Lydiard has access to HRMs now and I have never heard of him using or even suggesting that one should use them. My bet is he would have undoubtedly said that they are not needed. As for not having access to a lab, you don’t need access to a lab or a HRM to train effectively just because you don’t have someone to prick your finger. Just as some people say with things like walking breaks or other things like that, when I see a significant number of elites using them, I’ll consider them. As of now, almost none use them and that should tell us something about the need for them.