HST Log vs JuggernautAI
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
HST Log
This app guides users through a scientifically proven training program designed to maximize muscle growth. It follows a structured eight-week cycle with progressive loading and strategic deconditioning to optimize results for intermediate to advanced weightlifters.
- Scientifically proven training principles
- Eight-week structured program
- Progressive load increases
- Strategic deconditioning periods
- Focus on mechanical load stimulus
- Frequent exposure to growth stimulus
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Hypertrophy Specific Training (HST) is a scientifically proven set of training principles designed to optimize training for muscle size. Hypertrophy Specific Training is a bodybuilding program based on physiological principles of muscular growth discovered through science. Based on recent research, Hypertrophy Specific Training is the most scientifically valid way to train for muscle size and growth. In its most basic form Hypertrophy Specific Training consists of an eight week program broken up into four consecutive two week blocks. The first two weeks are spent doing 15 rep sets, starting out at a percentage of your 15 rep max the first day and progressing the load used over the course of two weeks until on the final day of those two weeks you are lifting your 15 rep max. Your muscles will become conditioned to loads and it will eventually become ineffective at causing growth, so we don't want to spend a long period of time using the same load. After a proper deload your muscles should be receptive to the lighter loads of the early 15s and should respond with growth. The point is not to lift your absolute max each workout, the point is to get growth all throughout the cycle by raising the weight consistently. Hypertrophy Specific Training operates from 4 main principles: 1. Mechanical Load - Mechanical load is the primary growth stimulus. 2. Acute vs. Chronic Stimuli - Muscle must be exposed to the growth stimulus frequently. 3. Progressive Load - Muscle tissue will adapt to the load as you continue to train. 4. Strategic Deconditioning - When progress stops or growth plateaus, it is necessary to take a break from training. Hypertrophy Specific Training is intended for intermediate to advanced weightlifters. If you are unfamiliar with weight lifting you should start with an easier program before running a Hypertrophy Specific Training cycle. Please note: The Hypertrophy Specific Training program was developed by Bryan Haycock. This is not an official HST app and may deviate from information found elsewhere.
JuggernautAI
This app uses AI to create personalized strength training programs for powerlifting and powerbuilding. It adapts to your feedback and goals, optimizing volume, frequency, and exercise selection for maximum strength gains and recovery.
- AI-generated personalized workout plans
- Powerlifting and Powerbuilding goal focus
- Adaptive training based on real-time feedback
- Optimized training frequency and volume
- Exercise selection for weak points
- Periodization strategy for fatigue management
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Juggernaut Training Systems’ revolutionary A.I. strength training system has arrived on iOS. Subscribe to JuggernautAI to access all our coaching and get stronger than you can imagine with The Smartest Program for You. Designed by legendary coach Chad Wesley Smith with revolutionary technology by Tim Arnold, JuggernautAI is like having the best strength coach in the world with you during every workout in the gym. HOW IT WORKS JuggernautAI helps you reach your strength potential using our cutting edge technology - the JuggernautAI Powerlifting and Powerbuilding system - in an efficient and easy to use way; Decide on your goal of Powerlifting, to focus on building your Squat, Bench, and Deadlift, or Powerbuilding, to balance your focus between bodybuilding and strength training. Tell us about yourself, your level of experience, and your strength goals JuggernautAI will then design a unique individualized program tailored just for you with the use of expert technology As you progress, the system will continue to adapt your training plan based on your real-time individualized feedback, ensuring you continue to grow and achieve your strength goals. WHY IT WORKS Your JuggernautAI strength program is specifically tailored to your needs and includes; ◆◆ Individualized Volume Landmarks. Do enough training to advance but not so much that you can’t recover. ◆◆ Optimized Training Frequency. Decide how many days a week you want to train, and JuggernautAI will optimize when and how often you should Squat, Bench, and Deadlift. ◆◆ Personalized Periodization Strategy. JuggernautAI finds the best way to progress to ensure you maximize your training while also managing fatigue through a strategic phasic periodization plan. ◆◆ Exercise Selection for your Weak Points. JuggernautAI looks at your weak points and your strength in individual lifts to decide which exercises will be most effective in helping you improve. As a Powerbuilding user, you can also choose which body part to focus on to ensure your physique improves the way you want it to. ◆ Real-Time Feedback Your unique individualized program continues to adapt to your feedback with our Readiness Rating System, making adjustments to your program pre-session, intra-session, session to session, week to week, block to block, and program to program Subscribe to JuggernautAI and get the smartest program for you. ———- ABOUT JUGGERNAUT TRAINING SYSTEMS Juggernaut Training Systems is The Leader in Strength, having helped thousands of athletes from beginners to World Champions maximize their results and reach their goals. We deliver principle-based coaching through cutting-edge technology to help you get the best results of your life. Privacy Policy: https://www.jtsstrength.com/app-privacy-policy/ Terms of Use: https://www.jtsstrength.com/app-terms-of-use/
Screenshots
Verdict
The clearest difference is review sentiment: JuggernautAI at 73% against HST Log's 13%. JuggernautAI also leads on rating (4.8 vs 3.1) and update cadence (every 4 days vs monthly). HST Log's advantage is monetization model (free vs subscription) and iOS requirement (9.0 vs 15.6). On price, ads, in-app purchases and device support there is nothing between them.
Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS
Both are free to download. HST Log sells 1 one-off in-app purchase and JuggernautAI sells 1 in-app purchase, starting at $34.99 per month. Whichever you choose, the download price is not the number that matters.
JuggernautAI holds the better App Store score, 4.8 against 3.1. That said, the two scores are not equally well evidenced: JuggernautAI has 5.7K ratings behind it against 11, so its average is the more settled of the two. Written reviews point the same way: 13% of HST Log's written reviews are positive against 73% of JuggernautAI's.
HST Log ships an update monthly, JuggernautAI every 4 days. Both last shipped on October 29, 2026.
| Parameter | HST Log | JuggernautAI |
|---|---|---|
| Price | Free | Free |
| Rating | 3.1 (11 ratings) | 4.8 (5.7K ratings) — better |
| Positive reviews | 12.5% of reviews | 72.7% of reviews — better |
| Number of ratings | 11 | 5.7K — better |
| Update frequency | Monthly | Every 4 days — better |
| Ads | No | No |
| In-app purchases | Yes | Yes |
| Monetization | Free — better | Subscription |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Requires iOS | 9.0 — better | 15.6 |
| Further details — not scored | ||
| Size | 18 MB | 108 MB |
| Age rating | 4+ | 17+ |
| Developer | Charles Vanderhoff | Juggernaut Apps |
Customer experience
HST Log
JuggernautAI
Bugs and requests
HST Log
Not enough reviews yet to summarise bugs or requests.
JuggernautAI
Reported bugs
3 issues- Clearing of workout history after each block
- Issues with the auto-timer feature
- Problems with selecting dates and times during setup
Requested features
4 requests- Integration with Apple Health or other fitness apps
- More flexibility in scheduling and workout days
- Improved exercise library and replacement options
- Better tracking and history of past workouts
In-app purchases
HST Log
- HST Pro$4.99
JuggernautAI
- JuggernautAI Monthly2 variants$34.991 Month
Questions
Is HST Log free?
Is JuggernautAI free?
Which has better reviews, HST Log or JuggernautAI?
Do HST Log or JuggernautAI have ads?
Which is updated more often, HST Log or JuggernautAI?
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