I’d also stress the need for blood work. Prior to TR I had become the club champion at 42 (admittedly the best rider set his sights on bigger things, rather than the club championships; the 2nd best rider broke his collar bone; and my direct remaining competitor who might of beat me didn’t want to do the hill climbs, even if he was last in the HC I suspect he would have still pipped me). In summary I was in reasonable shape at 42years, if anything I was too light at 140lbs/ 5 ft 9 in. Then I had a one of blood loss which I put down as piles. My form then started to dip, and then dramatically so. People (me included) put it down as overtraining and I stupidly pressed on for 6 months or more before seeing a Doc. A simple blood test from them revealed straight away I had a chronic iron deficiency. I forget the exact numbers but it was something like 135 parts iron is normal, 35 parts is worry some, 15 is catastrophic. I was 12 after I had done the LEJOG (although two days I was in the support car, now I know why). Tests were coming back clear and I was 90% vegan I thought (wrongly again) the lack of iron was a cause of my diet. So I started eating more meat. Its only really then the classic symptoms of my then condition showed namely regular sore/ upset stomachs in addition to the fatigue (I still never saw the other major symptom, rapid weight loss, I was gaining weight slightly). As the sore stomachs got more frequent and more severe; I finally started to get very worried. Thankfully, at the same time it emerged that a rear endoscopy had been stuck in the NHS system for 3-4 months (was this because this was the one outsourced test, the inhouse front endoscopy was done within a week of my iron deficiency diagnosis 
), The rear camera found it it was a growing bowel (colon) cancer and I was in hospital for an operation the next week. Once that was whipped out though I started to recover rapidly and even through chemotherapy and two-three years later I am fitter and stronger (over distance at least) than I ever was 
. I do consider my self very lucky though, if it had burst out of the bowel it would have been game over. I am also annoyed at myself, if I had been more proactive in getting it diagnosed it might have been it could have got scraped out by the endoscopy without the need for an operation or chemo
Back to TR plans, when I initially joined TR I did feel its plans (maybe in conjunction with my first use of ERG) had too much intensity judging by the numerous niggles (in my calves/knees) I was getting but since the plans have been reworked I’ve not really had a problem, perhaps also now because I am more selective about my use of ERG.