Whilst my research focus is mainly on back pain, I have  a lot of clients with  Achilles tendinopathy, i though i might as well add a few  articles with advice on remedial treatment for sore achilles.
If you are going to a party and want to show off, you simply must drop the name  Silbernagel into the conversation. He is quite famous in coming up a type of training to help with Achilles Pain. He was part of the team  who researched “A Randomized Controlled Study Continued Sports Activity, Using a Pain-Monitoring Model, During Rehabilitation in Patients With achillies tendonosis” published in Am. J. Sports Med. 2007
That team tried this protocol:
Phase 1: Weeks 1-2 Patient status: Pain and difficulty with all activities, difficulty performing ten 1-legged toe raises
Goal: Start to exercise, gain understanding of their injury and of pain-monitoring model Treatment program: Perform exercises every day

• Pain-monitoring model information and advice on exercise activity
• Circulation exercises (moving foot up/down)
• 2-legged toe raises standing on the floor (3 sets × 10-15 repetitions/set)
•  1-legged toe raises standing on the floor (3 × 10)
• Sitting toe raises (3 × 10)
• Eccentric toe raises standing on the floor (3 × 10)

Phase 2: Weeks 2-5 Patient status: Pain with exercise, morning stiffness, pain when performing toe raises
Goal: Start strengthening Treatment program: Perform exercises every day

• 2-legged toe raises standing on edge of stair (3 × 15)
• 1-legged toe raises standing on edge of stair (3 × 15)
• Sitting toe raises (3 × 15)
• Eccentric toe raises standing on edge of stair (3 × 15)
• Quick-rebounding toe raises (3 × 20)

Phase 3: Weeks 3–12 (longer if needed) Patient status: Handled the phase 2 exercise program, no pain distally in tendon insertion, possibly decreased or increased morning stiffness
Goal: Heavier strength training, increase or start running and/or jumping activity Treatment program:
Perform exercises every day and with heavier load 2-3 times/week

• 1-legged toe raises standing on edge of stair with added weight (3 × 15) • Sitting toe raises (3 × 15)
• Eccentric toe raises standing on edge of stair with added weight (3 × 15) • Quick-rebounding toe raises (3 × 20)
• Plyometric training :Phase 4 Week 12–6 months (longer if needed)

Patient status: Minimal symptoms, morning stiffness not every day, can participate in sports without difficulty
Goal: Maintenance exercise, no symptoms Treatment program: Perform exercises 2-3 times/week