I lined up for the Robin Hood half marathon yesterday hopeful, but uncertain. I had a successful six months of training behind me. By using of the sub-maximal tests described in my posts in June and July to monitor for signs of over-training, I had managed to achieve a 10 % greater training volume than I achieved in the corresponding six months last year. My aging legs had coped well. My aerobic capacity had improved slowly but steadily throughout the six months, and furthermore I had managed to do a large number of training runs longer than 15Km, many of them in the range 18-21Km, so it was reasonable to expect that my endurance would be adequate for a half marathon.
In several of these long runs I had increased pace progressively, aiming to reach something near race pace in the final few Km. However, the disappointing observation was that I had struggled to achieve a pace any faster than 5 min/Km in these runs. On the one occasion when I achieved even this modest pace, my breathing and heart rate indicated I was already beyond the anaerobic threshold. Simple physiology indicated that a 100 minute target for the half marathon (4:44 /Km) was unreasonable, but I pinned some hopes on the fact that in last year’s Robin Hood half marathon, I had run far better in the race than prior training suggested was possible. While my aerobic capacity wasn’t quite as good this year, I was confident that my endurance was better. So I planned to start at around 4:50 min/Km and adjust pace according to how well I was coping.
The weather was ideal for distance running: broken light cloud with bursts of sunshine and a cooling breeze. Within the first few hundred metres I was a little surprised to see my heart rate shoot up to an alarming level and wondered whether there might be an impending cardiac problem. However it soon settled to a reasonable level. Perhaps I was a little more nervous about this race than usual. I covered the first two Km at 4:53 min /Km (103 min HM pace). I felt much more comfortable than I had felt at a similar pace in training, but it was clear by 3 Km that I would not be able to maintain that pace for much longer. My breathing was still quite comfortable but my legs were not coping. In an attempt to reduce the impact forces on my legs, I increased cadence to over 200 steps per min, but my stride gradually shortened further and pace gradually ebbed away.
Although it was clear in the later stages that I would be far short of my target, and indeed had no chance of even achieving 105 minutes, I pushed on as fast as my failing legs would carry me in the final few Km. However the increased effort was to little avail. As each runner went by I tried to lift my pace, but despite my attempts, each one forged inexorably ahead. Then with a little over 1 Km to go I spotted a young lady with a pink top and swishing pony tail who had passed me about 16Km earlier. The gap was slowly closing, so I had a target for the final Km. I caught her as we climbed up to the flood defence embankment with a few hundred metres to run. She defended strongly for a few metres but I was able to find a little extra drive. So despite being passed by many in the final stages, I claimed one scalp at the end. My finishing time was 107:49
Afterwards I felt pretty wobbly and a couple of first aiders were quite solicitous for my welfare. I managed to stay upright though I did need to steady myself against a tent pole. I wasn’t in danger of fainting; I was simply exhausted. So what does the future hold? I trained about as well as I could have for this event, but I am not yet ready to abandon hope of pushing back the tide of advancing years. Perhaps on another day I might have achieved a time better by a few minutes, but if I want to run substantially faster in future, I need to carefully evaluate my strategy.
It is important to note that my aerobic fitness did improve steadily during the six month of training. In the final sub-maximal test, done during the taper, I achieved 650 heart beats/Km, whereas 6 month previously, shortly after resuming training after a bout of arthritis, the rate was nearer 750 beats/Km. But the improvement throughout the six months had been painfully slow. In 2010, when the year had started with a bout of arthritis similar to this year, I had made greater improvement in aerobic capacity in less than 3 months, with a much lower volume of training at a higher intensity. However that year, my half marathon campaign was stymied by a several illnesses in the summer. Nonetheless the progress in spring of that year indicates that higher intensity training would be likely to produce a more rapid gain in aerobic capacity.
The phenomenal marathon performances of Ed Whitlock, who does a very large volume of low intensity training, spiced up with fairly regular races, demonstrates that a program based largely on low intensity training can work well. However, despite the relatively satisfying demonstration that I could cope with a moderate volume of training this year, it appears that I am unable to cope with anything like the volume of training that Ed Whitlock does. He doesn’t record distances, but runs for several hours each day at an easy pace. If I increase my training volume to 50 miles in a week, even at an easy pace, I experience rapidly accumulating exhaustion. So, if I am to produce substantial further improvement in aerobic capacity, greater intensity offers the best prospect.
As I have described on several occasions previously, there is good evidence that high intensity interval training can produce increases in aerobic capacity, including increases in aerobic enzymes and muscle capillary density. At this stage, I am very tempted to try HIIT for at least a few weeks, as soon as I have recovered from yesterday’s race, to see how well I cope with it.
But there is little doubt that yesterday the principle limitation was my lack of leg muscle power. I had reached a similar conclusion last year. Loss of muscular strength is one of the most overt problems of the elderly, and therefore at that stage, the logical step was a program of weight training to increase strength. Since squats provide a very good ‘whole body’ workout, with particular benefits for legs and trunk, I embarked on a program of squats augmented by dead lifts. In the final months of the year, I made major gains in strength, increasing my 5 repetition maximum (5RM) for squats from a little over half my body weight to more than 160% of body weight in a period of three months.
I had intended to follow that lifting with a program of plyometrics to increase my capacity to handle the eccentric loads that the leg muscles bear at footfall when running. Unfortunately, the episode of arthritis confounded that plan. Since recovering from arthritis, I have continued a maintenance program of squats, and my 5RM has only deteriorated only a little. However, apart from a small amount of trampolining, I have not dared to introduce plyometrics for fear of stressing my fragile joints.
The crucial test of eccentric strength is hopping. Unfortunately, the distance I can cover in five hops has deteriorated by about 20 percent compared with three years ago. It is interesting to note that subsequent to the program of weight lifting, my performances on the elliptical cross trainer have been better than at any time in the past three years. Since the elliptical requires a leg action similar to running, apart from a minimal requirement for eccentric contraction, it is almost certain that the increased strength has helped me perform better on the elliptical, but has had little impact on my running because there has been little improvement in eccentric muscle strength.
So the major challenge is to find a way to increase eccentric muscle strength without placing too much stress on my knees. I will continue with squats and dead lifts, and probably also add hang cleans as these are good for developing power in the upper leg muscles, but this program is unlikely to provide the eccentric strength required for powerful running. At this stage, hill sprints appear to offer the best option.
I have not yet formulated a detailed plan for the winter, but it will include a trial of HIIT and also lots of hill sprinting. Next year I want to focus on preparing for a marathon in the autumn, so I will begin working on endurance in the spring. Although the half marathon will not be a key target, I will probably attempt a half marathon sometime in the spring. I will not set a specific goal at this stage, but think it is reasonable to hope that a time somewhat better than yesterday’s performance will be possible.