feet is not too inconvenient and could give you nice blood – and really intense training. Otherwise, if severe pain is your special friend, you can just spend all of your time at moderate to high altitude and work out unbelievably fiercely – as the Kenyans do.

(Is Hypoxic (Altitude) Training More Effective than Sea-Level Training for CompeVtion at Sea Level? Canadian Journal of Applied Physiology, vol. 18(4), p 422P, 1993).