All cycling training programs start with goals and to a large extent the talent of the individual athlete and his or hers strengths and weaknesses. A program that an athlete WILL DO is typically better than one he/she will not do - dah. Hence we are all individuals.

Some programs and coaches that promote programs are better suited to different events. Beware of coaches, know it alls or individuals that are the cycling equivalent of men who know 150 ways to make love to a woman but do not know any women - no first hand or recent experience or credentials.

I find max heart rate and heart rate metrics in general, do not work very well. I train and race with power and have been doing so using 3rd party coaches for the last 10 years. I wear a HR monitor and smart watch and use HR metrics for recovery and head room indication. I have heart rate and sleep apps. The apps use HR and I get my sleep metrics and waking HR. I find those useful. Sleep is extremely important in recovery and making gains as an athlete. I like to monitor my HR drop after a hard effort above threshold.

My max HR is 186 but I only hit that on the track (velodrome) spinning 128 rpm in a 500 meter race. So is that a useful metric as a max HR for my 20Km time trial? No.

IMO, [MENTION=426467]rubiksoval[/MENTION] nailed it...at least for me. I do very similar workouts going general to specific driven by cycling goals. I try not to ride z1 or z2 except for warmup. I ride a lot of tempo and sweet spot BUT, I do threshold, VO2max, ANO2 and neuromuscular as well. If I were going to do stage races, long road races or long rides such as centuries, I would do long constant power z2 rides - 5 hours.

I race 20km time trials, hill climbs and individual and team events at the velodrome. I do 30 minute or longer tempo and sweet spot efforts on the time trial bike. I like to do a minimum of 20 minutes of non stop tempo or sweet spot power during a longer ride and try to do a couple of efforts. Shorter efforts (less than 20 minutes embedded in a longer ride) do not generate improvement for me and z2 rides are a waste of time. As far as threshold work, I like over unders and the minimum time for a threshold effort at 10 minutes. I like to negative split my efforts such that if I do a 4x10 minute threshold efforts, the last effort will be the best and I target 110%. I like to do workouts at the track that mix up the energy producing systems and do high power efforts mixed in with constant power efforts.

However, to mix it up a bit, I did a reverse periodization for my New Zealand cycling tour trip that I completed last week - specific to general. On the NZ tour, I rode 331 miles, 22,000 feet of climbing in 22 hours over 12 nights that included 8 days of cycling. The cycling was hard to very hard with a lot of climbing with punchy 12 to 15% grades plus long climbs. To train for that, I focused on threshold and VO2 max work with some 30on 30 off intervals. I did longer 2 to 3 hour tempo rides on the weekends. I did not go for long z2 rides in anticipation of long distances. How did it work? I felt great on the trip and generally was the first to finish a day although it was not a competition to be valedictorian of the tour. On the tour, I did not ride much z2. However, I got a lot of z1/z2 on descents and at other times when riding slower made sense for the terrain. So specific to general can work as well.

Some recommend riding a lot. If one rides a lot, one gets good at riding a lot. The question is when does one arrive at the destination? To ride fast, one has to train fast. If the only goal is to arrive then riding a lot at the target distance is a great way to train.

I have not found that riding tempo just makes one tired. I think that is mostly cycling dogma left over from the old days of RPE and HR only training. But hey, if one wants to ride around slowly in z2, have at it.

I like Coggan and Allen's model contained in Racing and Training with a Power meter. I find that most coaches adopt that model or variations thereof.

The bottom line for me has been riding at z3 for endurance and at or above threshold (a lot) has had the best yield. YMMV.